Friday, February 20, 2009

BIO310 Introduction to Human Physiology

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23 comments:

Marysia said...
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sinchan boy said...

TASTE & SMELL(chemical sense)
>The receptors for taste (gustation) and smell (olfaction)

>Taste receptors are excited by food chemicals dissolved in saliva.

>Smell receptors, by air borne chemicals that dissolve in fluids coating nasal membranes.

TASTE.
Taste or gustation is one of the two main "chemical" senses. There are at least four types of tastes that "buds" (receptors) on the tongue detect.The inability to taste is called ageusia.

The four well-known receptors detect sweet, salt, sour, and bitter, although the receptors for sweet and bitter have not been conclusively identified.The umami receptor detects the amino acid glutamate, a flavour commonly found in meat and in artificial flavourings such as monosodium glutamate.

Note that taste is not the same as flavour; flavour includes the smell of a food as well as its taste.

SMELL.
Smell or olfaction is the other "chemical" sense.Odour molecules possess a variety of features and thus excite specific receptors more or less strongly. This combination of excitatory signals from different receptors makes up what we perceive as the molecule's smell. In the brain, olfaction is processed by the olfactory system. Olfactory receptor neurons in the nose differ from most other neurons in that they die and regenerate on a regular basis. The inability to smell is called anosmia. Some neurons in the nose are specialized to detect pheromones.

THE TASTE PATHWAY.
1) Different substances affect the membrane in different ways.

a)Bitter and sweet substances bind into receptor sites which release other substances into the cell.

b)Sour substances contain H+ ions that block channels in the membrane.

c)Salty substances break up into Na+ ions which flow through the membrane directly into the cell.

2)Electrical signals generated in the taste cells are transmitted in three pathways:

a)The chorda tympani nerve conducts signals from the front and sides of the tongue.

b)The glosso-pharyngeal nerve conducts signals from the back of the tongue.

c)The vagus nerve conducts taste signals from the mouth and the larynx.

3)These three nerves make connections in the brain stem in the nucleus of the solitary tract (NST) before going on to the thalamus and then to two regions of the frontal lobe (the insula and the frontal operculum cortex).

The Smell Pathway.
a)Olfactory transduction occurs when odorant molecules reach the olfactory mucosa and bind to the olfactory receptor proteins on the cilia of the olfactory receptor neurons.

b)When odorants bind to the receptor site, the receptor protein changes shape which in turn triggers the flow of ions across the receptor-cell membrane and an electrical response is triggered in the cilium.

c)Electrical responses in the cilia spread to the rest of the receptor cell, and from there are passed onto the olfactory bulb of the brain in the olfactory nerve.

d)There are about 1,000 different types of receptor proteins each sensitive to different odorants.

e)Inputs from similar receptor neurons go to similar glomeruli (collections of cells within the olfactory bulb). Because there are 1,000 different types of receptor neurons, there are 1,000 different types of glomeruli.

f)From the olfactory bulb, mitral cells and tufted cells carry olfactory information to the olfactory cortex, and to the orbitofrontal cortex.

ANATOMY OF TASTE.

>The tongue contains many ridges and valleys called papillae. There are four types of papillae:

>Filiform papillae: cone shaped & found all over the tongue (which is why tongues look rough)

>Fungiform papillae: mushroom shaped & found at the tip and sides of the tongue

>Foliate papillae: a series of folds along the sides of the tongue.

>Circumvallate papillae: shaped like flat mounds surrounded by a trench & found at the back of the tongue

>All papillae except filiform contain taste buds.

>Each taste bud contains a number of taste cells which have tips that protrude into the taste pore.

Anatomy of Smell.

>The Olfactory Mucosa is a dime-sized region located high inside the nasal cavity and is the site of olfactory transduction.

>The olfactory mucosa contains olfactory receptor neurons.

>Olfactory receptor neurons have cilia (little hair-like projections) which contain the olfactory receptor proteins.

Marysia said...

The lymphatic system

What is the lymphatic system?
The lymphatic system is a system of thin tubes that runs throughout the body.
 These tubes are called 'lymph vessels' or 'lymphatic vessels'. The lymphatic system is like the blood circulation – the tubes branch through all parts of the body like the arteries and veins that carry blood. But the lymphatic system carries a colorless liquid called 'lymph'. Lymph is a clear fluid that circulates around the body tissues. 
It contains a high number of lymphocytes (white blood cells).  Plasma leaks out of the capillaries to surround and bathe the body tissues. 
This then drains into the lymph vessels. The fluid, now called lymph, then flows through the lymphatic system to the biggest lymph vessel – the thoracic duct. The thoracic duct then empties back into the blood circulation.

The lymph glands
Along the lymph vessels are small bean-shaped lymph glands or 'nodes'.  You can probably feel some of your lymph nodes.
There are lymph nodes:
Under your arms, in your armpits In each groin (at the top of your legs)                   
In your neck
There are also lymph nodes that you cannot feel
in your abdomen
Your pelvis             
Your chest 

Other organs that are part of the lymphatic system
The lymphatic system includes other body organs. 
These are the:
Spleen           
Thymus           
Tonsils           
Adenoids
The spleen is under your ribs on the left side of your body.  The spleen filters lymph fluid. The thymus is a small gland under your breast bone. 
The thymus helps to produce white blood cells.  It is usually most active in teenagers and shrinks in adulthood.

What the lymphatic system does ?
The lymphatic system does several jobs in the body.  It :
Drains fluid back into the bloodstream from the tissues  
   
Filters lymph  
   
Filters the blood  
   
Fights infections


Draining fluid into the bloodstream
As the blood circulates, fluid leaks out from the blood vessels into the body tissues.  This fluid is important because it carries food to the cells and waste products back to the bloodstream.  The leaked fluid drains into the lymph vessels.  It is carried through the lymph vessels to the base of the neck where it is emptied back into the bloodstream.  This circulation of fluid through the body goes on all the time. 

Filtering lymph
The lymph nodes filter the lymph fluid as it passes through.  White blood cells attack any bacteria or viruses they find in the lymph as it flows through the lymph nodes.  If cancer cells break away from a tumor, they often become stuck in the nearest lymph nodes.  This is why doctors check the lymph nodes first when they are working out how far a cancer has grown or spread.

Fighting infection
When people say "I'm not well, my glands are up" they are really saying they have swollen lymph nodes because they have an infection.  The lymphatic system helps fight infection in many ways such as Helping to make special white blood cells (lymphocytes) that produce antibodies                   
Having other blood cells called macrophages inside the lymph nodes which swallow up and kill any foreign particles, for example germs

Disorders associated with the lymphatic system!!

The main involvement of lymph vessels are in relation to:
the spread of disease in the body
the effects of lymphatic obstruction.

Spread of disease
The materials most commonly spread via the lymph vessels from their original site to the circulating blood are fragments of tumours and infected material.
Fragments of tumours : Tumour cells may enter a lymph capillary draining a tumour, or a larger vessel when a tumour has eroded its wall. Cells from a malignant tumour, if not phagocytosed, settle and multiply in the first lymph node they encounter. Later there may be further spread to other lymph nodes, to the blood and to other parts of the body via the blood. In this sequence of events, each new metastatic tumour becomes a source of malignant cells that may spread by the same routes.
Infected material : Infected material may enter lymph vessels either at their origin in the interstitial spaces, or through the walls of larger vessels invaded by microbes when infection spreads locally . If phagocytosis is not effective the infection may spread from node to node, and eventually reach the blood stream.
Lymphangitis (infection of lymph vessel walls) : This occurs in some acute pyogenic infections in which the microbes in the lymph draining from the area infect and spread along the walls of lymph vessels, e.g. in acute Streptococcus pyogenes infection of the hand, a red line may be seen extending from the hand to the axilla. This is caused by an inflamed superficial lymph vessel and adjacent tissues. The infection may he stopped at the first lymph node or spread through the lymph drainage network to the blood.

Lymphatic obstruction
When a lymph vessel is obstructed there is an accumulation of lymph distal to the obstruction called lymphoedema. The amount of resultant swelling and the size of the area affected depend on the size of the vessel involved. Lymphoedema usually leads to low-grade inflammation and fibrosis of the lymph vessel and further lymphoedema are complications which only occur if the blockage is severe and the swelling is prolonged. The most common causes in the UK are tumours and surgery.
Tumours : A tumour may grow into, and include, a lymph vessel or node, and obstruct the flow of lymph. A large tumour outside the lymphatic system may cause sufficient pressure to stop the flow of lymph.
In other parts of the world parasitic infections can be a cause of severe forms of lymphoedema. Filariasis is an example of this and it is common in Africa resulting in the condition known as elephantiasis. This is caused by parasitic infection by a nematode worm which inhabit the lymphatics causing blockage and is transmitted to humans via mosquitoes.
Surgery : In some surgical procedures lymph nodes are removed because cancer cells may have already spread to them. This is done to prevent growth of secondary tumours and further spread via the lymphatic system. e.g. removal of the axillary nodes in mastectomy.
Enlarged lymph nodes : Lymph nodes become enlarged, (lymphadenopathy), when their work load is increased by infection. They usually return to normal when the infection subsides but if there is chronic infection or repeated acute episodes they may become fibrosed and remain enlarged. Other causes include tumours (lymphomas) and excess abnormal material in lymph, especially if present for a long time, e.g. coal dust from the lungs, necrotic material from a tumour.

Cont.
Lymphadenitis : Acute lymphadenitis is usually caused by microbes transported in lymph from other areas of infection. The nodes become inflamed, enlarged and congested with blood, and chemotaxis attracts large numbers of phagocytes When phagocytic and antibody activity are not effective the infection may lead to: · abscess formation in the node · infection of adjacent tissues · a spread of infected material to other nodes and then to the blood, causing septicaemia or bacteraemia .
Acute lymphadenitis is secondary to a number of conditions.
Infectious mononucleosis (Glandular fever) This is a highly contagious viral infection, usually of young adults, spread by direct contact. During the incubation period of 7 to 10 days viruses multiply in the epithelial cells of the pharynx. They subsequently spread to cervical nodes then to lymphatic tissue throughout the body. Clinical features include tonsilitis, lymphadenopathy and splenomegaly. A common complication is chronic fatigue syndrome. Clinical or subclinical infection confers lifelong immunity.

Other diseases connected with lymphadenitis :
Minor lymphadenitis accompanies many infections and indicates the mobilisation of normal protective resources.
More serious infection occurs in:
measles, anthrax, typhoid fever, wound and skin infections, cat-scratch fever, lymphogranuloma venereum, and bubonic plague.
Chronic lymphadenitis occurs following unresolved acute infections, in tuberculosis, syphilis and some low-grade infections.
Lymphomas
These are malignant tumours of lymphoid tissue that are classified as Hodgkin's lymphomas or non-Hodgkins lymphomas. Briefly in these diseases there is progressive painless enlargement of lymph nodes throughout the body, often noticed first in the neck.
The disease is malignant and the cause is unknown. The rate of progress varies considerably but the pattern of spread is predictable. The effectiveness of treatment depends largely on the stage of the disease at which it begins. Complications include deficiency of cell-mediated immunity, and pressure on other organs from the swollen lymph nodes.

