BLOOD .ps



BLOOD.

Composition of Blood:-

Blood is one of the body fluid compartment ,it form 8% of the total body wieght it is formed of two element :

1-Plasma: which is fluid part ,represent 55%of total blood volume .

2-Formed elements:which is formed of cell(red ,white ,platelets),form45%of blood volume .

Function:-

1-blood is acomplex transport medium ,formed of 2processes picking up and delivery ,transporting oxygen ,hormones ,enzymes buffers and biochemical substances.

2-Blood plays amajor role in the heat iegulating system.

Blood volume :-

In healthy young female it is about 4-5 litters ,in male it is about 5-6 litters .

PLASMA:is aclear straw colored fluid ,formed mainly of water (90%)and the rest 10%is formed of solutes .

NOTE: hematocrite value is the precentage of formed elements to the total blood volume ,it is used to describe the volume percent of red blood cells in whole blood .

*In man it is 45% (+-7% normalrange).

*In woman it is 42% (+-5%normal range) .

Plasma proteins : constitute 6-8% of the plasma ,they are albumin globulin and fibrinogen .

Formed elements of blood :-

1-red blood cells( R B Cs)*each cell is round ,biconcave surfaces ,has no nucleus ,measures 7.5%micron ,the cell has no cellular organells (ribosomes , mitochondria …ect) .-One third (1/3/of the cellvolume is formed of hemoglobin ,each cellhas many stretchable fibers of special type of protein ,make the cell flexable ,in man the number of RBCsis about 5.5million /mm3*in woman it is 4.8million /mm3,the differences between male and female hemoglobin concentration is related to the stimulating effect of testosterone .

Function :1-Transport of oxygen (O2) and carbon dioxide(CO2) the main factor is the presence of hemoglobin.

2-RBC contain of enzyme, carbonic anhydrase ,which catalyzes the formation of carbonic acid CO2+H2O---H2CO3.

Hemoglobin (HB):represent 95%of the dry body weigh of each RBCs,each hemoglobin moleule is formed of protein called globin and uiron atoms ,each molecule of hemoglobin will bind with carbon dioxide to form carbaminohe moglobin.

NOTE: In man each 100ml of blood contains 12-14gram.

Anemia means each 100ml of blood contain lessthan 10gram hemoglobin .

Formation of RBCpolys (erythropoiesis)

Thesite of erythropoiesis is the red bone marrow ,the mother cell (stem cell) is called hemocytoblast ,it divides by mitosis to be proerythroblast ,by more mitosis becomes basophilic erythroblast to be called polychromic erythroblast is this stage the cell forms hemoglobin ,the cell will loose its nucleus and bacomes reticulocyte,which loosesits fine reticulum to matune into erythrocyte.

Note :the entire maturation process requires about 4days*every minute of every day of our adult life about 100millions RBCs are formed to replace an aqual number destroyed cells during the same time .*The main stimulant is ahormone known as erythropoietin that secreted from the liver in anormal conditions ,but if tissue anoxia occurs ,kidneys willsecrete more erythropoietin ,that stimulates the red bone marrow *so the relation between erythropotietin and tissue oxygen is anegative feedback mechanism .

*For proper RBC formation ,blood must supply the bone marrow with vitamin B12,iron and aminoacids ,cobalty and cooper and acting as catalysts ,Intrinsic factor(from the stomach )stimulantes vitamin B12absorption.

Destruction of RBCs: The average life span of acirculating RBCsis 105-120days old RBCswill be fragmented in the capillaries .

-The macrophages in the liver and spleen capillaries will engulf ,this willrelase the 3components .

-Iron will return to the bone marrow ,for resynthesis of new hemoglobin .

-Bilirubin will be transported the liver to secrete it the

Globulin (aminoacid) will be used as energy source .

White Blood Cell (W B Cs)

There are 5 types of WBC,classified in 2 group according to the presence of the cytoplasmic granules .

1-Granulocytes ;the cytoplasm has granules ,they include A)Neutrophils {polymorphonuclear }the granules are small and numerous .*One nucleus has 2-3lobes .

*Highly mobile cell.

*Represents 65%of total WBCs.

*Active phagocyte cell. *can migrate outside the blood vessels . *12-15um in diameter .

*Its life span in hour up to 3days .

B)Basophil

*12-14um in diameter .

*Spherical shape .

*Nucleus has two lobes of s shape .

*The cytoplasm has large granules .

*Represent 0.5-1%of the total WBCs.

*Its age ;hours to 3 days .

Function s ;1-secrstion of heparin(anticoagulant factor).

