ANATOMY OF BLOOD- RBCs, WBCs & Platelet

This lecture involves, anatomy of RBC, WBC and platelets. It includes detailed description of this cells, its functions and hematopoeisis in short. This lecture is prepared for BSc nursing students.

1. ANATOMY OF BLOOD BY : MS. SAILI GAUDE PRINCIPAL SHIVAM COLLEGE OF NURSING AMIRGADH

2. INTRODUCTION Combination of plasma and blood cells that circulate through the entire body Important for regulation of the body’s pH, temperature, osmotic pressure , the circulation of nutrients and removal of waste, the distribution of hormones from endocrine glands and the elimination of excess heat. Medium through which all necessary elements like nutrients and oxygen are transferred to cell and all metabolic wastes are transferred from cells. Consists of 7-8 of human body’s weight

3. Physical characteristics Characteristic Feature Color Red Amount 7-8% of total body weight Blood volume 4-5 litre (F) and 4-6 litre (M) Viscosity 3.4 to 5.4 times more than water Specific gravity 1.045 to 1.065 pH 7.35 to 7.45 Temperature 38 degree C Osmotic pressure 25 mmHg

4. COMPOSITION

5. BLOOD PLASMA

6. Blood plasma Liquid component of blood Mixture of water, sugar, fat, protein and salts 90 % water with remaining 10 % made up of ions, proteins, nutrients, wastes and dissolved gases. These ions, and proteins maintain blood pH and osmotic balance Normal range – 60 to 80 g/dl of blood Liver produces 30g of plasma protein everyday

7. FUNCTIONS OF PLASMA To transport the blood cells throughout body To transport : 1) Nutrients 2) Waste 3) Antibodies 4) Clotting proteins 5) Chemical messengers 6) Proteins To maintain body’s fluid balance To maintain osmotic pressure To maintain blood viscosity To regulate blood pressure To aid in blood coagulation Transport gases and Help in immune functions

8. PLASMA PROTEINS

9. FUNCTIONS OF PLASMA PROTEIN Important reserve supply of amino acids for cell nutrition. Carriers for other molecules Keeps blood slightly basic at a stable pH Assists in blood coagulation Govern the distribution of water between blood and tissue fluid

10. Important reserve supply of amino acids for cell nutrition Cells called macrophages in the liver, gut, spleen, lungs and lymphatic tissue can break down plasma proteins so as to release their amino acids. These amino acids are used by other cells to synthesize new products

11. Carriers for other molecules Many types of small molecules bind to specific plasma proteins and are transported from the organs that absorb these proteins to other tissues for utilization

12. Keeps blood slightly basic at a stable pH The proteins also helps to keep the blood slightly basic at a stable pH. They do this by functioning as weak bases themselves to bind excess H+ ions. By doing so, they remove excess H+ from the blood which keeps it slightly basic

13. Assists in blood coagulation The plasma proteins interact in specific ways to cause the blood to coagulate which is part of the body’s response to injury to the blood vessels. Coagulation of blood helps protect against the loss of blood and invasion by foreign micro-organisms and viruses.

14. Govern the distribution of water between blood and tissue fluid Plasma proteins governs the distribution of water between the blood and tissue fluid by producing what is known as a colloid osmotic pressure

15. TYPE OF PLASMA PROTEINS PROTEINS PERCENTAGE ALBUMIN 60% GLOBULIN 35% FIBRINOGEN 4% OTHERS 1%

16. ALBUMIN Regulates the osmotic pressure of the blood Acts as a carrier molecules for free fatty acids, some drugs and steroid hormones

17. GLOBULINS Globulins participates in the immune system as immunoglobuins Acts as transport of these proteins Transportation of hormones and minerals- thyroglobulins Plays a role for inhibition of some proteolytic enzymes like a2, macroglobulin which inhibits activity of trypsin

18. FIBRINOGENS Fibrinogens are involved in the clotting process These are responsible for coagulation of the blood

19. OTHERS Electrolytes – K,NA,CL,CA,HCO3 Gases- oxygen, carbon dioxide, nitrogen Nutrients – vitamins, minerals, glucose, amino acids and fatty acids Waste products – urea, uric acid and creatinine