Filtering the blood
This is the job of the spleen.  It filters the blood to take out all the old worn out red blood cells and then destroys them.  They are replaced by new red blood cells that are made in the bone marrow.  The spleen also filters out bacteria, viruses and other foreign particles found in the blood.  White blood cells in the spleen attack bacteria and viruses as they pass through.
Images on the lymphatic system disorders.

The end of presentation
Prepared by,
Marysia julius booh
2006139329

jumardi_alkhawarizmi88 said...
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Putri Edha said...

Immune SYSTEM
Prepared by; Putri Edha binti Edih
2006139283
An immune system is a collection of biological processes within an organism that protects against diseases by identifying and killing pathogens and tumor cells
detects a wide variety of agents, from viruses to parasitic worms.
Both innate and adaptive immunity depend on the ability of the immune system to distinguish between self and non-self molecules.
In immunology,
self molecules : components of an organism's body that can be distinguished from foreign substances by the immune system.
non-self molecules: recognized as foreign molecules.
-One class of non-self molecules are called antigens(short for antibody generators)
-Antibody substances that bind to specific immune receptors and elicit an immune response.
Surface barriers
Several barriers protect organisms from infection, including mechanical, chemical and biological barriers
E.g:
-The flushing action of tears and urine mechanically expels pathogens.
-while mucus secreted by the respiratory and gastrointestinal tract serves to trap and entangle microorganism.
Chemical barriers also protect against infection.
E.g:
-The skin and respiratory tract secrete antimicrobial peptides such as the β-defensins. Enzymes such as lysozyme and phospolipase A2 in saliva, tears, and breast milk are also antibacterial.
-In the Stomach, gastric acid and proteases serve as powerful chemical defenses against ingested pathogens.
Innate immune system
Microorganisms or toxins that successfully enter an organism will encounter the cells and mechanisms of the innate immune system.
The innate response is usually triggered when microbes are identified by pattern recognition receptors, which recognize components that are conserved among broad groups of microorganisms, or when damaged, injured or stressed cells send out alarm signals, many of which (but not all) are recognized by the same receptors as those that recognize pathogens.
Innate immune defenses are non-specific, meaning these systems respond to pathogens in a generic way.
This system does not confer long-lasting against a pathogen.
The innate immune system is the dominant system of host defense in most organisms.
Humoral and chemical barriers
Inflammation:
one of the first responses of the immune system to infection.
The symptoms: redness and swelling, (caused by increased blood flow into a tissue.)
Produced by eicosanoids and cytokines, which are released by injured or infected cells.
- Eicosanoids include prostaglandins that produce fever and the dilation of blood vessels associated with inflammation, and leukotrienes that attract certain white blood cells (leukocytes).
- Common cytokines include interleukins that are responsible for communication between white blood cells; chemokines that promote chemotaxis; and interferons that have anti-viral effects, such as shutting down protein synthesis in the host cell.
Complement system
A biochemical cascade that attacks the surfaces of foreign cells. It contains over 20 different proteins and is named for its ability to “complement” the killing of pathogens by antibodies.
The major humoral component of the innate immune response.
In humans, this response is activated by complement binding to antibodies that have attached to these microbes or the binding of complement proteins to carbohydrates on the surfaces of microbes.
This recognition signal triggers a rapid killing response. The speed of the response is a result of signal amplification that occurs following sequential proteolytic activation of complement molecules, which are also proteases.

Adaptive IMMUNE SYSTEM
Evolved in early vertebrates and allows for a stronger immune response as well as immunological memory, where each pathogen is "remembered" by a signature antigen.
The adaptive immune response is antigen-specific and requires the recognition of specific “non-self” antigens during a process called antigen presentation. Antigen specificity allows for the generation of responses that are tailored to specific pathogens or pathogen-infected cells.
Lymphocytes
The cells of the adaptive immune system are special types of leukocytes, called lymphocytes. B cells and T cells are the major types of lymphocytes and are derived from hematopoietic stem cells in the bone marrow. B cells are involved in the humoral immune response, whereas T cells are involved in cell-mediated immune response.
Association of a T cell with MHC class I or MHC class II, and antigen (in red)
Both B cells and T cells carry receptor molecules that recognize specific targets. T cells recognize a “non-self” target, such as a pathogen, only after antigens (small fragments of the pathogen) have been processed and presented in combination with a “self” receptor called a major histocompatibility complex (MHC) molecule.
There are two major subtypes of T cells: the killer T cell and the helper T cell.
Killer T cells only recognize antigens coupled to Class I MHC molecules,
helper T cells only recognize antigens coupled to Class II MHC molecules. These two mechanisms of antigen presentation reflect the different roles of the two types of T cell.
In contrast, the B cell antigen-specific receptor is an antibody molecule on the B cell surface, and recognizes whole pathogens without any need for antigen processing.
Each lineage of B cell expresses a different antibody, so the complete set of B cell antigen receptors represent all the antibodies that the body can manufacture.

Killer T cells & Helper T cells
Killer T cell are a sub-group of T cell -kill cells infected with viruses (and other pathogens), or are otherwise damaged or dysfunctional. As with B cells, each type of T cell recognises a different antigen.
Helper T cells regulate both the innate and adaptive immune responses and help determine which types of immune responses the body will make to a particular pathogen.These cells have no cytotoxic activity and do not kill infected cells or clear pathogens directly. They instead control the immune response by directing other cells to perform these tasks.
B lymphocytes and antibodies
A B cell identifies pathogens when antibodies on its surface bind to a specific foreign antigen.
This antigen/antibody complex is taken up by the B cell and processed by proteolysis into peptides. The B cell then displays these antigenic peptides on its surface MHC class II molecules. This combination of MHC and antigen attracts a matching helper T cell, which releases lymphokines and activates the B cell.
As the activated B cell then begins to divide, its offspring (plasma cells) secrete millions of copies of the antibody that recognizes this antigen. These antibodies circulate in blood plasma and lymph, bind to pathogens expressing the antigen and mark them for destruction by complement activation or for uptake and destruction by phagocytes.
Antibodies can also neutralize challenges directly, by binding to bacterial toxins or by interfering with the receptors that viruses and bacteria use to infect cells
INTERFERON(IFNs)
Certain antimicrobial substances
Provide a second line of defense should microbes penetrate the skin and mucous membranes
proteins produced by lymphocytes, macrophages, and fibroblasts infected with viruses.
diffuse to neighboring cells and stimulate them to produce antiviral proteins that interfere with viral replication
Do not protect the original infected cell
Do not prevent viruses from attaching to and penetrating host cells.
protect the neighboring cells by interfering with viral replication
three types of interferon:             -alpha- IFN                       -beta-IFN                         -gamma-IFN
Disorders of human immunity

Immunodeficiencies
Occur when one or more of the components of the immune system are inactive.
The ability of the immune system to respond to pathogens is diminished in both the young and the elderly, with immune responses beginning to decline at around 50 years of age due to immunosenescence.
Malnutrition is the most common cause of immunodeficiency in developing countries.
Diets lacking sufficient protein are associated with impaired cell-mediated immunity, complement activity, phagocyte function, IgA antibody concentrations, and cytokine production. Deficiency of single nutrients such as iron; copper; zinc; selenium; vitamins A, C, E, and B6; and folic acid(vitamin B9) also reduces immune responses.
Immunodeficiencies can also be inherited or 'acquired'.
Chronic granulomatous disease, where phagocytes have a reduced ability to destroy pathogens, is an example of an inherited, or congenital, immunodeficiency. AIDS and some types of cancer cause acquired immunodeficiency.

Autoimmunity
Overactive immune responses comprise the other end of immune dysfunction, particularly the autoimmune disorders.
The immune system fails to properly distinguish between self and non-self, and attacks part of the body.
Under normal circumstances, many T cells and antibodies react with “self” peptides.
Human autoimmune diseases:
- Rheumatoid rthritis (RA), rheumatic fever, glomerulonephritis, hemolytic and pernicious anemias, Addison’s disease,type I diabetes mellitus and multiple sclerosis (MS)

Hypersensitivity (Allergy)
Person who is overly reactive to an antigen.
Common allergens:
- certain foods, antibiotics(penicilin, tetracycline), vitamins, cosmetics,chemicals in plants(poison ivy, pollens) dust, molds and even microbes.
Allergic reactions:
Localized ( affecting one part or limited area) : hives, eczema, abdominal cramps& diarrhea
Systemic (affecting several parts or the entire body):
acute anaphylaxis (respiratory symptom) as bronchioles constrict-Wheezing and shortness breath , cardiovascular failure and fluid loss from blood.
Divided into four classes (Type I – IV) based on the mechanisms involved and the time course of the hypersensitive reaction.
Type I hypersenIMMUNE sitivity -an immediate or anaphylactic reaction.
- Mediated by IgE released from mast cells and basophils
-Symptoms can range from mild discomfort to death.
Type II hypersensitivity occurs when antibodies bind to antigens on the patient's own cells, marking them for destruction.
-Called antibody-dependent (or cytotoxic) hypersensitivity, and is mediated by IgG and IgM antibodies.
Immune complexes (aggregations of antigens, complement proteins, and IgG and IgM antibodies) deposited in various tissues trigger Type III hypersensitivity reactions.
Type IV hypersensitivity (known as cell-mediated or delayed type hypersensitivity)
-takes between two and three days to develop.
-Involved in many autoimmune and infectious diseases, but may also involve contact dermatitis (poison ivy).
-Mediated by T cells, monocytes, and macrophages.

Deborah said...

TOPIC: BLOOD TRANSFUSION AND BLOOD REPLACEMENT
NAME: DEBORAH DAVID HENRY
MATRIKS NO: 2006156779

THE DISCOVERY OF BLOOD GROUP
 Experiments with blood transfusion; the transfer of blood or blood components into a person's blood stream, have been carried out for hundreds of years.
 Many patients have died and it was not until 1901, when the Austrian Karl Landsteiner discovered human blood groups, that blood transfusions became safer.
 Mixing blood from two individuals can lead to blood clumping or agglutination. The clumped red cells can crack and cause toxic reactions. This can have fatal consequences.
 Karl Landsteiner discovered that blood clumping was an immunological reaction which occurs when the receiver of a blood transfusion has antibodies against the donor blood cells.


WHAT IS BLOOD MADE OF?
 The red blood cell contain hemoglobin, a protein that binds oxygen. Red blood cells transport oxygen to and remove carbon dioxide from the body tissues.
 The white blood cells fight infection.
 The platelets help the blood to clot, if you get a wound for example.
 The plasma contains salts and various kinds of proteins.