2-contains histamine which is important in inflammatory process .

C)Eosinophil

*10-12um in diameter .

*The cytoplasm contains orange colored granules .

*The nucles is formed of 2lobes ,connected by narrowsegment .

*Its age is 10-12 days

*Represent 2-5%of total count .

Function :1-phagocytosis of chmical and big pathological agent of protozoa ,parasite .

relasing anti inflammatory substancess contain allergy condition .2)Agranulocytes ;the cytoplasm contain no granules ,there are 2 types;A)Lymphocyte:*the smallest WBCs, 6-8um in diameter .*one big round nucleus .*there are two type of lymphocytes ,Bcelland T cell.*scanty cytoplasm .*amount 25%of WBCs.

Function :B lymphocyte is important in production of antibodies against specific antigens (Humoral immunity )

2- T lymphocyte is related totissue immunity .

B)Monocytes ;The largest WBCs12-17 um in dameter .

-Highty phagocytic cell ,can move out blood vessel .

-Nucleus is kidney shape .

-Age months .

-Highly mobile cell .

White Blood cell Numbers :

Cubic millimeter contain normally 5000-11000 leukocytes,leukopenia; mean that the total count is lessthat 5000mm3 and leukocytosis mean the total count is more than 11000mm3.

Note:the differential count is the percentage count of each type of white blood cells .

The typical differential count is :-Neutrophils 65% .

-Basophils 1%

-Moocytes 6% .

-Eosinophilis 3%

-Lymphocytes 25%

Platelets :those are small 2-4 um in diameter colorless ,and irregular sphinclle or oval shaped .

Count ;in normall adults its count ranges 150000-350000mm3 with average 250000/mm3in both male and female .

Function ;platelets have the property of agglutination adhesiveness and aggregation ,so the main functions are :1-hemostasis it meanstoppage of blood flow within 1-5 seconds after blood vessel injury ,platelets will adhere to damaged area forming platelet plug .

2-BlOOD CLoTTING;

formation and life span of platelats ;

plateletes are formed in red bone marrow ,lungs and to less extent in the spleen by fragmentation of alarge cell , called megakaryocytes which is 40-100um .

*Life span is about 7 days .

Coagulation Disorders

Teo main group –those that result in excessive bleeding and those that produce abnormal blood clotting ,because liver plays an important role in the synthesis of various plasma proteins ,such as prothrombin ,it is not surprisingthat liver diseases are often accompanied by atendency to bleed .Also ,bile salts form the liver are necessary for the efficient absorbingof vitamin K from the intestine and this vitamin is essential for the synthesis of prothrombin .as wellas coagulation factor vII ,Ixand X .if the liver fails to produce enough bile ,or if the bile ducts become obstructed ,avitamin k deficiency is likely to develop and the ability to form blood clots may be diminished .for this reason ,vitamin k is often administered to patients with liver diseases or bile ducts obstruction before they are treated surgically .

HEMMOPHIlIa

Is ahereditary disease that appears almost exclusively in male .Hemophilia lack ablood factor that is necessary for coagulation .consequently ,they typically experience repeated episodes of serious bleeding .

There are several types of hemophilia ,and each is caused by the lack of adifferent blood factor .however the symptoms of these condition are so similar that they are difficult to distinguish .in addition to the tendency tohemorrhage severely following minor injuries ,hemophilia is characterized by frequent nosebleeds ,large intramuscular hematomas ,blood in the urine (hematuria) and sever pain and disability caused by bleeding into joints and body cavities .

Treament for hemophilia may involve applying pressure or packing accessible bleeding sites in an effort to control blood loss.Also, transfusion of fresh plasma ,fresh frozen plasma ,or plasma concentrates (cryoprecipitates) that contain the missing blood factor 9most commonly factor VIIIc) are often used .

Certain drugs including aspirin ,ibuprofin and penicillin ,inhibit platelet activity .Consequently ,prolonged use of such drug is sometimes associated with atendency to bruise easily or to bleed excessively following injuries men-struation or dental work .

Leukemia

Leukemia is a form of cancer charactrized by an uncontrolled production of specific type of leukocytes .There are two major type of the leukemia .Mye;oid leukemia result from an abnprmal production of granulocytes by the red bone marrow ,while Lymphoid leukemia is accompained by increased formation of lymphocytes from lymph nodes .In both type ,the cell produced usually fail to mature into functional cell .Thus ,even though large numbers of neutrophils may be formed in myeloid leukemia ,these immature cell have little ability to phagocytize bacteria ,and the patient has alowered resistance to infection

Eventually ,the cell responsible for the overproduction of leukocytes tend to spread (metastasize) from the bone marrow or lymph node to other parts and as aresult white blood cellare produced abnormally in tissues throughout the body .As with other form of cancer,the leukemic cell finally appear in such great numbers that they crowd out the normal ,functioning cell ,for example leukemic cell originating in red bone marrow may invade other regions of the bone ,weakening its structure and stimulating pain receptors .Also as the normal red marrow is crowded out ,the patient is likely to become anemic and develo adeficiency of blood platelets (thrombocytopenia).

