This PPT is Second part of Hematology and covers the different concepts in Hematology. This includes functions of blood, components of blood, formation of blood cells, functions of RBC, WBC and Platelets, Eryhropoiesis, leucopoiesis and Synthesis of hemoglobin

2. BLOOD
• Liquid connective tissue
• Composed of liquid extracellular matrix called blood plasma
that dissolves and suspends various cell and cell fragments.
Jegan

3. 1. Transportation
2. Regulation
3. Protection
FUNCTIONS OF BLOOD
Jegan

4. TRANSPORTATION
• Blood transports oxygen from lungs to the cells of the body and
• Carbon dioxide from the body cells to the lungs for exhalation
• Carries nutrients from GIT to body cells
• Hormones from endocrine glands to body cells
• It also transports heat and waste to organs for elimination from body
Jegan

5. REGULATION
• Blood helps to regulate body pH
• It also regulates body temperature
Jegan

6. PROTECTION
• Blood can clot which protects against its excessive loss after
injury
• WBC protect against disease by carrying phagocytosis
Jegan

7. PHYSICAL CHARACTERISTICS OF BLOOD
• Blood is denser than water
• It is slightly sticky
• Temperature of blood is 38
o
C
• Slightly alkaline pH: 7.35-7.45
• Color of blood varies with oxygen content
 High oxygen content- bright red
 Low oxygen content- dark red
• The blood volume in male is 5-6 litre
• The blood volume in female is 4-5 litre
Jegan

8. COMPONENTS OF BLOOD
Blood has 2 important components
1. Blood Plasma (55%)
2. Formed elements (45%)
Jegan

9. Jegan

10. Jegan

11. BLOOD PLASMA
• When formed elements are removed straw colored liquid called
blood plasma is left
• Blood plasma is about 91.5% water and 8.5% solutes
• Proteins found in blood is known as plasma proteins
• Hepatocytes synthesize most of the plasma proteins
 Albumins (54%)
 Globulins (38%)
 Fibrinogen (7%)
Jegan

12. • Certain blood cells develop into cells that produce gamma globulins
called antibodies or immunoglobulins
• Other solutes include electrolytes, nutrients, enzymes, hormones,
gases and waste products such as urea, uric acid, creatnine,
ammonia and bilirubin
Jegan

13. FORMED ELEMENTS
• The formed elements of the blood include 3 principle components
 RBC
 WBC
 Platelets
• RBC’s and WBC’s are whole blood cells
• Platelets are cell fragments
• RBC and platelets have few roles whereas WBC have several
function
Jegan

14. Different types of WBC are
Two types of WBC
A. Granulocytes
• Neutrophils
• Eosinophils
• Basophils
B. Agranulocytes
• Lymphocytes
• Monocytes
Jegan

15. HEMATOCRIT
• The % of total blood volume occupied by RBC is called hematocrit
• The normal range of hematocrit for
 Adult female is 38-46%
 Adult males it is 40-54%
• The hormone testosterone stimulates synthesis of erythropoietin,
which inturn stimulates production of RBC
• Level of testosterone is higher in males therefore hematocrit is
higher in males
Jegan

16. Jegan

17. • The process by which the formed elements of blood develop is
called hemopoiesis/ hematopoiesis
• Red bone marrow is the primary site for hematopoiesis
• Red bone marrow is highly vascularised
• It is present in axial skeleton, pectoral and pelvic girdles
• About 0.05-0.1% of red bone marrow cells are derived from
mesenchyme and are called pluripotent stem cells/
hemocytoblast.
• Pluripotent stem cells have capacity to develop into many different
types of cells.
Jegan

18. Jegan

19. • Stem cells in red bone marrow reproduce, proliferate and
differentiate into cells that give rise to blood cells
• Once blood cells are produced in red bone marrow, they enter
blood circulation
• Pluripotent stem cells develop into further 2 types of stem cells
called myeloid stem cell and lymphoid stem cell
• Some Myeloid stem cells differentiate into progenitor cells and
remaining myeloid cells and lymphoid cells develop into precursor
cells.
• Progenitor cells are also known as colony forming unit (CFU)
Jegan

20. Jegan

21.  CFU-E produces erythrocytes
 CFU-Meg produces platelets
 CFU-GM produces granulocytes and monocytes
• In next generation, the cells are called precursor cells also known as
blast. For eg;
 Monoblast develop into monocytes
 Eosinophilic myeloblast develop into eosinophil
 Basophilic myeloblast develop into basophil
 Neutrophilic myeloblast develop into neutrophil
Jegan

22. Jegan

23. • Lymphoid stem cells differentiate into precursor cells like
 T-lymphoblast develop into T-lymphocyte
 B-lymphoblast develop into B-lymphocyte
 NK-lymphoblast develop into Natural killer (NK) cell
• Several hormones called Hemopoietic growth factors regulate
differentiation and proliferation of particular progenitor cells
– Erythropoietin – RBCs
– Thrombopoietin – platelets
– Colony-stimulating factors (CSFs) and interleukins – WBCs
Jegan

24. FACT
Jegan

25. FACT
Jegan

26. Jegan

27. RBC
• Red blood cells (RBCs) or erythrocytes contain the oxygen-carrying
protein hemoglobin.
• Hemoglobin is a pigment that gives whole blood its red color.
• A healthy adult male:- 5.4 million RBC/ µL of blood
• A healthy adult female:- 4.8 million RBC/ µL of blood
• To maintain normal numbers of RBCs, Production = destruction
• At least 2 million new RBCs enter blood circulation per second
Jegan