THE DIFFERENT BLOOD GROUP
 The differences of human blood are due to the presence or absence of certain protein molecules called the antigens and antibodies.
 The antigens are located on the surface of the red blood cells and the antibodies are in the blood plasma.
 There are more than 20 genetically determined blood group systems known today, but the ABO and Rh systems are the most important ones for blood transfusions.


WHAT HAPPENS WHEN THE BLOOD CLUMPS OR AGGLUTINATES?
 For a blood transfusion to be successful, ABO and Rh blood group must be compatible between the donor blood and the patients blood, or not the red blood cells from the donated blood will clump or agglutinate.
 The agglutinated red cells can clog blood vessels and stop the circulation of the blood to various parts of the body. It also crack and leaks it contain out in the body.
 The red blood cells contain hemoglobin which becomes toxic outside the cells and this can gave fatal consequences for the patient.


WHAT IS THE RISK OF BLOOD TRANSFUSION?
 Most blood transfusions go very smoothly. However, mild problems and, very rarely, serious problems can occur.
 A transfusion is stopped at the first signs of an allergic reaction. The health care team determines how mild or severe the reaction is, what treatments are needed, and if the transfusion can safely be restarted.
ALLERGIC REACTION;
 Allergic reactions can be mild or severe. Symptoms can include:
 Anxiety
 Chest and/or back pain
 Trouble breathing
 Fever, chills, flushing, and clammy skin
 A high pulse or low blood pressure
 Nausea (feeling sick to the stomach)

WHAT IS THE RISK OF BLOOD TRANSFUSION?
VIRUSES AND INFECTIOUS DISEASE
 There is a risk of catching a virus from a blood transfusion, but it's very low, some of the disease are;
 HIV
 Hepatitis B
 Hepatitis C
 Fever
 Iron overload
 Lung injury
 Acute Immune Hemolytic Reaction
 Delayed Hemolytic Reaction
 Graft-Versus-Host Disease





TYPES OF BLOOD TRANSFUSION
Red Blood Cell Transfusions
 Red blood cells are the most commonly transfused part of the blood. These cells carry oxygen from the lungs to your body's organs and tissues. They also help your body get rid of carbon dioxide and other waste products. You may need a transfusion of red blood cells if you've lost blood due to an injury or surgery.

 You also may need this type of transfusion if you have severe anemia due to disease or blood loss. Anemia is a condition in which your blood has a lower than normal numbers of red blood cells or the red blood cells don’t have enough hemoglobin. Hemoglobin is an iron-rich protein that gives blood its red color carries oxygen from the lungs to the rest of the body.


TYPES OF BLOOD TRANSFUSION
Platelets and Clotting Factor Transfusions
 Platelets and clotting factors help stop bleeding, including internal bleeding that you can't see. Some illnesses may cause your body to not make enough platelets or other clotting factors. You may need regular transfusions of these parts of your blood to stay healthy.
 For example, if you have hemophilia A, you may need a special clotting factor to replace the clotting factor you're lacking. Hemophilia is a rare, inherited bleeding disorder in which your blood doesn't clot normally.
 If you have hemophilia, you may bleed for a longer time than others after an injury or accident. You also may bleed internally, especially in the joints (knees, ankles, and elbows).


TYPES OF TRANSFUSION
Plasma Transfusions
 Plasma is the liquid part of your blood. It's mainly water, but also contains proteins, clotting factors, hormones, vitamins, cholesterol, sugar, sodium, potassium, calcium, and more.
 If you have been badly burned or have liver failure or a severe infection, you may need a plasma transfusion.


THANK YOU
Q & A

Anjula said...

Anjula Majadul
2006139333

COPD-Chronic Obstructive Pulmonary Disease

What is COPD?
A progressive disease that makes it hard to breathe.

"Progressive" means the disease gets worse over time.

COPD can cause coughing that produces large amounts of mucus (a slimy substance), wheezing, shortness of breath, chest tightness, and other symptoms.



In contrast to asthma, the limitation of airflow is poorly reversible and usually gets progressively worse over time.


Cigarette smoking is the leading cause of COPD. Most people who have COPD smoke or used to smoke.

Long-term exposure to other lung irritants, such as air pollution, chemical fumes, or dust, also may contribute to COPD.
Other Name of COPD
Chronic obstructive lung disease (COLD).
Chronic obstructive airway disease (COAD).
Chronic airflow limitation (CAL) .
Chronic obstructive respiratory disease.
Causes of COPD
Smoking
- Smoking is responsible for 90% of
COPD in the United States.
- Smokers with COPD have higher death
rates than nonsmokers with COPD.
- Inhaling the smoke from other peoples'
cigarettes (passive smoking) can lead to
impaired lung growth and could be a cause of
COPD.


2. Air Pollution
- People who live in large cities have a
higher rate of COPD compared to people
who live in rural areas.
-In many developing countries indoor air
pollution from cooking fire smoke (often using
biomass fuels such as wood and animal dung)
is a common cause of COPD, especially in
women.

3. Occupational Exposures
-Intense and prolonged exposure to workplace
dusts found in coal mining, gold mining, and the
cotton textile industry and chemicals such as
cadmium, isocyanates, and fumes from welding
have been implicated in the development of
airflow obstruction, even in nonsmokers.

-Intense silica dust exposure causes silicosis, a
restrictive lung disease distinct from COPD;
however, less intense silica dust exposures
have been linked to a COPD-like condition.

4. Genetics
- Alpha 1-antitrypsin deficiency is a genetic
condition that is responsible for about 2% of
cases of COPD.
- In this condition, the body does not make
enough of a protein, alpha 1-antitrypsin.
- Alpha 1-antitrypsin protects the lungs from
damage caused by protease enzymes, such as
trypsin, that can be released as a result of an
inflammatory response to tobacco smoke.

The manufacture of AAT by the liver is controlled by genes which are contained in DNA-containing chromosomes that are inherited.
Each person has two AAT genes, one inherited from each parent.
Individuals with one normal and one defective AAT gene have AAT levels that are lower than normal but higher than individuals with two defective genes.
These individuals MAY have an increased risk of developing COPD if they do not smoke cigarettes; however, their risk of COPD probably is higher than normal if they smoke.
Signs and Symptoms
Shortness of breath (dyspnea).
-People with COPD typically first notice
dyspnea during vigorous exercise when
the demands on the lungs are greatest.

A persistent cough, sputum or mucus production, wheezing, chest tightness, and tiredness.

Tachypnea, a rapid breathing rate.
wheezing sounds or crackles in the lungs heard through a stethoscope.
breathing out taking a longer time than breathing in .
enlargement of the chest, particularly the front-to-back distance (hyperinflation).
active use of muscles in the neck to help with breathing
breathing through pursed lips.
increased anteroposterior to lateral ratio of the chest
(i.e. barrel chest).

Diagnosis
Chest x-ray.
Computerized tomography (CT or CAT scan) of the chest.
Tests of lung function (pulmonary function tests).
The measurement of oxygen and carbon dioxide levels in the blood.


Sometimes COPD is first diagnosed after a patient develops a respiratory illness necessitating hospitalization.

Some physical findings of COPD include enlarged chest cavity and wheezing.


Treatment
1) Quitting smoking.
2) Taking medications to dilate airways (bronchodilators) and decrease airway inflammation.
3) Vaccinating against flu influenza and pneumonia.
4) regular oxygen supplementation.
5) pulmonary rehabilitation.
What else is available for treating COPD?
Pulmonary rehabilitation is a program of education regarding lung function and dysfunction, proper breathing techniques (diaphragmatic breathing, pursed lip breathing), and proper use of respiratory equipment and medications.

In addition, occupational and physical therapy are used to teach optimal and efficient body mechanics.

Lung volume reduction surgery (LVRS) is a surgical procedure used to treat some patients with COPD.

Jessey said...

Name:Jessey Angat
Matrix Number:2006147045
CLEANING UP: URINARY SYSTEM

URINE
Body’s primary waste product.
Release of urine - final step of all metabolism.
The waste product of metabolism – the conversion of fuel to energy used in body – go back into the bloodstream and are filtered out and then the urinary system removes them out.
ANATOMY
TAKING OUT THE TRASH; THE KIDNEYS

The kidneys are bean-shaped organs about the size of your fists.
They are near the middle of the back, just below the rib cage.
The kidneys remove urea from the blood through tiny filtering units called nephrons – miroscopic unit that filters blood & creates urine.
Each nephron consists of a ball formed of small blood capillaries, called a glomerulus, and a small tube called a renal tubule.
Urea, together with water & other waste substances, forms the urine as it passes through the nephrons and down the renal tubules of the kidney.
TRAVELLING YOUR URETERS

Ureters – tubes that transport the urine created in each kidney to the bladder.
Made up of three layers ; an outer covering, a muscular layer, & a mucuos layer lining the tube’s inside.
The muscular layer contracts in waves of peristalsis – moves urine from kidney to the bladder
STORING URINE IN YOUR BLADDER
Holding tank – a hollow sac into which urine is deposited from the kidneys through the ureters
Made up of an outer protective membrane, several layers of muscles arranged in different directions, & an inner muscolar layer.
The muscle layers allow the bladder to expand and contract depending on how much urine inside it.
Maximum amount of urine that it can hold – 600 ml
EXPELLING URINE OUT YOUR URETHRA
Urethra – tube that carries urine from bladder to an opening (orificea) of the body during – micturition process
Females – length;3.8 cm & it ends at the urethral orifice in the anterior wall of the vagina between the clitoris & the vaginak orifice.
Males – lentgh;20 cm & runs down through the prostate gland and the penis, which has an opening on the tip called the urethral meatus.

KIDNEY’S FUNCTION
1) Maintaining homeostasis
Maintaining the proper balance between the salt & water content of your blood.
Maintaining the proper Ph (acid-base) level of the blood


2) Balancing acts
Water – lost from your body when your urine is diluted, and your body conserves water when your urine is concentrated.
Kidneys – regulate whether water your body releases or conserves water.
3)Monitoring your blood pressure
Kidneys – use the processes of tubular secretion & tubular reabsorption – remove and replace salts & water from your blood.

4) Regulating your pH
Detect the ph of your body;if too low – acidic- amino acid glutamine is broken down.
Metabolism of glutamine – ammonia – transported into the filtrate that become the concentrated urine, sodium ions move back into the bloodstream & continue buffer.
DISEASES & DISORDER
BENIGN PROSTATIC HYPERLASIA (BPH)
Condition in men that affects the prostate gland, which is part of the male reproductive system.
BPH - an enlargement of the prostate gland that can interfere with urinary function in older men - causes blockage by squeezing the urethra, which can make it difficult to urinate.
Men with BPH frequently have other bladder symptoms including an increase in frequency of bladder emptying both during the day and at night .

