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![Physical Characteristics of blood
• Viscous fluid connective tissue
• Density- Heavier and thicker than water.
• Color varies from bright red[oxygen-rich] to dark red
[oxygen-poor]
• pH is 7.35–7.45 and its salt content is 0.9%.
• Temperature is 38C, slightly higher than “normal”
body temperature.
7March 19, 2017](https://image.slidesharecdn.com/5-170319085559/75/Blood-physiology-7-2048.jpg)
![RBC…
Concentration of RBC in Blood.
• In healthy person, the average number of RBCs per cubic
millimeter [(1 mm3 = 1 µl)]
• It is the most abundant human cell
• Major content of RBCs is Hb (97% )
20
Men= 5,200,000 ±300,000
Women= 4,700,000 ±300,000
March 19, 2017](https://image.slidesharecdn.com/5-170319085559/75/Blood-physiology-20-2048.jpg)
More Related Content
Blood physiology
- 1. March 19, 20171 Blood physiology For Bsc Midwifery students Baye Dagnew (MSc) GCMHS, 2016/17 Email-bayedagnew7@gmail.com
- 2. Objectives At the endof this session, students should be able to: • Mention major functions of blood • Describe components of blood • Discuss on how blood cells are produced and developed • Describe blood grouping and transfusion 2March 19, 2017
- 3. Brain storm Question: Whyblood is red? Answer: because it contains hemoglobin which is iron rich pigment. Question: What does hemoglobin do? Answer: Hemoglobin picks up the oxygen molecules and drops off CO2 Question: What do platelets do? Answer: Platelets clot the blood during injury of blood vessels 3March 19, 2017
- 4. Introduction to blood •Blood is the only fluid circulating connective tissue. • Hematology: study of blood and blood related disorders • Blood is sometimes referred to as “the river of life,” – Blood is pumped from heart through blood vessels collectively known as circulatory system. 4March 19, 2017
- 5. Introduction to blood… •Infants & children have comparably lower volumes of blood, proportionate to their smaller size. • Volume of blood in an individual fluctuates. – During dehydration, for example while running a marathon, blood volume decreases. – Blood volume increases in circumstances such as pregnancy, when the mother’s blood needs to carry extra oxygen and nutrients to the baby. March 19, 2017 5
- 6. Introduction to blood… •Blood leaves heart via arteries that branch repeatedly until they become capillaries. – O2 & nutrients diffuse across capillary walls & enter tissues – CO2 & wastes move from tissues into the blood • O2 deficient blood leaves capillaries and flows via veins to heart. • This blood flows to lungs where it releases CO2 & picks up O2 • The oxygen rich blood returns to heart. March 19, 2017 6
- 7. Physical Characteristics ofblood • Viscous fluid connective tissue • Density- Heavier and thicker than water. • Color varies from bright red[oxygen-rich] to dark red [oxygen-poor] • pH is 7.35–7.45 and its salt content is 0.9%. • Temperature is 38C, slightly higher than “normal” body temperature. 7March 19, 2017
- 8. How much bloodis in the human body? • In average person blood accounts for approximately 8% of body weight • So, average person of 70kg will have 8×70 100 =5.4L of blood volume • Average volume of blood is 5–6 L for males, and 4–5 L for females 8March 19, 2017
- 9. Why blood volumeis higher in males than females ? Possible reasons: 1. Androgen- it stimulates RBC production, and men have higher androgen levels than women; 2. Menstruation- women of reproductive age have periodic menstrual losses 3. Body fat- Hematocrit is inversely proportional to percent body fat, which is higher in women than in men. March 19, 2017 9
- 10. Functions of Blood 1.Distribution Blood transports: a) O2 from lungs and nutrients from GIT b) Metabolic wastes from cells to lungs and kidneys for elimination. c) Hormones from endocrine glands to target organs. 10March 19, 2017
