الرحمن الله بسمالرحيم

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The Blood

By : Aya Atef Ez El- Regal

IntroductionIntroductionBlood is composed of

- 55% Plasma

- 45% Cellular elements

(RBC’s - WBC’s - Platlets)

Physical properties of blood

1.Color : Red due to hemoglobin in RBC’s

2.pH : 7.3 - 7.4

3.Viscosity : 5 times as water causes resistance of flow

4.Specific gravity:1.060 (of plasma =1.030 & RBC’s =1.090)

5.Osmotic pressure: 5100-5500 mmHg

Function of blood

1. Act as transport medium (O2 - CO2 - absorbed food)

2. Defensive function (WBCs attack foreign organisms)

3. Homeostatic function (regulation of .water content .temperature .pressure .pH )

Blood volumeBlood volume

Blood volume = 5 liters = 80 ml/kgBlood volume = 5 liters = 80 ml/kg

(3L Plasma . 2L RBC’s)(3L Plasma . 2L RBC’s)

Blood vol. represents 80% of body weight Blood vol. represents 80% of body weight

The distribution of blood The distribution of blood

55% in veins 7% in heart55% in veins 7% in heart

15% in arteries 18% in pulmonary system15% in arteries 18% in pulmonary system

5% in capillaries5% in capillaries

The plasmaThe plasmaVolume:

3 liter = 55% of blood volume =5 % of body weight

Composition:

1.Water = 90%

2.Organic constituent = 9%

-plasma proteins = 7.1 -7.4 gm%

-others = 2%

3.Inorganic constituent =1%

Plasma proteinsPlasma proteinsAlbuminAlbumin GlobulinGlobulin fibrinogenfibrinogen prothrombinprothrombin

AmountAmount 4.2 gm%4.2 gm% 2.4 gm%2.4 gm% 0.2 gm%0.2 gm% 0.01 gm%0.01 gm%

M.WM.W 70.00070.000 150.000150.000 340.000340.000 69.00069.000

Site of Site of synthesissynthesis

liverliver 1.Liver1.Liver

2.RES2.RES

liverliver liverliver

Main Main FunctionFunction

OsmoticOsmotic

CarrierCarrier

DefensiveDefensive

CarrierCarrier

ViscosityViscosity

Clotting (I) Clotting (I)

(II) Clotting (II) Clotting factor factor

Sources of plasma protein

1. Food protein :

Proteins with high biological value rich in essential amino acids

2. Tissue proteins :

a. Reserved :

1. labile: plasma proteins stored in liver

2. dispensable: synthesized in liver during starvation

b. Fixed :

essential for cell life so it can’t be converted to plasma protein

Definition :Marked decrease in plasma proteins

Causes :1. Prolonged starvation2. Decrease of absorption3. Liver diseases : cirrhosis hepatitis 4. Kidney diseases : nephrosis5. Congenital afibrinogenemia

Effects :1.Decrease of albumin decrease the osmotic pressure edema2.Decrease of globulin decrease the immunity3.Decrease of fibrinogen & clotting factors bleeding tendency

Hypoproteinemia

Albumin / Globulin ratio

A/G ratio = 1.2 – 1.7

It decreases in case of

1.Liver diseases as hepatitis ( synthesis of albumin)

2.Kidney diseases as nephrosis ( loss of albumin)

3.Infection ( gamma globulin as a defense mechanism)

The plasmaThe plasma1.1. Obtained by Obtained by

centrifugation of blood centrifugation of blood sample after adding sample after adding anticoagulant anticoagulant

2.2. Contain all plasma Contain all plasma proteins and all clotting proteins and all clotting factorsfactors

3.3. Clot on standingClot on standing

4.4. Normal serotonin levelNormal serotonin level

The serumThe serum1.1. Obtained by Obtained by

centrifugation of clotted centrifugation of clotted blood sampleblood sample

2.2. Contains all plasma Contains all plasma proteins but no clotting proteins but no clotting factor (I & II &V & VIIIfactor (I & II &V & VIII