KIDNEY STONES
Commonly used to refer to stones, or calculi, in the urinary system.
Stones form in the kidneys and may be found anywhere in the urinary system - vary in size.
Some stones cause great pain while others cause very little.
The aim of treatment is to remove the stones, prevent infection, and prevent recurrence - both nonsurgical and surgical treatments are used.
Kidney stones affect men more often than women.
PROSTATITIS
Inflammation of the prostate gland that results in urinary frequency & urgency, burning or painful urination, a condition called dysuria, and pain in the lower back and genital area, among other symptoms.
In some cases - prostatitis is caused by bacterial infection and can be treated with antibiotics.
More common forms of prostatitis are not associated with any known infecting organism.
Antibiotics are often ineffective in treating the nonbacterial forms of prostatitis.
PROTEINURIA
The presence of abnormal amounts of protein in the urine.
Healthy kidneys take wastes out of the blood but leave in protein.
Protein in the urine does not cause a problem by itself - but it may be a sign that your kidneys are not working properly.
URINARY TRACT INFECTIONS (UTIs)
Caused by bacteria in the urinary tract.
Women get UTIs more often than men.
UTIs are treated with antibiotics.
Drinking lots of fluids also helps by flushing out the bacteria.
URINARY INCONTINENCE
Loss of bladder control, is the involuntary passage of urine
There are many causes & types of incontinence, & many treatment options.
Treatments range from simple exercises to surgery.
Women are affected by urinary incontinence more often than men.
URINARY RETENTION
Common urological problem with many possible causes.
Normally, urination can be initiated voluntarily and the bladder empties completely.
Urinary retention is the abnormal holding of urine in the bladder. Acute urinary retention - the sudden inability to urinate, causing pain and discomfort.
Causes can include an obstruction in the urinary system, stress, or neurologic problems.
Chronic urinary retention refers to the persistent presence of urine left in the bladder after incomplete emptying. Common causes of chronic urinary retention are bladder muscle failure, nerve damage, or obstructions in the urinary tract.
Treatment for urinary retention depends on the cause.
RENAL(KIDNEY) FAILURE
Kidneys are not able to regulate water & chemicals in the body or remove waste products from your blood.
Acute renal failure (ARF) - is the sudden onset of kidney failure.
This condition can be caused by an accident that injures the kidneys, loss of a lot of blood, or some drugs or poisons.
ARF may lead to permanent loss of kidney function - but if the kidneys are not seriously damaged, they may recover.
Chronic kidney disease (CKD) is the gradual reduction of kidney function that may lead to permanent kidney failure, or end-stage renal disease (ESRD).
You may go several years without knowing you have CKD.
THANK YOU

m@nn said...

Nmae:usman bin saharun
matrix No: 2006139317
Title:The Ear (hearing & Balance)


>INTRODUCTION<

# Hearing one of the five senses.
# Has three main parts:
i) Outer ear
ii) Middle
iii)Inner ear
# Structure of the ear:
- www.britannica.com/EBchecked/topic/175622/ear


>HearinG<

# Five sections of the hearing mechanism:
i) Outer ear
ii) Middle ear
iii) Inner ear
iv) Acoustic nerve
v)Brain’s auditory processing centers

> Outer ear

# Consists of the pinna, or auricle and the ear canal(external auditory meatus)

.The pinna or auricle:
- Made of cartilage and soft tissue so that it maintains a particular shape but is also pliable.
- Serves as a collector of sound vibrations around us and funnels the vibrations into the ear canal.
It assists us in determining the direction and source of sound.

.The ear canal ( external auditory meatus ):
- It is about an inch long and ¼ inch in diameter. It extends from the pinna to the eardrum (tympanic membrane)
- The outer foundation of the ear canal is cartilage covered with skin that contains hairs and glands that secrete wax (cerumen)
- The hairs and wax help to prevent foreign bodies, such as insects or dust, from entering the ear canal
- Near the eardrum ( tympanic membrane ), the wall of the ear canal becomes bony and covered tightly by skin

> Middle ear

# It is begins with the eardrum at the end of the ear canal.
# Contains three tiny bones called the ossicles. That is:
i) Hammer (malleus) that connected to the eardrum.
ii) Anvil ( incus ), that connects to the third bone.
# Stirrup ( stapes ) footplate fits into the oval window, the beginning point of the inner ear.
# The ossicles structure:
- www.medway.nhs.uk/.../index.html
# The mechanical energy transmitted through the three bones (ossicular chain) causes the in-and-out movement of the base of the stirrup ( stapes footplate ) in patterns that match those of the incoming sound waves.
Contain of a tube called the eustachian tube.
# The eustachian tube:
- Runs from the front wall of the middle ear down to the back of the nose and throat (the nasopharynx ).
Provides ventilation and access to outside air and equalizes air pressure on both sides of the eardrum

> Inner ear

# It contains the sensory organs for hearing and balance.
- For hearing:
Cochlea is the hearing part of the inner ear.
- For balance:
The semicircular canals , the utricle and the saccule are the balance part of the inner ear.

# The Cochlea :
- It is a bony structure shaped like a snail and filled with fluid (endolymph and perilymph ).
Contains the Organ of Corti (the sensory receptor), which holds the hair cells , the nerve receptors for hearing.
# The mechanical energy:
from movement of the middle ear bones pushes in a membrane (the oval window) moves the cochlea's fluids that, in turn, stimulate tiny hair cells. Signals from these hair cells are translated into nerve impulses. The nerve impulses are transmitted to the brain by the cochlear portion of the acoustic nerve (VIII cranial nerve)

> Acousti nerve

# It carries impulses from the cochlea to a relay station in the mid-brain, the cochlear nucleus, and on to other brain pathways that end in the auditory cortex of the brain.
# In itself, nerve fibers from each ear divide into two pathways.
# The pathway:
- One pathway ascends straight to the auditory cortex on one side (hemisphere) of the brain.
- The other pathway crosses over and ascends to the auditory cortex on the other side (hemisphere) of the brain.
# As a result, each hemisphere of the brain receives information from both ears.

> central auditory system

# It deals with the processing of auditory information as it is carried up to the brain.
# Central auditory processes are the auditory processes responsible for the following behaviors:
- Sound localization and lateralization
- Auditory discrimination (hearing the differences between different sounds).
- Recognizing patterns of sounds.
- Time aspects of hearing (temporal aspects of audition): temporal resolution, temporal masking, temporal integration, temporal ordering.
- Reduction in auditory performance in the presence of competing acoustic signals.
- Reduction in auditory performance in the presence of degraded (less than complete) acoustic signals.

> Balance <

# It is controlled through the vestibular system that is also contained in the inner ear.
# Vestibular system:
- Consist of three semicircular canals , the utricle , and the saccule.
- It lies anatomically in a different plane, each plane at a right angle to each other. Then, make it deals with different movement: up and down, side to side, and tilting from one side to the other.
- It contain sensory hair cells that are activated by movement of inner ear fluid (endolymph).
- The ends of the semicircular canals connect with the utricle, and the utricle connects with the saccule.
- The semicircular canals provide information about movement of the head, the sensory hair cells of the utricle and saccule provide information to the brain (again through the vestibular portion of the acoustic nerve) about head position when it is not moving.

> Sounds <

# It is measured in decibels (dB), where each decibel is one tenth of a bel, which is a unit that measures the intensity of sound.
# For every six decibels, the intensity of the sound doubles.   At 90 dB of uninterrupted sound, the limit of safe noise exposure is eight hours.  For each six dB increase of uninterrupted sound thereafter, the limit of safe exposure is reduced by half.
#The approximate intensity of sound around us to protect our hearing.

terans said...

Human Respiration (Control of breathing)

Prepared by:
Terans Bin Thadeus
2006111055
BIO 310

-The major function of the lung is to get oxygen into the body and carbon dioxide out.
-Respiration failure occur when lung Inability to transfer oxygen and/or carbon dioxide between the atmosphere and the blood.

Human Respiration
-Consists of cellular respiration and gas exchange or breathing
Follows typical aerobic respiration
Without oxygen, anaerobic reispiration occurs and lactic acid forms in the muscles
Allows for gas exchange with the external environment

Nasal Cavity
-Exposed to air through nostrils
Lined with ciliated (hairs) mucous membrane
Filters, warms, and moistens the air

On to the Pharynx
-Pharynx
Where the oral and nasal cavity meet.
Epiglottis prevents.

Larynx
-Between the Pharynx and your Trachea is you larynx or voice box.

From the Pharynx to the Trachea
-Trachea
Conducts air between the pharynx and bronchi
Kept open by partial rings of cartilage
Line with a ciliated mucous membrane

Bronchi
-Bronchi
Trachea splits into two (2) bronchi
Same composition as trachea

Bronchioles
-Bronchi split up into many bronchiole:
lined mucous membrane but lack cartilage

Breathing
-Caused by changing pressure in the chest cavity
Rate is affected by the amount of CO2 in the blood
Affects the medulla of the brain
It’s a feedback mechanism.

Neural control of breathing
-Voluntary control: located in cerebral cortex.
-Automatic control: pacemaker cells in medulla.
-Final common path: motor neurons of respiratory muscles

How is does the pressure change in the chest cavity?
-The diaphragm:
A shelf of muscle extending between the thorax and abdomen of mammals
In other words it is a muscle at the bottom of the chest cavity the expands and contracts.
When the diaphragm expands, in enlarges the chest cavity creating a low pressure inside the lungs which causes air to rush into the lungs
When the diaphragm contracts, in makes the chest cavity smaller, increasing the pressure, pushing air out of the lungs.

What happens to the oxygen?
-Oxygen is carried by hemoglobin in a cell called oxyhemoglobin
Carbon dioxide is carried in the plasma of the blood in the form of a bicarbonate ion.

LUNG VOLUMES
1. Tidal Volume (Vt) – is the volume of air inspired or expired with each normal breath - 500 ml
2. Inspiratory Reserve Volume (IRV) – the extra volume of air that can be inspired over and above the normal tidal volume when the person inspires with full force – 3000ml
3. Expiratory Reserve Volume (ERV)– is the maximum extra volume of air that can be expired by forceful expiration after the end of the normal tidal expiration - 1100 ml

4. Residual Volume (RV) – the volume of air remaining in the lungs after the most forceful expiration – 1200ml
5. Vital capacity – is the sum of the inspiratory reverse volume,the tidal volume, and the expiratory reverse volume.(about 4600ml)

Rhythmic ventilation
- The normal rate respiration in adults is between 12 and 20 respiration per minute.
In children, the rates are higher and may vary from 20 to 40 per minutes.
-Ventilation controlled by neurons.
The rate of respiration is determined by the number of times respiratory muscles are stimulated.

FACTORS AFFECTING LUNG VOLUMES
-Body build or physique
-Position of the body
-Strength of respiratory muscles
-Pulmonary compliance

Malfunctions
-Bronchitis:
Inflammation of the membrane of bronchial tubes caused by infection
-Asthma
Allergic response characterized by constriction of bronchial tubes.
-Emphysema:
Change in the structure pf the lung characterized by enlargement or degeneration of the alveoli
Loss of elasticity and lung capacity
Caused by highly polluted air or cigarette smoke



Thank You.

fiffy said...

