blood overview ppt
DESCRIPTION
Medical . Educational PPT . Blood Overview . physiology of blood .TRANSCRIPT
الرحمن الله بسمالرحيم
3البقرة] :2]
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.