3.3. Not clot on standingNot clot on standing

4.4. High serotonin levelHigh serotonin level

Plasma and Plasma and serumserum

Plasma

blood

Erythrocytes

RBC’s

ErythrocytesShape:Shape: biconcave non nucleated discs biconcave non nucleated discs

Volume:Volume: 90 90

It’s center appears paler than the It’s center appears paler than the periphery due to the biconcavityperiphery due to the biconcavity

Structure:Structure:

1.1.cell membranecell membrane

2.2.submembranous cytoskeletonsubmembranous cytoskeleton

3.3.contents of RBCs a. hemoglobincontents of RBCs a. hemoglobin

b. enzymesb. enzymes

c. ionsc. ions

Sites of formation of RBC’s

2.In infant & Child- Red bone marrow of all bones

3.In adult- Red bone marrow is restricted to the central skeleton (flat bones) also proximal ends of long bones- the remaining change into yellow marrow which can be reactivated to red marrow in case of sever anemia

According to age 1.In fetus- Yolk sac : first few weeks of pregnancy- Liver &spleen : from 6 weeks to 6 month- Bone marrow : from the 6th month

Normal Erythropoiseis

Needs

HypoxiaDietaryfactors

Hormonal factors

Healthy organs

proteins minerals vitamins LiverBone

marrowKidney

Factors affecting Erythropoiesis

(erythro = RBC, poiesis = to make) = the process of RBC formation

1- hypoxia

the low levels of oxygen in the blood stimulate the secretion of a hormone called erythropoietin from kidney and liver which then travels to the red bone marrow to stimulate the marrow to begin RBC production.

2-ditary factors

A. Proteins

Proteins of high biological value

B. Minerals

1.Iron • needed for the synthesize of Hb & myoglobin• found in meat , liver and green vegetables• requirement 10 mg/day for adult male• loss in stool , sweat and exfoliated skin

-In the upper part of small intestine the ferrous combine with apotransferrin to form transferrin that is absorbed by intestinal epithelium to be stored under need

-When iron content in blood decreases it is released to be used in bone marrow to form Hb of RBCs-In liver and other tissues transferrin release its iron to combine with apoferritin to store iron in form of ferritin - When body needs iron the tissue ferritin release its iron in blood to be carried as transferrin to the body where it is needed

2.Copper•Catalyze the oxidation of ferrous iron into ferric state•Carried by plasma protein

3.Cobalt•Stimulate erythropoietin release from the kidney

C. Vitamins

1-Vitamin b12•Needed for maturation of RBCs & DNA synthesis•Present in diet as protein bound complex•Requirement is 1-2 Mg/day•Stored in liver (1-5 mg)•Deficiency of vit. B12 causes megaloblastic pernicious anemia

2-folic acid

•Is water soluble vitamin essential for maturation of RBCs & DNA synthesis•Present in green vegetables ,fruits ,liver and meat•Absorbed in small intestine and changed into active folinic acid•Deficiency causes megaloblastic anemia

3-vitamin C

•Needed for reduction of ferric to ferrous and help maturation of RBCs

4-vitamin B complex

•Needed for normal erythropoiesis

3- Hormonal factors

1. Erythropoietin hormone from kidney and liver

1. Androgens: stimulate erythropoietin production from kidney

2. Thyroid hormone: stimulates bone marrow and Stimulates general metabolism increase o2 consumption &decrease o2 supply causing hypoxia to stimulate erythropoiesis

3. Glucocorticoids: acts as thyroid

4. Pituitary hormones: as growth hormone stimulate bone marrow

1. Haemopoietic growth factors : secreted by lymphocytes stimulate bone marrow

4- Healthy organs

1-Liver •Storage of iron & vit. B12 & folic acid &copper•Formation of erythropoietin hormone•Formation of globin part of Hb•Synthesis of RBCs in fetal life•Destruction of old RBCs

2-bone marrow•Site of erythropoiesis•Irradiation, infection, toxins or tumor causes aplastic anemia

3-kidney•Formation of erythropoietin hormone•So renal failure lead to decrease erythropoietin andretention of toxic substances as urea lead to depression of bone marrow

HEMOGLOBIN

It is the principle constitute of RBCs (33%) which is a red pigment which give the blood it’s color