GENETIC
The Vocabulary of Genetics
&
Sexual Sources of Genetic Variation


Vocabulary of Genetics
Genetics: is the scientific study of heredity and variation.
Variation: offspring exhibit individually, differing somewhat in appearance from parents and siblings.
Genes: parents endow their offspring with coded information in the form of hereditary units.
Gene: one of many discrete units of hereditary information located on the chromosomes and consisting of DNA.




Allele: alternative forms of a gene for each variation of a trait of an organism.
Dominant: observed trait of an organism that mask the recessive form of a trait.
Genotype: combination of genes in an organism.
Hybrid: offspring formed by parents having different forms of a specific trait.
Phenotype : outward appearance of an organism, regardless of its genes.

http://www.ric.edu/faculty/ptiskus/peas/Genetics%20Vocabulary.htm
Sex Determination
Human has 23 pairs of chromosomes.
22 pairs are identical in both sexes, however, the 23rd pair is different in male from the female.
Female XX ( homogametic sex)
Male XY (heterogametic sex)
Sources of Genetic Variation
DNA Mutation
Sexual reproduction
Sexual Reproduction
Independent assortment
Crossing over
Random fertilization

http://www.ucopenaccess.org/courses/CPBiology/bio_3_2_3_4.swf
Independent Assortment
discovered by a monk named Gregor Mendel in the 1860's.
states that the alleles for a trait separate when gametes are formed.
Mutations occur during DNA replication prior to meiosis. Crossing over during metaphase I mixes alleles from different homologues into new combinations


Crossing over
is the process by which two chromosomes pair up and exchange sections of their DNA.
This often occurs during prophase 1 of meiosis in a process called synapsis.
Crossover usually occurs when matching regions on matching chromosomes break and then reconnect to the other chromosome. The result of this process is an exchange of genes, called genetic recombination.

Chromosomal crossovers also occur in asexual organisms and in somatic cells, since they are important in some forms of DNA repair.

Random fertilization
Fertilization randomly brings together two gametes produced in two different individuals.
Random fertilization is a further mechanism that produces genetic variation in the process of sexual reproduction.




Q & A
Thank You……<(^.^)>!!!

asy_syuura said...

ASYSYUURA ADYTIA BT PATAR
2006147061
BIO 310

HEART ANATOMY

INTRODUCTION
• Heart is a muscular organ in all vertebrates responsible for pumping blood through the blood vessels as delivery routes.
• The heart of a vertebrate is composed of cardiac muscle, an involuntary muscle tissue which is found only within this organ.


CHARACTERISTICS

• Heart is located under the ribcage in the center of our chest between our right and left lung.
• It’s shaped like an upside-down pear.
• The average human heart beating at 72 beats per minute, will beat approximately 2.5 billion times during a lifetime (about 66 years).
• Each day, the average heart beats 100,000 times, pumping about 2,000 gallons (7,571 liters) of blood.
• It weighs on average 250 g to 300 g in females and 300 g to 350 g in males.
• The size of our heart can vary depending on our age, size or the condition of our heart.

STRUCTURES OF HEART

• CORONARY ARTERIES
o network of blood vessels that carry oxygen- and nutrient-rich blood to the cardiac muscle tissue.
• VENA CAVA
o Superior & Inferior
o veins bringing de-oxygenated blood from the body to the heart.
• AORTA
o vessel carries oxygen-rich blood from the left ventricle to the various parts of the body.

• PULMONARY ARTERY
o vessel transporting de-oxygenated blood from the right ventricle to the lungs.

• PULMONARY VEIN
o vessel transporting oxygen-rich blood from the lungs to the left atrium.

• RIGHT ATRIUM
o receives de-oxygenated blood from the body through the superior vena cava and inferior vena cava.
• LEFT ATRIUM
o receives oxygenated blood from the lungs through the pulmonary vein.

• RIGHT VENTRICLE
o receives de-oxygenated blood as the right atrium contracts.
• LEFT VENTRICLE
o receives oxygenated blood as the left atrium contracts.
• PAPILLARY MUSCLES
o effect the opening and closing of valves.
• CHORDAE TENDINEAE
o tendons linking the papillary muscles to the tricuspid valve in the right ventricle and the mitral valve in the left ventricle.
• VALVES
o Tricuspid
o separates the right atrium from the right ventricle.
o Mitral
o separates the left atrium from the left ventricle.
o Pulmonary
o separates the right ventricle from the pulmonary artery.
o Aortic
o separates the left ventricle from the aorta.

HISTORY OF DISCOVERIES

• Anatomy of heart
o modern understanding by cardiologist Dr. Francesc Torrent-Guasp (1997).
o describes the heart as a single band of muscle starting at the pulmonary artery and ending below the aorta exit.
o This band wraps itself into a double helical coil that bounds both ventricular cavities with a wall that separates them.
o His model also describes how this band progressively contracts leading to ejection and suction of the blood.
o This model has been a major achievement, since it was widely believed until then that blood entered the left ventricle passively.


HEART DEVELOPMENT

• The mammalian heart is derived from embryonic mesoderm germ-layer cells that differentiate after gastrulation into mesothelium, endothelium, and myocardium.
• Mesothelial pericardium forms the inner lining of the heart.
• The outer lining of the heart, lymphatic and blood vessels develop from endothelium.
• Myocardium develops into heart muscle.
• The human embryonic heart begins beating around 23 days after conception, or five weeks after the last normal menstrual period (LMP), which is the date normally used to date pregnancy.
• It is unknown how blood in the human embryo circulates for the first 21 days in the absence of a functioning heart.
• The human heart begins beating at a rate near the mother’s, about 75-80 beats per minute (BPM).
• There is no difference in male and female heart rates before birth.


DEVELOPMENT PROCESS

• From splachnopleuric tissue, the cardiogenic plate develops cranially and laterally to the neutral plate.
• Two angiogenic cell clusters form on either side of the embryo
• Each cell cluster form an endocardial tube continuous with dorsal aorta & vitteloumbilical vein
• Embryonic tissue fold
• Two endocardial tubes pushed into thoracic cavity
• Fuse together until approximately complete at 21 days
• Human hearts begins beating at 70-80 beats per minute (bpm)& accelerates constantly for the 1st month
• Peaking during the early 7th week to 165-185 bpm
• Decelerates to about 152 bpm during week 9-15
• After 15th week, start to reach average rate of about 145 bpm at term

Jay Denis said...

• Heart Physiology
Prepared by:
Vijay Govindan Denis Eswar
2006111273
• The physical of heart
The heart is the muscular organ of the circulatory system that constantly pumps blood throughout the body.
Approximately the size of a clenched fist, the heart is composed of cardiac muscle tissue that is very strong and able to contract and relax rhythmically throughout a person's lifetime.
The heart has four separate compartments or chambers. The upper chamber on each side of the heart, which is called an atrium, receives and collects the blood coming to the heart. The atrium then delivers blood to the powerful lower chamber, called a ventricle, which pumps blood away from the heart through powerful, rhythmic contractions.
The human heart is actually two pumps in one.
The right side receives oxygen-poor blood from the various regions of the body and delivers it to the lungs.
In the lungs, oxygen is absorbed in the blood. The left side of the heart receives the oxygen-rich blood from the lungs and delivers it to the rest of the body.
• Pumping action of the heart
The pumping action starts with the simultaneous contraction of the two atria.
This contraction serves to give an added push to get the blood into the ventricles at the end of the slow-filling portion of the pumping cycle called "diastole." Shortly after that, the ventricles contract, marking the beginning of "systole."
The aortic and pulmonary valves open and blood is forcibly ejected from the ventricles, while the mitral and tricuspid valves close to prevent backflow.
At the same time, the atria start to fill with blood again.
When the ventricles relax, the aortic and pulmonary valves close, and the mitral and tricuspid valves open and the ventricles start to fill with blood again. marking the end of systole and the beginning of diastole.
Even though equal volumes are ejected from the right and the left heart, the left ventricle generates a much higher pressure than does the right ventricle.
• Systole
The contraction of the cardiac muscle tissue in the ventricles is called systole.
When the ventricles contract, they force the blood from their chambers into the arteries leaving the heart.
The left ventricle empties into the aorta and the right ventricle into the pulmonary artery.
The increased pressure due to the contraction of the ventricles is called systolic pressure.
• Diastole
The relaxation of the cardiac muscle tissue in the ventricles is called diastole.
When the ventricles relax, they make room to accept the blood from the atria.
The decreased pressure due to the relaxation of the ventricles is called diastolic pressure.
At a normal heart rate, one cardiac cycle lasts for 0.8 second.
• Electrical Conduction System
The heart is composed primarily of muscle tissue. A network of nerve fibers coordinates thecontraction and relaxation of the cardiac muscle tissue to obtain an efficient, wave-like pumping action of the heart.
• Sinoatrial node (SA node)
The first part of the conduction system is the Sinoatrial node.
Without any neural stimulation, the Sinoatrial node rhythmically initiates impulses 70 to 80 times per minute.
The Sinoatrial Node (often called the SA node or sinus node) serves as the natural pacemaker for the heart.
Nestled in the upper area of the right atrium, it sends the electrical impulse that triggers each heartbeat.
The impulse spreads through the atria, prompting the cardiac muscle tissue to contract in a coordinated wave-like manner.
• Atrioventricular node (or AV node)
The impulse that originates from the sinoatrial node strikes the Atrioventricular node (or AV node) which is situated in the lower portion of the right atrium.
The atrioventricular node in turn sends an impulse through the nerve network to the ventricles, initiating the same wave-like contraction of the ventricles.
• The Right and Left Bundle Branches
The electrical network serving the ventricles leaves the atrioventricular node through the Right and Left Bundle Branches.
These nerve fibers send impulses that cause the cardiac muscle tissue to contract.
• Heart Sounds
The sounds associated with the heartbeat are due to vibrations in the tissues and blood caused by closure of the valves. Abnormal heart sounds are called murmurs.
• Heart Rate
The Sinoatrial node, acting alone, produces a constant rhythmic heart rate.
Regulating factors are reliant on the Atrioventricular node to increase or decrease the heart rate to adjust cardiac output to meet the changing needs of the body.
Most changes in the heart rate are mediated through the cardiac center in the medulla oblongata of the brain.
The center has both sympathetic and parasympathetic components that adjust the heart rate to meet the changing needs of the body.
Peripheral factors such as emotions, ion concentrations, and body temperature may affect heart rate. These are usually mediated through the cardiac center.
• THANK YOU

ansforedu87 said...

By: Ansari Ahmad (2006147079)
Fluid, Electrolyte & Acid-Base Balance (Water Balance)

We often drink for social reasons and yet in spite of this the body weight of a healthy adult on an adequate diet remains remarkably stable from day to day.
This stability indicates that the body fluid volume is staying constant - there is a dynamic steady state, in which the fluid output equals the fluid input.