20. BLOOD Cells

21. Blood cells

22. 3 types of blood cells RED BLOOD CELLS WHITE BLOOD CELLS PLATELETS Erythrocytes Leukocytes Thrombocytes

23. RED BLOOD CELLS Also called erythrocytes Made in bone marrow of bones Bi concave and disc shaped Size is smaller than other cells- 7 micrometer Biconcave and disc shaped Non nucleate cells Normal RBC count- 2.4 million

24. After completion of life span or when it becomes old then, it is removed out of the circulatory system by the specialized cells in the spleen Red blood cells, transport O2 from lungs to all respiring tissues. Prepare CO2 for transport from all respiring tissues to lungs Red colouration of the RBCs is due the pigment hemoglobin Red blood cells, contain hemoglobin , a red iron containing pigment which can carry O2 In the lungs Hb combines with O2 to form oxyhemoglobin . In other organs oxyhemoglobin splits up into hemoglobin and oxygen

25. hemoglobin Hemoglobin may be defined as a vital conjugated protein present inside the red blood cells Normal Hb % found in adult male is 14 to 16 g and 12 to 14g in female and 14 to 20 gm in baby. It is the protein molecule in red blood cells, that bear oxygen from the lungs to the body’s tissues and returns carbon dioxide from the tissues back to the lungs. HEMOGLOBIN = Haem + Globin Iron Protein

26. Haem Haem is the pigment It is an iron containing porphyrin known as iron porphyrin Ix. The porphyrin nucleus consists of 4 pyrole rings joined together by 4 methines bridges. The porphyrins are thus tetraphyroles . The pyrole rings are numbered i , ii, iii, iv Side chain – 1,3,5,8 Each group can carry 1 oxygen molecule , thus 1 hemoglobin molecule carries 4 molecules of oxygen.

27. globin Globin contains two alpha globin and two beta globin. Alpha globin is composed of 141 amino acids and the beta globin chain is composed of 146 amino acids.

28. Polypeptide chain Iron of haem is in the ferrous form. It is attached to the N of each pyrole ring and to the N of imidazole group in the associated globulin.

29. WHITE BLOOD CELLS Also known as leukocytes These are the largest blood cells. Shape- oval Contain nucleus and granules Normal count – 4000 to 11000 per mm3 Constitutes less than 1% of the blood volume.

30. They can be divided into granulocytes and agranulocytes. The former have cytoplasms that contains organelles that appear as coloured granules through light microscopy Granulocytes consists of Agranulocytes consists of Neutrophils Eosinophils Basophils Lymphocytes Monocytes

31. GRANULOCYTES

32. 1) neutrophils Constitution of WBC: 62% Cytoplasm: Granular Nucleus : Polymorphonuclear or multilobed Granules: Fine and pink in color Diameter: 10-12 Lifespan: 8hrs It secretes an enzyme that inhibits the growth of micro-organisms like bacteria and fungi

33. 2) Eosinophils Constitution of WBC: 2-4% Cytoplasm : Granular Nucleus: prominent and bilobed Granules: Large and pink- orange in color Diameter: 10 -12 Lifespan: 8-12 days It secretes enzyme that modulates allergic reaction and inflammatory reactions caused by foreign body

34. 3) Basophils Constitution of WBC : 2-4% Cytoplasm: Granular Nucleus: Pale nucleus with Bi or Tri lobe Granules: Large and blue in color Diameter : 12 -15 Lifespan : Few hours to a few days Basophils release histamine and heparin. Histamine increases the tissue blood flow as well as involved in inflammatory responses. Heparin acts as an anticoagulant

35. AGRANULOCYTES

36. 1. LYMPHOCYTES Classified as small, medium or large Medium and large lymphocytes are generally seen mainly in fibrous connective tissue and only occasionally in the circulation Constitution of WBC: 20-30% Cytoplasm : Agranular Nucleus : Eccentric Granules: Absent Diameter: 7-15