Structure if Hb

-Globin: 2 pairs of polypeptide chains (2 a& 2 B)

-4 Haem: each is an iron-protoporphyrin

Hb is made of 4 subunits each formed of one Haem & one globin polypeptide chain

Function of Hb

•Carriage of O2 - CO2

•Strong buffer system

Oxy HbOxy Hb Met HbMet Hb Carbamin HbCarbamin Hb Carboxy HbCarboxy Hb

normalnormal abnormalabnormal normalnormal abnormalabnormal

Carry Carry O2 Not carry Not carry O2 Carry Carry CO2 Not carry Not carry CO2

-O2 bind with fe in ferrous state

-Called oxygenation

-Strong oxidation -Strong oxidation by oxidizing by oxidizing agentagent

-Causes dusky -Causes dusky color of skincolor of skin

-CO2 attached -CO2 attached to the globin to the globin part of Hbpart of Hb

-CO attach to Fe -CO attach to Fe in high affinityin high affinity

210 times as O2210 times as O2

Affected by:Affected by:

-pH-pH

-Temperature-Temperature

-2,3DPG-2,3DPG

-Normal Met Hb -Normal Met Hb not exceed 0.5% not exceed 0.5% Due to NADH-Due to NADH-MetHb reductase MetHb reductase enzymeenzyme

-Binding to CO2 -Binding to CO2 causes decrease causes decrease of affinity of Hb of affinity of Hb to O2to O2

Part attached to Part attached to CO not carry O2CO not carry O2

Remaining partRemaining part of of

Hb not give it’sHb not give it’s O2 to tissueO2 to tissue

Reactions of HbReactions of Hb

Hemoglobin

Adult Hb (Hb A)

(Hb A2) Fetal Hb (Hb F)

Glycosylated Hb

Hb S

Types of Hemoglobin

Function of spleen

1-storage (blood reservoir):•Stores 250 ml of blood•Sympathetic stimulation add thisamount to general circulation

2-synthesis (Hemopoietic tissue ):•During intrauterine life or extrameduilary hemopoiesis

3-defensive function:•part of reticulo endothelial system

4-Destruction of old RBCs

Destruction of RBCs :

•Lifespan of RBCs = 120 days•Old RBCs removed from blood by phagocytic cells in narrow capillaries of RES (spleen) and Hb released

1- Globin: used in protein synthesis in liver

2- iron part of Haem: stored as ferritin in liver

3-protoprophyrin part of Haem: used in bile pigments (Bilirubin) which is conjugated in liver then excreted in bile

Destruction of RBCs

BloodGroups

ABO blood grouping system

According to the ABO blood typing system there are four different kinds of blood types:

A, B, AB or O .

Blood group A have A antigens on the surface

of RBCs and B antibodies in blood plasma.

Blood group B have B antigens on the surface

of RBCs and A antibodies in blood plasma.

Blood group ABhave both A and B antigens on

the surface of RBCs and no A or B antibodies in blood plasma

Blood group O have neither A or B antigens

on the surface of RBCs but both A and B antibodies in blood plasma.

Blood transfusionBlood transfusion

Universal DonorUniversal Donor Group OGroup O

– Carries no A or B Carries no A or B antigensantigens

– Packed and Packed and processed units have processed units have little antibodylittle antibody

Universal RecipientUniversal Recipient Group ABGroup AB

– Patient has no anti-Patient has no anti-A or anti-B presentA or anti-B present

– antibodies may be antibodies may be presentpresent

The Rhesus (Rh) factor

•According to presence of Rh agglutinogen on RBCs membrane

1- Rh +ve = 85 % (have D-antigen may be DD or Dd)

2- Rh –ve = 15% (no D-antigen genotype is dd)

•D-antigen is the most important Rh-antigen

•Normally the plasma doesn’t have anti D-agglutinin

• A person with Rh- blood can develop Rh antibodies in the blood plasma if he or she receives blood from a person with Rh+ blood

• whose Rh antigens can trigger the production of Rh antibodies.

•A person with Rh+ blood can receive blood from a person with Rh- blood without any problems.