- 11. Functions of Blood… 2.Regulation Blood maintains: – Body temperature by absorbing and distributing heat – Normal pH in body tissues using buffer systems – Adequate fluid volume in the circulatory system 3. Protection • Blood prevents blood loss by: – Activating plasma proteins and platelets • Blood prevents infection by: – Synthesizing and utilizing antibodies – Activating WBCs to defend body against foreign invaders 11March 19, 2017
- 12. Blood Components Centrifugation isused to separate blood cells and plasma. Three layers formed after centrifugation 1. Upper suspension: – Plasma (55%) 2. Middle layer – Called Buffy coat – WBC and Platelets 3. Lower portion : – Reddish mass of RBC settled at bottom of test tube. – ~45% March 19, 2017 12 Withdraw blood and place in tube 1 2 Centrifuge Plasma (55% of whole blood) For med ele men ts Buffy coat: leukocyctes and platelets (<1% of whole blood) Erythrocytes (45% of whole blood)
- 13. PLASMA • Liquid portion,nonliving part of blood. • It is intravascular component of ECF • Blood plasma is composed of 1. Water: (~90%) 2. Organic constituents : (~9%) , mainly plasma proteins 3. Inorganic constituents: • electrolytes: (~1%) 4. Respiratory gases: o2 and C o2 13March 19, 2017
- 14. Principal plasma proteins •Total principal plasma protein is about 6-8g/dl, aver=7 g/dl • There are 3 principal plasma proteins – Albumin=4 g/dl – Globulin=2.7 g/dl – Fibrinogen=0.3 g/dl • Plasma proteins are synthesized by hepatocytes, lymphocytes, platelets and endothelial cells 14March 19, 2017
- 15. Functions of plasmaproteins 1. Maintaining colloid osmotic balance (albumins) 2. Transport of materials through blood (such as water, blood cells ,products of digestion and hormones) 3. Antibodies (e.g. gamma globulins, immunoglobulin) 5. Clotting factors (e.g. fibrinogen) 6. Helps to regulate body temperature 15March 19, 2017
- 16. Hematopoiesis • Production ofblood cells is called Hematopoiesis or Hemopoiesis. • Blood cells begin their lives in bone marrow from single type of cell called pluripotential hematopoietic stem cell (PHSC) • The intermediate stage cells become committed to a particular line of cells called committed stem cells • Different committed stem cells will produce colonies of specific types of blood cells. E.g. A committed stem cell that produces erythrocytes is called a colony-forming unit–erythrocyte(CFU-E) 16March 19, 2017
- 17. Figure-- Formation ofthe multiple different blood cells from the original pluripotent hematopoietic stem cell in the bone marrow. 17March 19, 2017
- 18. Haematopoiesis regulating factors •Hemopoiesis is chemically regulated by – Colony stimulating factors: GM-CSF,, M-CSF – Interleukines (eg. IL-3) – Platelet derived growth factor (PDGF) – Thrombopoietic stimulating factor (TSF) – Erythropoietin, GH, thyroid hormones (T3/T4), androgen (Testosterone) 18March 19, 2017
- 19. Red blood cells(erythrocytes) Shape and Size of RBC • Greek erythros for "red" and kytos for "hollow vessel", with -cyte translated as "cell" in modern usage). • Normal RBCs are annucleate, biconcave disks • Have no mitochondria • ATP is generated anaerobically , so erythrocytes do not consume O2 they transport. • Filled with hemoglobin (Hb), a protein that functions in gas transport. • Plasma membrane of RBCs is comprised of flexible proteins – Allow them to change shape as necessary 19March 19, 2017
- 20. RBC… Concentration of RBCin Blood. • In healthy person, the average number of RBCs per cubic millimeter [(1 mm3 = 1 µl)] • It is the most abundant human cell • Major content of RBCs is Hb (97% ) 20 Men= 5,200,000 ±300,000 Women= 4,700,000 ±300,000 March 19, 2017