37. Types of lymphocytes : 2 B lymphocytes are concerned with humoral immunity T lymphocytes are concerned with cell mediated immunity Function- to produce antibodies in response to antigen To inhibit and destroy the invader affecting cells or tissue Functions to destroy cancer cells, cells infected with viruses and foreign invading cells. Presents antigens to activate other cells of immune system Co-ordinate actions of other immune cells, secrete antibodies and serve in immune memory

38. 2. MONOCYTES Constitution of WBC: 4-6% Cytoplasm : Agranular Nucleus: Kidney shaped Granules: Absent Diameter: 15-30 Lifespan : Hours to days Function : differentiation into macrophages, which are large phagocytic cells and digest pathogens, dead neutrophils and the debris of dead cells. Like lymphocytes they also present antigens to activate other immune cells.

39. PLATELETS Also called thrombocytes Shape of the platelet if irregular and diameter is about 2-3 micro meter In platelet also nucleus is absent that means it is anucleated . It is derived from the cytoplasm megakaryocytes in red bone marrow Average platelet count is 150-450 x 10 raised to power of 9 /L It forms by the thromboepoeitin hormone produces by kidney and liver

40. Platelets also remove out from the bone marrow by the phagocytosis Life span- 8-9 days They are derived from pinching off the cytoplasm of the Giant cell megakaryocytes in the red bone marrow Platelets are produced from very large bone marrow cells called megakaryocytes Megakaryocytes develop into giant cells, they undergo a process of fragmentation that results in the release of over 1000 platelets per megakaryocytes Platelets helps in blood coagulation to stop bleeding Platelets form a plug in case of blood loss Platelets are th smallest of the three major types of blood cells.

41. Hematopoeisis

42. Hematopoiesis Hematopoiesis is the production of all of the cellular components of blood and blood plasma It occurs within the hematopoietic system, which includes organs and tissues such as the bone marrow, liver and spleen It is the process through which the body manufactures blood cells It begins early in the development of an embryo, well before birth and continues for the life of an individual

43. Sites of hematopoiesis PHASE PERIOD SITE Mesoblastic phase First 3 months of pregnancy Yolk sac Hepatic phase 4-9months of pregnacy Liver , Spleen Myeloid phase 3 rd week after birth to puberty Bone marrow ADULTS Puberty till old age Bone marrow of ends of long bones and flat bones

44. HEIRACHY

45. STEM CELLS These are pluripotent cells (can become any cells) capable of asymmetric division and self renewal. Their division forms: 1. specific type of cell 2. stem cells required to continue its existence. A constant number of pluripotent stem cells is maintained to ensure its availability while some differentiate to become specific cells.

46. It is believed that all blood cells arise from a single type of stem cell in the bone marrow called pluripotent stem cell because it can produce all blood cell types The pluripotent stem cells proliferate and form in to granulocytes, monocytes, erythrocytes and megakaryocytes. 1. Myeloid cells : develop in bone marrow in to granulocytes, monocytes, erythrocytes and megakaryocytes. 2. Lymphoid cells: Early in their development , lymphoid cells migrate from the bone marrow to the thymus or to the lymph nodes, spleen, and other lymphoid structures, where they proliferate and differentiate.

47. PROGENITOR & PRECURSOR CELLS The pluripotent stem cells give rise to daughter cells with restricted potentials called progenitor cells or colony forming units, since they give rise to colonies of only one cell type. There 4 types of progenitors/ Colony Forming Unit : CFU – erythrocytes (CFU – E) - RBCs CFU – megakaryocytes ( CFU – Meg)- Platelets CFU- Granulocyte-monocyte (CFU – GM)- all WBCs except CFU- Lymphoid (CFU-L)- Lymphocytes

48. GROWTH FACTORS Hemopoeitic growth factors called colony stimulating factors or hematopoeitins are proteins with complex, overlapping functions in: Stimulating proliferation of immature cells Supporting differentiation of maturation cells Enhancing the functions of mature cells.

49. THE END