Water is the most important dietary constituent. We cannot reduce our water losses from the body to less than about 1200 ml per day (the skin, respiratory, and faecal losses, and a minimum urine volume of about 400 ml per day), so survival with no water intake is only possible for a few days.

What determines how much water we need to ingest?
The answer is the concentration of the solutes in the body - the body fluid osmolality.
This normally has a value of about 285 milliosmoles/kg H2O.
If the solutes get too concentrated (if the osmolality increases), this indicates that there is insufficient water to keep them at their correct concentration.
Conversely, if the solutes are diluted (decreased osmolality), there is an excessive amount of water relative to solute.

The osmolality of the blood supplying the brain is monitored by ‘osmoreceptors’ in the hypothalamus at the base of the brain, and these play a large part in determining our thirst sensation, and in the release of the hormone ADH (antidiuretic hormone, or vasopressin) from its storage site in the posterior pituitary gland.
Water deficit leads to thirst, and to ADH release into the circulating blood. The ADH acts on the kidneys to increase renal water reabsorption. Water excess suppresses thirst and decreases ADH release.

>Water deprivation<

What happens when our water intake is inadequate?
The continuing obligatory water loss from the skin and from the lungs causes a rise in the extracellular fluid osmolality, and this causes water to move from the cells to the extracellular fluid, so that there is water deficiency, and an increased osmolality, in all of the body fluid compartments.

The increased osmolality increases ADH release (Fig. 2), and the osmolality and cellular dehydration causes the sensation of thirst.

When we are deprived of water, renal mechanisms are activated to conserve water, but, in practice, the situations in which water intake is low are often those in which losses from the lungs and skin are high (e.g. hot, dry environments).
The skin loss is ‘insensible perspiration’, and occurs because the skin is not completely waterproof.
Sweating is an additional loss (at up to 5 litres per hour), and is adjusted not to the needs of water balance, but to the needs of temperature regulation.
There is no convincing evidence that we humans can ‘train’ to manage with less water by alterations of our physiological mechanisms, although our behaviour can certainly be modified to conserve water.
For example, hard physical work produces metabolic heat, so avoiding such work reduces the need to sweat.

What are the physiological effects of water deprivation?
The first sign is the sensation of thirst.
This begins when the body fluids have decreased by 2% from the normal volume of about 40-45 litres in a 70 kg person.
when the deficit reaches 4%, the mouth and throat feel dry, and functional derangements develop — apathy, sleepiness, impatience. At 8% deficit, there is no longer any salivary secretion; the tongue feels swollen, and speech is difficult.
By the time the deficit reaches 12% (4.5-5 litres less water in the body than there should be), the victim is unable to recover without assistance, and is unable to swallow. The lethal limit of water deprivation is about 20%.

>Osmoregulation<

It is important to appreciate that people can have a water deficit even if they are drinking.
This is because there is a maximum possible urine concentration — about 1400 millosmoles per kg H2O in adults, but only about half of that value in children.
So if we ingest hypertonic solution — solutions with a higher solute concentration (osmolality) than the plasma — we may need to excrete more water to remove the solute than we took in with it.
For example, if we ingest 1 kg of sea water, of osmolality 2000 millosmoles/kg H2O, and we can produce urine with a maximum osmolality of 1400 millosmoles/kg H2O, we need 2000/1400 kg urine (i.e. 1.5 litres) to excrete the solute and we end up dehydrated in spite of the fluid ingested.
This is particularly important in infants.
Newborn infants have a maximum urine osmolality of only about 600 milliosmoles per kg H2O, so it is very easy to dehydrate them by giving them excessively concentrated drinks.

>Volume regulation<

The body fluid solute concentration (osmolality) is not the only regulator of our water intake — the body fluid volume is also important.
Indeed, sometimes volume regulation and osmoregulation may be in ‘conflict’. For example, during prolonged physical activity, sweating leads to a reduction in body fluid volume by loss of salt (NaCl) and water.
Drinking water in response to this lowers the body fluid osmotic concentration, which limits thirst.
Full restoration of the body fluid volume therefore requires replacement of the lost salt, as well as water.
..Peace..

ansforedu87 said...

By: Ansari Ahmad (2006147079)
Fluid, Electrolyte & Acid-Base Balance (Water Balance)

We often drink for social reasons and yet in spite of this the body weight of a healthy adult on an adequate diet remains remarkably stable from day to day.
This stability indicates that the body fluid volume is staying constant - there is a dynamic steady state, in which the fluid output equals the fluid input.

Water is the most important dietary constituent. We cannot reduce our water losses from the body to less than about 1200 ml per day (the skin, respiratory, and faecal losses, and a minimum urine volume of about 400 ml per day), so survival with no water intake is only possible for a few days.

What determines how much water we need to ingest?
The answer is the concentration of the solutes in the body - the body fluid osmolality.
This normally has a value of about 285 milliosmoles/kg H2O.
If the solutes get too concentrated (if the osmolality increases), this indicates that there is insufficient water to keep them at their correct concentration.
Conversely, if the solutes are diluted (decreased osmolality), there is an excessive amount of water relative to solute.

The osmolality of the blood supplying the brain is monitored by ‘osmoreceptors’ in the hypothalamus at the base of the brain, and these play a large part in determining our thirst sensation, and in the release of the hormone ADH (antidiuretic hormone, or vasopressin) from its storage site in the posterior pituitary gland.
Water deficit leads to thirst, and to ADH release into the circulating blood. The ADH acts on the kidneys to increase renal water reabsorption. Water excess suppresses thirst and decreases ADH release.

>Water deprivation<

What happens when our water intake is inadequate?
The continuing obligatory water loss from the skin and from the lungs causes a rise in the extracellular fluid osmolality, and this causes water to move from the cells to the extracellular fluid, so that there is water deficiency, and an increased osmolality, in all of the body fluid compartments.

The increased osmolality increases ADH release (Fig. 2), and the osmolality and cellular dehydration causes the sensation of thirst.

When we are deprived of water, renal mechanisms are activated to conserve water, but, in practice, the situations in which water intake is low are often those in which losses from the lungs and skin are high (e.g. hot, dry environments).
The skin loss is ‘insensible perspiration’, and occurs because the skin is not completely waterproof.
Sweating is an additional loss (at up to 5 litres per hour), and is adjusted not to the needs of water balance, but to the needs of temperature regulation.
There is no convincing evidence that we humans can ‘train’ to manage with less water by alterations of our physiological mechanisms, although our behaviour can certainly be modified to conserve water.
For example, hard physical work produces metabolic heat, so avoiding such work reduces the need to sweat.

What are the physiological effects of water deprivation?
The first sign is the sensation of thirst.
This begins when the body fluids have decreased by 2% from the normal volume of about 40-45 litres in a 70 kg person.
when the deficit reaches 4%, the mouth and throat feel dry, and functional derangements develop — apathy, sleepiness, impatience. At 8% deficit, there is no longer any salivary secretion; the tongue feels swollen, and speech is difficult.
By the time the deficit reaches 12% (4.5-5 litres less water in the body than there should be), the victim is unable to recover without assistance, and is unable to swallow. The lethal limit of water deprivation is about 20%.

>Osmoregulation<

It is important to appreciate that people can have a water deficit even if they are drinking.
This is because there is a maximum possible urine concentration — about 1400 millosmoles per kg H2O in adults, but only about half of that value in children.
So if we ingest hypertonic solution — solutions with a higher solute concentration (osmolality) than the plasma — we may need to excrete more water to remove the solute than we took in with it.
For example, if we ingest 1 kg of sea water, of osmolality 2000 millosmoles/kg H2O, and we can produce urine with a maximum osmolality of 1400 millosmoles/kg H2O, we need 2000/1400 kg urine (i.e. 1.5 litres) to excrete the solute and we end up dehydrated in spite of the fluid ingested.
This is particularly important in infants.
Newborn infants have a maximum urine osmolality of only about 600 milliosmoles per kg H2O, so it is very easy to dehydrate them by giving them excessively concentrated drinks.

>Volume regulation<

The body fluid solute concentration (osmolality) is not the only regulator of our water intake — the body fluid volume is also important.
Indeed, sometimes volume regulation and osmoregulation may be in ‘conflict’. For example, during prolonged physical activity, sweating leads to a reduction in body fluid volume by loss of salt (NaCl) and water.
Drinking water in response to this lowers the body fluid osmotic concentration, which limits thirst.
Full restoration of the body fluid volume therefore requires replacement of the lost salt, as well as water.

ansforedu87 said...

By: Ansari Ahmad (2006147079)
Fluid, Electrolyte & Acid-Base Balance (Water Balance)

We often drink for social reasons and yet in spite of this the body weight of a healthy adult on an adequate diet remains remarkably stable from day to day.
This stability indicates that the body fluid volume is staying constant - there is a dynamic steady state, in which the fluid output equals the fluid input.

Water is the most important dietary constituent. We cannot reduce our water losses from the body to less than about 1200 ml per day (the skin, respiratory, and faecal losses, and a minimum urine volume of about 400 ml per day), so survival with no water intake is only possible for a few days.

What determines how much water we need to ingest?
The answer is the concentration of the solutes in the body - the body fluid osmolality.
This normally has a value of about 285 milliosmoles/kg H2O.
If the solutes get too concentrated (if the osmolality increases), this indicates that there is insufficient water to keep them at their correct concentration.
Conversely, if the solutes are diluted (decreased osmolality), there is an excessive amount of water relative to solute.

The osmolality of the blood supplying the brain is monitored by ‘osmoreceptors’ in the hypothalamus at the base of the brain, and these play a large part in determining our thirst sensation, and in the release of the hormone ADH (antidiuretic hormone, or vasopressin) from its storage site in the posterior pituitary gland.
Water deficit leads to thirst, and to ADH release into the circulating blood. The ADH acts on the kidneys to increase renal water reabsorption. Water excess suppresses thirst and decreases ADH release.

>Water deprivation<

What happens when our water intake is inadequate?
The continuing obligatory water loss from the skin and from the lungs causes a rise in the extracellular fluid osmolality, and this causes water to move from the cells to the extracellular fluid, so that there is water deficiency, and an increased osmolality, in all of the body fluid compartments.

The increased osmolality increases ADH release (Fig. 2), and the osmolality and cellular dehydration causes the sensation of thirst.

When we are deprived of water, renal mechanisms are activated to conserve water, but, in practice, the situations in which water intake is low are often those in which losses from the lungs and skin are high (e.g. hot, dry environments).
The skin loss is ‘insensible perspiration’, and occurs because the skin is not completely waterproof.
Sweating is an additional loss (at up to 5 litres per hour), and is adjusted not to the needs of water balance, but to the needs of temperature regulation.
There is no convincing evidence that we humans can ‘train’ to manage with less water by alterations of our physiological mechanisms, although our behaviour can certainly be modified to conserve water.
For example, hard physical work produces metabolic heat, so avoiding such work reduces the need to sweat.