- 21. RBC…H • The percent(%) volume of packed RBC’s from whole blood is called hematocrit (Hct) – It accounts about; • 42-48% (Males ), 38-43% (Females) – Hct increases in dehydration – Thus knowing Hct value is important in clinical practices to diagnose diseases. • Hemoglobin: Hb = 1/3 Hct – Red protein containing iron, responsible for O2 transport 21March 19, 2017
- 22. Erythropoiesis • Process ofRBC production • In early weeks of embryonic life primitive, nucleated RBCs are produced in the yolk sac. • During middle trimester of gestation – The liver is the main organ for production of RBCs – Spleen and lymph nodes are also involved. • Starting from last month of gestation onwards and after birth RBCs are produced exclusively in red bone marrow. 22March 19, 2017
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- 24. Regulation of erythropoiesis •Erythropoiesis is hormonally controlled. • Hormones accelerating erythropoiesis: – Erythropoietin from Juxta Glomerular( JG) -cells and hepatocytes. – GH, T3/T4, Androgens – Intrinsic factor (IF) from parietal cells of stomach • Liver plays a critical role in RBC formation as site of globin synthesis, storage area of iron and vit-B12 24March 19, 2017
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- 26. Hemoglobin (Hb) • Normalconcentration; 15 g/dl in Males and 14 g/dl in Females • Composed of proteins called heme and globin • Hb reversibly binds with oxygen and most oxygen in blood is transported in combination with Hb • Oxyhemoglobin: – hemoglobin bound to oxygen • Deoxyhemoglobin –Hb after oxygen diffuses into tissues • Carbaminohemoglobin – Hb bound to CO2 • Carboxyhemoglobin or carbon monoxyhemoglobin is a compound of Hb with CO. 26March 19, 2017
- 27. Anemia • Deficiency ofHb in blood, which can be caused by either too few RBCs or too little Hb in the cells. Types of Anemia 1. Deficiency anemia: caused by deficiency of vit-B12 , folic acid, Iron, proteins 2. Aplastic anemia: depression of bone marrow due to irradiation, drugs and leukemia 3. Hemolytic anemia: prematurely ruptured erythrocytes or formation of fragile RBCs due to sickle cell, transfusion reaction, snake venoms, malaria, erythroblastosis fetalis 4. Bleeding (blood loss anemia or hemorrhagic anemia): result of acute or chronic loss of blood 27March 19, 2017
- 28. Polycythemia: ↑RBCs count> 6 million/mm3 Or a hematocrit of >55%. Causes 1. Chronic hypoxia: -High altitude -Heart failure -Respiratory failure 2. Primary over activity of bone marrow • Physiologic polycythemia - A common type of 20 polycythemia, occurs in natives who live at high altitudes, where the atmospheric O2 is very low. Management- phlebotomy 28March 19, 2017
- 29. Leukocytes (white bloodcells) • Normal WBC count: 5,000 – 11,000/mm3 Average:7000/mm3 • Leukopenia: ↓in WBC count • Leukocytosis: ↑in WBC count Function: defense/protection against disease 29March 19, 2017
- 30. Types of WBCs Granularleukocytes • Has granules in staining – Eosinophils – Basophils – Neutrophils Agranular leukocytes • Lacks granule in staining – Monocytes – Lymphocytes 30 NB: granular vs. agranular “Every Boy Needs Mommies Love!” March 19, 2017
- 31. WBC differential count 1.Neutrophils: 50-74 ( 62%, 3000-7000/mm3 2. Lymphocytes: 20-40% (30%), 1500-3500/mm3 3. Monocytes: 2-8% (5.3%), 100-700/mm3 4. Eosinophils: 1-4% (2.3%), 100-440/mm3 5. Basophils: 0.3-0.5% (0.4%), 20-50/mm3 Relative Quantities- mnemonics –“Never Let Monkeys Eat Bananas!”( descending order in abundance) 31March 19, 2017
- 32. WBCs… Neutrophils – The mostabundant WBCs – Have multi-lobed nuclei (PMN) – Phagocytic cells (ingest bacteria) Eosinophils – Increase in number during parasitic infection (eosinophilia) – Produce hydrolytic enzymes to kill big parasites Monocytes – They are highly phagocytic cells – They are the largest WBCs – They leave the circulation, enter tissue, and differentiate into macrophages 32March 19, 2017