The lack of platelets is usually reflected in an increasing tendency to bleed .

Leukemias are also classified as either acute or chronic .An acute condition appears suddenly ,the symptoms progress rapidly ,and death occurs in afew months if the condition is untreated .Chronic form begin more slowly and may remain undetected for many months .without treatment ,life expectancy is about three year .The greatest success is treatment has been achieved with acute lymphoid leukemia,which is the most common cancerous condition in children .This treatment ussually involves counteracting the side effects of the condition ,such as anemia ,hemorrhaging and increased susceptibility to infection ,as well as administering chemotherapeutic drug .

Although acute lymphoid leukemia may occur at any age ,the chronic form usually occurs after fifty years of age .Acute myeloid leukemia also may occur at any age ,but it is more frequent in adults; chronic myeloid leukemia is primarily adisease of adults between twenty and fifty years of age .

Human immunodeficiency virus (HIV)

Acquired immunodeficiency syndrome (AIDS) virus is called HIV virus types 1&2 .

These virus have affinity to helper T lymphocytes that play an important role in regulating the immune system .

Destruction of helper T cell leads to development of AIDS renering the patient susceptible to awide variety of infection caused by opportunistic microorganisms like viruses ,protozoa ,fungi and bacteria . Pacient suffering from AIDS also develop various malignancies most notably kaposis sarcoma and lymphomas .

Mode of infection :In Europe and north America HIV infection is most commonly transmitted by asexual intercouurse amongst homosexual males ,but it can also be transmitted heterosexually and by blood transfusion ,drug addiction and transplacentally .

Clinical picture :1-Intitial infection with HIV is usually subclinical.

2- The large majority , however remain symptom free during the incubation period which extend from 1-10years .

3-After the Ipabout 80% of patients will develop one of the following syndroms :a-AIDS is associated with depletion of T4 lymphocytes ,serious opportunistic infection in lungs ,skin ,Git &GUT caused bypneumocystis carnii ,toxoplasma gondia ,candidal fungus ,some bacteria and viruses .

4-kaposis sarcoma without 10 years of infection .

5- Persistence of generalized lymphadenopathy .

6- Brain involvement :dementia ,psychosis or encephalitis .

*Management :-

1-No specific therapy ,but supportive measures and treatment of opportunistic infections .

2-Modification of sexual practices particularly with regard to adultery and anal intercourse .

3-Screening of donated blood before use.

4-Counseling of antibody positive persons .

5-Taking care regarding the medical staff in contact with patient or suspected blood .

6-Don’t forget the Quran direction that says

"و لا تقربوا الزنا "

7-To encourage marriage .

Hepatitis Viruses

These include three type different subgroups known as hepatitis A virus , hepatitis B virus ,and non-A non-Bhepatitis agents .

Hepatitis A(RNA):is commonly known both as epidemic or infectious hepatitis because of its mode of transmission ,outbreaks are frequuently asssociated with summer camps, military barracks, households and institutions .The usual mode of transmission is by the fecal oral route , but transmission in water ,food ,and milk is the source of commone epidemics.

Incupation period is 15-40 days .

Hepatitis B(DNA):-

Formerly known as serum hepatitis its more frequently transmitted in blood ,blood products ,or on blood contaminated ,whole blood ,menstrual blood ,plasma ,hypodermic needles ,scalpes ,dental instruments , tooth brushes ,razors ,and blood contaminated towels have all been identified in transmission of HBV.

Iiincubation period is 1-6 months.

*Clinical picture;the IP of HBV is 1-6 months, the symptoms of HBV closely resemble those found in hepatitis caused by HBV including ; headache ,fever ,chills with general weakness and jaundice , however chronic persistent cases of HBV can develop .Mortality

rate is 5-20%.

Vaccine is given at birthday then at the end of the first and sixth months respectively ...

3-NANB hepatitis; is aform of the disease recently discovered among individuals who had received trasfusions with blood that was carefully screened for the presence of HBV.

This liver infection closely resembles HBV both clinically and epidemiologically .

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