What are the physiological effects of water deprivation?
The first sign is the sensation of thirst.
This begins when the body fluids have decreased by 2% from the normal volume of about 40-45 litres in a 70 kg person.
when the deficit reaches 4%, the mouth and throat feel dry, and functional derangements develop — apathy, sleepiness, impatience. At 8% deficit, there is no longer any salivary secretion; the tongue feels swollen, and speech is difficult.
By the time the deficit reaches 12% (4.5-5 litres less water in the body than there should be), the victim is unable to recover without assistance, and is unable to swallow. The lethal limit of water deprivation is about 20%.

>Osmoregulation<

It is important to appreciate that people can have a water deficit even if they are drinking.
This is because there is a maximum possible urine concentration — about 1400 millosmoles per kg H2O in adults, but only about half of that value in children.
So if we ingest hypertonic solution — solutions with a higher solute concentration (osmolality) than the plasma — we may need to excrete more water to remove the solute than we took in with it.
For example, if we ingest 1 kg of sea water, of osmolality 2000 millosmoles/kg H2O, and we can produce urine with a maximum osmolality of 1400 millosmoles/kg H2O, we need 2000/1400 kg urine (i.e. 1.5 litres) to excrete the solute and we end up dehydrated in spite of the fluid ingested.
This is particularly important in infants.
Newborn infants have a maximum urine osmolality of only about 600 milliosmoles per kg H2O, so it is very easy to dehydrate them by giving them excessively concentrated drinks.

>Volume regulation<

The body fluid solute concentration (osmolality) is not the only regulator of our water intake — the body fluid volume is also important.
Indeed, sometimes volume regulation and osmoregulation may be in ‘conflict’. For example, during prolonged physical activity, sweating leads to a reduction in body fluid volume by loss of salt (NaCl) and water.
Drinking water in response to this lowers the body fluid osmotic concentration, which limits thirst.
Full restoration of the body fluid volume therefore requires replacement of the lost salt, as well as water.
..Peace..

Elda said...

TOPIC : INTRODUCTION TO BLOOD
FLOW, BLOOD PRESSURE AND
RESISTANCE
NAME : ELDA KONSAGA
MATRIX NUM : 2006139379

INTRODUCTION
Blood maintains as a suitable environment for the individual cells of the body by transporting necessary substances to and form environment.
Mechanism (process) that ensure adequate flow of blood to the tissue : Homeostatic Process
The flow of blood and factors that are control it constitute is called ‘hemodynamics.’
3 basic element in the movement of blood;
> Flow
> Pressure
> Resistance

BLOOD FLOW
The flow caused by pressure generated by the ventricle and its directly proportional to the pressure.

It can be calculated by dividing the vascular resistance into the pressure gradient.



Blood flow = the volume of blood passing a point
given period of time.
= Expressed in milliliters / liters per
minute.
= May be the blood flow to a
particular organ, or the blood flow in
the entire circulatory system.
= The total blood flow is the volume of
blood leaving the left ventricle
each minute same as cardiac input.



Generally in the body, blood flow is laminar. However, under conditions of high flow, particularly in the ascending aorta, laminar flow can be disrupted and become turbulent.

Turbulent flow also occurs in large arteries at branch points, in diseased and narrowed arteries and across stenotic heart valves. 


Disturbed blood flow may cause ischemia and even infarction of the dependent tissue supplied by the struck vessels.
Causes include:
- Thrombosis
- Atherosclerosis
- Prolonged bedrest or immobilization
- Myocardial infarction
- Atrial fibrillation
- Prosthetic cardiac valves

Effects Of Various Factor on Blood Pressure
Renal factors : the kidneys.
Kidneys play a major role in regulating arterial blood pressure by altering blood pressure.
As blood pressure (and/or blood volume) increases beyond normal, kidneys allow more water to leave the body in urine.
Since the source of this water is bloodstream, blood volume decrease, which in turn decreases blood pressure.



However, when arterial blood pressure falls, the kidneys retain body water, increasing blood volume and blood pressure rises.
Chemicals
Epinephrine : increase both heart rate and
blood pressure.
Nicotine : increases blood pressure by causing vasoconstriction.


Blood Pressure
The pressure the blood exerts against the inner walls of the blood vessel, and it is the force that keeps blood circulating continously even between heart beats.
Blood pressure results from two forces :
- As the heart as it pumps blood into the
arteries and through the circulatory
system.
- The other is the force of the arteries as
they resist the blood flow.

Blood pressure gradient.
When ventricles contract, they force blood into large, thick-walled elastic arteries that expands as the blood is pushed into them.

The pressure is high : In larger arteries and continue to drop throughout the pathway.

Arterial pressures can be measured invasively (by penetrating the skin and measuring inside the blood vessels) or non-invasively.

Measurement unit for blood pressure : - mmHg (millimeter of mercury).
For example, normal pressure can be stated as 120 over 80.


Blood Resistance
Resistance to blood flow within a vascular network is determined by:
> Size of individual vessels (length and
diameter)
> The organization of the vascular network
(series and parallel arrangements),
> Physical characteristics of the blood
(viscosity, laminar flow versus turbulent
flow)
> Extravascular mechanical forces acting
upon the vasculature


Factors that determine resistance across a heart valve are the same as described above except that length becomes insignificant because path of blood flow across a valve is extremely short compared to a blood vessel. 
Therefore, when resistance to flow is described for heart valves, the primary factors considered are radius and blood viscosity.

Changes in vessel diameter, particularly in small arteries and arterioles, enable organs to adjust their own blood flow to meet the metabolic requirements of the tissue.
Therefore, if an organ needs to adjust its blood flow (and therefore, oxygen delivery), cells surrounding these blood vessels release vasoactive substances that can either constrict or dilate the resistance vessels.



In organs such as the heart and skeletal muscle, mechanical activity (contraction and relaxation) produces compressive forces that can effectively decrease vessel diameters and increase resistance to flow during muscle contraction.

jumardi_alkhawarizmi88 said...
This comment has been removed by the author.
jumardi_alkhawarizmi88 said...

PREPARED BY:
JUMARDI ABU BAKAR
2006111277
BODY TEMPERATURE REGULATION


BODY TEMPERATURE REGULATION
 Body temperature regulation represents the balance between heat production and heat loss.
Normal human temperature
 Average oral temperature for healthy adults had been considered 37.0 °C (98.6 °F), while normal ranges are 36.1 °C (97.0 °F) to 37.8 °C (100.0 °F).

Hot condition
It is literally set higher than usual.
 37°C (98.6°F) - Normal body temperature (which varies between about 36.123-37.5°C (96.8-99.5°F)
 38°C (100.4°F) - Sweating, feeling very uncomfortable, slightly hungry.
 39°C (102.2°F) (Pyrexia) - Severe sweating, flushed and very red. Fast heart rate and breathlessness. There may be exhaustion accompanying this. Children and epileptics may be very likely to get convulsions at this point.
 40°C (104°F) - Fainting, dehydration, weakness, vomiting, headache and dizziness may occur as well as profuse sweating.
 41°C (105.8°F) - (Medical emergency) - Fainting, vomiting, severe headache, dizziness, confusion, hallucinations, delirium and drowsiness can occur. There may also be palpitations and breathlessness.
 42°C (107.6°F) - Subject may turn pale or remain flushed and red. They may become comatose, be in severe delirium, vomiting, and convulsions can occur. Blood pressure may be high or low and heart rate will be very fast.
 43°C (109.4°F) - Normally death, or there may be serious brain damage, continuous convulsions and shock. Cardio-respiratory collapse will occur.
 44°C (111.2°F) or more - Almost certainly death will occur; however, patients have been known to survive up to 46.5°C (115.7°F).[3]

COLD CONDITION
 37°C (98.6°F) - Normal body temperature (which varies between about 36-37.5°C (96.8-99.5°F)
 36°C (96.8°F) - Mild to moderate shivering (this drops this low during sleep). May be a normal body temperature.
 35°C (95.0°F) - (Hypothermia) is less than 35°C (95.0°F) - Intense shivering, numbness and bluish/grayness of the skin. There is the possibility of heart irritability.
 34°C (93.2°F) - Severe shivering, loss of movement of fingers, blueness and confusion. Some behavioural changes may take place.
 33°C (91.4°F) - Moderate to severe confusion, sleepiness, depressed reflexes, progressive loss of shivering, slow heart beat, shallow breathing. Shivering may stop. Subject may be unresponsive to certain stimuli.
 32°C (89.6°F) - (Medical emergency) Hallucinations, delirium, complete confusion, extreme sleepiness that is progressively becoming comatose. Shivering is absent (subject may even think they are hot). Reflex may be absent or very slight.
 31°C (87.8°F) - Comatose, very rarely conscious. No or slight reflexes. Very shallow breathing and slow heart rate. Possibility of serious heart rhythm problems.
 28°C (82.4°F) - Severe heart rhythm disturbances are likely and breathing may stop at any time. Patient may appear to be dead.
 24-26°C (75.2-78.8°F) or less - Death usually occurs due to irregular heart beat or respiratory arrest; however, some patients have to been known to survive with body temperatures as low as 14.2°C (57.5°F).[3]

BODY TEMPERATURE REGULATION
 Thermoregulation: The ability of an organism to keep its body temperature within certain boundaries, even when temperature surrounding is very different.
 homeostasis: Dynamic state of stability between an animal's internal environment and its external environment
 Heat stroke: Body is unable to maintain a normal temperature and it increases significantly above normal.
 Hypothermia : Body temperature decreases below normal levels
 Hyperthermia: body temperature increase up normal levels.

MECHANiSM OF HEAT EXCHANGE
 Radiation
Heat transfer from the exposed part of the body to the cooler air.
 Conduction:
Transfer of heat from warmer object to a cooler one when the two are in direct contact with each other.
 Convection
Warmer air moves away from the body via breezes
Enhances heat transfer from the body surfaces to the air because the cooler air absorb heat by conduction more rapidly than the already warmed air.
 Evaporation:
Excess body heat is carried away.

Heat production:
1. basal metabolism
2. muscular activity (shivering).
3. thyroxine and epinephrine.
4. temperature effect on cells.

Heat loss:
1. radiation.
2. conduction/convection.
3. evaporation.
HEAT PROMOTING MECHANISM
 Constriction of cutaneous blood vessels.
Activation of the sympathetic vasoconstrictor fibers serving the blood vessel of the skin causes strong vasoconstriction.
Causes: blood restricted to deep body area and largely bypasses the skin.
 Shivering
Involuntary shuddering constraction, is triggered when brains centers controlling muscle tone are activated and muscle tone reaches sufficient levels to alternately stimulate stretch receptors in antagonistic muscles.
 Increase in metabolic rate
Cold stimulates the release of epinephrine and norepinephrine by the adrenal medulla in response to sympathetic nerve stimuli, which elevates the metabolic rate and enhances heat production.
 Enhanced thyroxine release
When environmental temperatures decrease gradually, the hypothalamus of infants release thyrotropin-releasing hormone. This activates the anterior pituitary to release thyroid-stimulating hormone, which induces the thyroid to liberate larger amount of thyroid hormone to the blood to increase metabolic rate.
 Dilation of cutaneous blood vessels
As the blood vessels swells with warm blood, heat is los from the shell by radiation, conduction and convection.
 Enhanced sweeeting
If the body extremely overheated, sweet glands are strongly activated by symphatic fibers and spew out large amounts of respiration is an eficient means of ridding the body serplus heat as long as the air is dry.