- 33. The tissue macrophagesystem (reticulo-endothelial system) Monocytes are formed in the bone marrow Enter the circulation Leave the circulation & enter the tissue, ↑size, ↑lysosomal activities Become tissue macrophages Lungs Skin Liver Brain Bone Spleen, Alveolar Histocytic Kupffer Microglial Osteoclasts lymph nodes Macrophages cells cells cells Reticular cells 33March 19, 2017
- 34. Lymphocytes • They aremajor soldiers in immune system battles. • Most lymphocytes continually move among lymphoid tissues, lymph, & blood, spending only a few hours at a time in blood. Thus, only a small proportion of the total lymphocytes are present in the blood at any given time. • Three main types of lymphocytes are B cells, T cells, & natural killer (NK) cells. • B cells are particularly effective in destroying bacteria & inactivating their toxins. 34March 19, 2017
- 35. Lymphocytes… • T cellsattack viruses, fungi, transplanted cells, cancer cells, & some bacteria, and are responsible for transfusion reactions, allergies, & the rejection of transplanted organs. • Immune responses carried out by both B cells & T cells help combat infection & provide protection against some diseases. • Natural killer cells attack a wide variety of infectious microbes & certain spontaneously arising tumor cells. 35March 19, 2017
- 36. Lymphocytes… • B-cells thatbind with an antigen will subsequently differentiate into Plasma cells & Memory cells Plasma cells - begin to produce antibodies (up to 2,000 per second) Memory cells - remain dormant until a person is again exposed to the same antigen 36March 19, 2017
- 37. Platelets (thrombocytes) Don’thave nuclei Have contractile proteins (actin and myosin) Normal platelet count: • 150,000 – 300,000/mm3 (Av= 250,000/mm3) • Thrombocytopenia: low number of platelets • Thrombocytosis: an increase in the number of platelets • Thrombasthenia: a decrease in function of platelets Function of platelets 1. Synthesize prostaglandins, fibrin stabilizing factor, serotonin and other chemicals. 2. Clotting mechanism by forming temporary plug that helps seal breaks in blood vessels 37March 19, 2017
- 38. Genesis of Platelets(thrombocytopoisis) 38March 19, 2017
- 39. Hemostasis • A seriesof reactions designed for stoppage of bleeding • During hemostasis, three phases occur in rapid sequence 1. Vascular spasm 2. Platelet plug formation 3. Coagulation (blood clotting) • Blood usually clots within 3 to 6 minutes 39March 19, 2017
- 40. 1. Vascular spasm •Local vasoconstriction of ruptured blood vessel that is caused by: Reflex sympathetic discharge (pain nerve impulses) Local myogenic contraction of vascular wall Importance:- blood flow is reduced. N.B- for smaller vessels, constriction is the result of thromboxane A2 released from platelets. 40March 19, 2017
- 41. 2. Platelet PlugFormation • Is very effective in preventing blood loss in small vessels. – Can stop blood loss completely if hole is not too large. • Their granules contain chemicals (clotting factors, ADP, ATP, Ca2+ & serotonin) those promote blood clotting. • Normally, platelets do not stick to each other or to endothelial lining of blood vessels • Platelets have a short life span, just 5 to 9 days. • Aged & dead platelets are removed by fixed macrophages in spleen & liver. 41March 19, 2017
- 42. Platelet Plug Formation… •Upon damage to blood vessel endothelium (which exposes collagen) platelets: – Stick to exposed collagen fibers and form platelet plug – Release serotonin and ADP, which attract additional platelets • Platelet plug is limited to the immediate area of injury 42March 19, 2017
- 43. 3. Coagulation • Setof reactions whereby blood is transformed from liquid to gel (clot). • It is slow but has long lasting effect • Formed primarily of fibrin threads but also blood cells , platelets. • Coagulation follows intrinsic and extrinsic pathways • Vitamin-K: used for synthesis of clotting factors • Blood clotting factors are produced by Liver, Platelets and endothelial cells 43March 19, 2017
- 44. Stages of BloodCoagulation • Coagulation undergoes three steps of reactions: 1. Formation of Prothrombin activators through – The intrinsic pathway – The extrinsic pathways 2. Conversion of Prothrombin into thrombin by action of Prothrombin activators (prothrombinase) 3. Conversion of fibrinogen into fibrin thread by action of thrombin 44March 19, 2017
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- 46. Human blood groups •Grouping depends on presence of antigens, agglutinogens on surface of RBCs • RBCs contain glycoproteins on their surface with antigenic effect • Major blood groups are ABO blood group and Rh system Importance of Knowing Blood groups: 1. Very essential medically, socially & Judicially. • Socially: being member of blood donor's club • Judicially: to resolve medicolegal cases 2. Among the couple helps to prevent complications due to Rh incompatibility & save child from hemolysis. 46March 19, 2017
- 47. ABO Blood Group •Based on ± of two agglutinogen (A and B), ABO blood grouping can be classified into 4 types 1. Type-A: antigen A is present on RBC. 2. Type–B: antigen B on RBCs. 3. Type–AB: both A & B exist 4. Type–O: neither agglutinogen A nor B are present. • Most Ethiopians have group “o” blood O= 47%, A= 28%, B= 20%, AB= 5%, Rh+= 97% 47March 19, 2017
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- 50. Rh Factor Firstworked out on Rhesus monkey to hence Rh-system The presence of agglutinogen D on RBCs: Rh+ Missing agglutinogen D on RBCs: Rh- Agglutinin (anti-D antibodies) are not normally present in serum but produced 20 to exposure of Rh- blood to Rh+ blood (antigen-D) NB- Serum is blood plasma without fibrinogen (clotting proteins) 50March 19, 2017
- 51. Rh Factor… Normally, bloodplasma does not contain anti-Rh antibodies. If Rh- person receives Rh+ blood transfusion, immune system starts to make anti-Rh antibodies that will remain in blood. If second transfusion of Rh+ blood is given later, previously formed anti-Rh antibodies will cause agglutination & hemolysis of RBCs in donated blood 51March 19, 2017
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- 53. Erythroblastosis Fetalis Themost common problem with Rh incompatibility, hemolytic disease of newborn (HDNB), may arise during pregnancy. Occurs when Rh- mother marries Rh+ father and conceives Rh+ fetus During delivery, there could be leakage of Rh+ blood from fetus to circulation of mother. Rh+ blood induces production of anti-D antibodies in the circulation of mother. During 2nd conception of Rh+ fetus, anti-D antibodies cross the placenta and attack RBCs of fetus 53March 19, 2017
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- 56. Blood transfusion Transfusionis transfer of whole blood or blood components (RBCs only or blood plasma only) into bloodstream or directly into red bone marrow. Transfusion is most often given to alleviate anemia, blood volume (e.g., after severe hemorrhage). Whole blood transfusion is used: – When blood loss is substantial – In treating thrombocytopenia • Packed red cells (cells with plasma removed) are used to treat anemia 56March 19, 2017
- 57. Blood transfusion compatibility 57 ABis universal recipient O is universal donor March 19, 2017
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Editor's Notes
- #22 haemoglobin /%hi;m@"gl@UbIn/ (US hemoglobin) · n. Biochemistry a red protein containing iron, responsible for transporting oxygen in the blood of vertebrates. – ORIGIN C19: a contracted form of haematoglobulin, in the same sense.