 Fever
Controlled hyperthermia, macrophages and other cells release cytokines originally called pyrogens. This chemical act on hypothalamus, causing release of prostaglandins which reset the hypothalamic thermostat to a higher normal temperature.
The temperature rises until it reaches the new setting, and then is maintained at that setting until natural body defenses or antibiotics reverse the disease process, and chemical messenger called cryogens act to prevent fever from becoming excessive and reset the thermostat to a lower level.


In hot conditions
 Sweat glands under the skin secrete sweat (a fluid containing mostly water with some dissolved ions) which travels up the sweat duct, through the sweat pore and onto the surface of the skin. This causes heat loss by evaporation; however, a lot of essential water is lost.
 The hairs on the skin lie flat, preventing heat from being trapped by the layer of still air between the hairs. This is caused by tiny muscles under the surface of the skin called arrector pili muscles relaxing so that their attached hair follicles are not erect. These flat hairs increase the flow of air next to the skin increasing heat loss by convection. When environmental temperature is above core body temperature, sweating is the only physiological way for humans to lose heat.
 Arterioles Vasodilation occurs, this is the process of relaxation of smooth muscle in arteriole walls allowing increased blood flow through the artery. This redirects blood into the superficial capillaries in the skin increasing heat loss by radiation and conduction.
In cold conditions
 Sweat stops being produced.
 The minute muscles under the surface of the skin called arrector pili muscles (attached to an individual hair follicle) contract (piloerection), lifting the hair follicle upright. This makes our hairs stand on end which acts as an insulating layer, trapping heat. This is what also causes goose bumps since humans don't have very much hair and the contracted muscles can easily be seen.
 Arterioles carrying blood to superficial capillaries under the surface of the skin can shrink (constrict), thereby rerouting blood away from the skin and towards the warmer core of the body. This prevents blood from losing heat to the surroundings and also prevents the core temperature dropping further. This process is called vasoconstriction. It is impossible to prevent all heat loss from the blood, only to reduce it. In extremely cold conditions excessive vasoconstriction leads to numbness and pale skin. Frostbite only occurs when water within the cells begins to freeze, this destroys the cell causing damage.
 Muscles can also receive messages from the thermo-regulatory center of the brain (the hypothalamus) to cause shivering. This increases heat production as respiration is an exothermic reaction in muscle cells. Shivering is more effective than exercise at producing heat because the animal remains still. This means that less heat is lost to the environment via convection. There are two types of shivering: low intensity and high intensity. During low intensity shivering animals shiver constantly at a low level for months during cold conditions. During high intensity shivering animals shiver violently for a relatively short time. Both processes consume energy although high intensity shivering uses glucose as a fuel source and low intensity tends to use fats. This is why animals store up food in the winter.

Nie said...

EXNIKOL JAIKOL
2006111293

PREGNANCY & HUMAN DEVELOPMENT

Fertilization

*oocyte viable 12 - 24 after ovulation
*sperm retain fertilizing power within female reproductive tract 12 - 48 hours
*some “super sperm” viable for 72 hours
*about 5 days a month that pregnancy can occur

Sperm Transport

*acidity within the vagina is hostile to sperm & some leak from vagina or die almost immediately
*many cannot penetrate cervical mucus
*in uterus thousands are killed by leukocytes
*only a few thousand finally reach uterine tubes

Capacitation

*membranes must become fragile so that hydrolytic enzymes in their acrosomes can be released

Acrosomal Reaction

*acrosomal reaction: release of acrosomal enzymes that occurs in immediate vicinity of oocyte
*hundreds of acrosomes must rupture to break down *intercellular cement of oocyte
single sperm makes contact with oocyte

Sperm Penetration

*nucleus is pulled into oocyte cytoplasm
*only one sperm is allowed to penetrate
*Fusion of nuclear material occurs to complete fertilization

Preembryonic Development

1. Cleavage & Blastocyst Formation

*cleavage: period of rapid mitotic divisions following fertilization
*daughter cells become smaller & smaller
*results in a high surface-to-volume ratio for greater uptake of oxygen & nutrients
*blastomeres:
2 identical cells by 36 hours
4 identical cells by 60 hours
8 identical cells by 72 hours
*morula: berry-shaped
100 cell 4-5 days

Implantation

*6 days after ovulation implantation begins
*completed by 14 day

Placentation

*formation of placenta
*highly vascular
*fully functional as nutritive, respiratory, excretory, & endocrine organ by end of 2nd month of pregnancy
*some harmful substances can pass placental barriers
*teratogens: may cause severe congenital abnormalities or even fetal death
alcohol, nicotine, drugs, infections

Events of Embryonic Development

-Formation & Roles of Embryonic Membranes

*amnion: sac that becomes filled with amniotic fluid which bathes cells
*provides buoyant environment & protection against physical trauma
helps maintain temperature
*as kidneys develop urine is added to fluid
*water portion is exchanged 3 hours
*yolk sac: blood cell formation & produce gonads
*chorion: forms placenta
*allantois: constructs umbilical cord
*becomes part of bladder

-Gastrulation: Germ Layer
Formation

*Ectoderm
-all nervous tissue
-skin, hairs, sebaceous & sweat glands, & nails
-tooth enamel
-epithelium of: oral & nasal cavities, anal canal, pineal & )pituitary glands

*Mesoderm
-skeletal, smooth, & cardiac muscle
-cartilage, bone & other CT
-blood, bone marrow, lymph tissue
-ureters, kidneys, gonads

*Endoderm
-epithelium of digestive tract
-liver, pancreas
-thyroid, parathyroid, & thymus glands

Effects of Pregnancy on Mother

*Anatomical Changes
-breasts enlarge & areolae darken
-“mask of pregnancy” pigmentation of facial skin
-uterus enlarges
-lordosis
-placenta produces the hormone relaxin, that causes ligaments to relax & become flexible for child birth
-weight gain about 25 lbs

*Gastrointestinal System
-excessive salivation
-morning sickness: increase of hormones
-heartburn: esophagus & stomach is crowded
-constipation: motility of digestive tract declines

*Urinary System
-urination more frequent & sometimes uncontrollable
-uterus compresses bladder
-kidneys also have to dispose of -fetal wastes

*Respiratory System
-lung volume decreases
-nasal stuffiness

*Cardiovascular System
-total body water rises as safeguard against blood lose during birth
-blood volume increases 25 - 40 %
-blood pressure & pulse rise
-uterus presses on pelvic blood vessels, venous return from lower limbs may be impaired & result in varicose veins

Parturition

*Initiation of Labor
-last few weeks of pregnancy estrogen reaches highest levels
-myometrium becomes increasingly irritable & weak which may cause Braxton Hicks contractions or false labor
-oxytocin is released by posterior pituitary which causes expulsive contraction of true labor

Stages of Labor

*Dilation
-time from labor’s onset until cervix is fully dilated (10 cm)
-contractions begin in upper part of uterus & move downward toward vagina
-contractions 15 - 30 minutes apart & last for 10 - 30 sec.
-contractions become more vigorous & rapid
-infant’s head is forced against cervix causing it to soften & become thinner
-amniotic fluid breaks
-lasts 6-12 hours

*Expulsion
-from full dilation to delivery
-contraction every 2 - 3 minutes & lasting 1 minute
-lasts 20 minutes to 2 hours
crowning
-episiotomy may be performed to reduce tearing
-umbilical cord is clamped & cut

*Placental
-delivery of placenta within 15 minutes of birth
-important that all placental fragments be removed
-called afterbirth

EisZ_UnGuViOLeT said...
This comment has been removed by the author.
EisZ_UnGuViOLeT said...
This comment has been removed by the author.
EisZ_UnGuViOLeT said...

Patterns of Genetic Inheritance:
Multiple allele inheritance and sex linked inheritance

Multiple allele inheritance
 The gene exists in several allelic forms
 A person only has 2 of the possible alleles
 A good example is the ABO blood system
 A and B are codominant alleles
 The O alleles is recessive to both A and B therefore to have this blood type you must have 2 recessive alleles
 Based on what you know what type of blood would each of the following individuals have in a cross between Ao and Bo?

possible genotypes: phenotypes:
AB Type AB blood
Bo Type B blood
Ao Type A blood
oo Type O blood

Blood type inheritance
Phenotype A
 The lA allele is dominant to i, so inheriting either the lAi alleles or the lA lA alleles from both parents will give you type A blood.
 Surface molecule A is produced.

Phenotype B
 The lB allele is also dominant to i.
 To have type B blood, you must inherit the lB allele from one parent and either another lB allele or the i allele from the other.
 Surface molecule B is produced.


Phenotype AB
 The lA and lB alleles are codominant.
 This means that if you inherit the lA allele from one parent and the lB allele from the other, your red blood cells will produce both surface molecules and you will have type AB blood.


The ABO Blood Group
 The gene for blood type, gene l, codes for a molecule that attaches to a membrane protein found on the surface of red blood cells.
 The lA and lB alleles each code for a different molecule.
 Your immune system recognizes the red blood cells as belonging to you. If cells with a different surface molecule enter your body, your immune system will attack them.


The importance of blood typing

 Determining blood type is necessary before a person can receive a blood transfusion because the red blood cells of incompatible blood types could clump together, causing death.

Sex-linked inheritance
 Traits are controlled by genes on the sex chromosomes
 X-linked inheritance: the allele is carried on the X chromosome
 Y-linked inheritance: the allele is carried on the Y chromosome
 Most sex-linked traits are X-linked

X-linked disorders
 More often found in males than females because recessive alleles are always expressed
 Most X-linked disorders are recessive:
 Color blindness: most often characterized by red-green color blindness
 Muscular dystrophy: characterized by wasting of muscles and death by age 20
 Hemophilia: characterized by the absence of particular clotting factors that causes blood to clot very slowly or not at all.


X-linked inheritance: Color blindness
 Cross:
 XBXb x XBY
 Possible offspring:
 XBXB normal vision female
 XBXb normal vision female
 XBY normal vision male
 XbY normal vision male


Hemophilia: An X-linked disorder
 Hemophilia A is an X-linked disorder that causes a problem with blood clotting.
 About one male in every 10 000 has hemophilia, but only about one in 100 million females inherits the same disorder.
 Males inherit the allele for hemophilia on the X chromosome from their carrier mothers. One recessive allele for hemophilia will cause the disorder in males.
 Females would need two recessive alleles to inherit hemophilia.



Prepared by;
Isfazira binti Ismail
2006147049