28. RBC ANATOMY
• RBCs are biconcave discs
• Diameter of 7–8 µm
• Their plasma membrane is both strong and flexible.
• There are many antigens in the plasma membrane of RBCs that
account for the various blood groups such as the ABO and Rh
groups.
• RBCs lack a nucleus and other organelles.
• They neither reproduce nor carry on extensive metabolic activities.
• The cytosol of RBCs contains hemoglobin molecules;
Jegan

29. RBC Physiology
• Red blood cells are highly specialized for their oxygen transport
function.
• Mature RBCs have no nucleus.
• RBCs lack mitochondria and generate ATP anaerobically (without
oxygen).
• A biconcave disc has a much greater surface area for the diffusion
of gas molecules into and out
• Each RBC contains about 280 million hemoglobin molecules
Jegan

30. HEMOGLOBIN
• A hemoglobin molecule consists of a protein called globin
• Globin – 4 polypeptide chains (2α, 2β)
• Heme is a pigment present in each of 4 chains
• Center of each heme contains iron ion (Fe2+)
• Iron ion can combine reversibly with one oxygen molecule
• Also transports 23% of total carbon dioxide
-Combines with amino acids of globin
• Nitric oxide (NO) binds to hemoglobin
-Releases NO causing vasodilation to improve blood flow and oxygen delivery
Jegan

31. Jegan

32. Jegan

33. RBC life cycle
• Live only about 120 days
• Cannot synthesize new components – no nucleus
• Ruptured red blood cells removed from circulation and destroyed
by fixed phagocytic macrophages in spleen and liver
• Breakdown products recycled
Globin’s amino acids reused
Iron reused
Non-iron heme ends as yellow pigment bilirubin
Jegan

34. Jegan

35. ERYTHROPOIESIS
• The process of production
of RBC is known as erythropoiesis
Reticulocyte leave red bone
marrow and enter blood
circulation
Reticulocyte develop into
mature RBC within 1-2 days
Jegan

36. Less amount of RBC in blood
Low level of oxygen in blood
Cellular hypoxia
Kidney cell sense low level of oxygen
Kidney secretes erythropoietin
Erythropoietin speeds up conversion of Proerythroblast into reticulocyte
Large amount of reticulocyte enter circulation
Increased RBC’s in circulationJegan

37. FACT
Jegan

38. SYNTHESIS OF HEMOGLOBIN
• Hemoglobin synthesis requires the coordinated production of heme
and globin
• Synthesis of Hb begins in proerythroblast and continues into the
reticulocyte stage of RBC
• The process of Hb synthesis begins in mitochondria
Jegan

39. Jegan

40. • 2 Succinyl CoA+ 2 Glycine Protoporphyrin IX
• Protoporphyrin IX + Fe2+ Heme
• Heme
+ α- Globin Chain β-Globin Chain
Polypeptide chain
• 2α-Chain + 2β-Chain Hemoglobin A
Jegan

42. WBC
• Have nuclei
• Do not contain hemoglobin
• Granular or agranular depending on presence of large
conspicuous granules
• Granular leukocytes
Neutrophils, eosinophils, basophils
• Agranular leukocytes
Lymphocytes and monocytes
Jegan

43. Jegan

44. GRANULAR LEUKOCYTES
• After staining, each granular leukocytes displays conspicuous
granules with distinctive coloration
• The granules of a neutrophil are smaller than those of other
granular leukocytes.
• They do not strongly attract either the acidic (red) or basic (blue)
stain, therefore WBCs are neutrophilic ( neutral loving).
• The nucleus has two to five lobes, connected by very thin strands of
nuclear material
Jegan

45. Jegan

46. • They are large
• The uniform-sized granules within an eosinophil are
eosinophilic ( eosin-loving)
• They stain red-orange with acidic dyes
• The nucleus has two lobes connected by either a thin strand
or a thick strand of nuclear material.
Jegan

47. Jegan

48. • They are round and have variable-sized granules
• The granules of Basophil are basophilic (basic loving)
• They stain blue-purple with basic dyes
• The granules commonly obscure the nucleus, which has two
lobes.
Jegan

49. Jegan

50. AGRANULOCYTES
• Agranular leukocytes possess cytoplasmic granules, that are
not visible under a light microscope because of their small size
and poor staining qualities.
Jegan

51. • The nucleus of a lymphocyte stains dark and is round
• The cytoplasm stains sky blue
• The larger the cell, the more cytoplasm is visible
• Lymphocytes are classified by cell diameter as large lymphocytes
(10–14 µm) or small lymphocytes (6–9 µm).
• There are 3 different types of lymphocytes
 T-lymphocytes
 B-lymphocytes
 Natural Killer cells(NK cells)
Jegan

52. Jegan

53. • The nucleus of a monocyte is kidney-shaped or horseshoe-shaped
• Cytoplasm is blue-gray and has a foamy appearance
• The cytoplasm’s color and appearance are due to very fine azurophilic
granules which are lysosome.
• Monocytes migrate from the blood into the tissues, where they enlarge
and differentiate into macrophages
• Some become fixed (tissue) macrophages ; examples are alveolar
macrophages in the lungs or macrophages in the spleen.
• Other become wandering macrophages, which roam the tissues and
gather at sites of infection or inflammation.
Jegan

54. Jegan

55. • Usually live a few days
• Except for lymphocytes – live for months or years
• Far less numerous than RBCs
• Leukocytosis is a normal protective response to
invaders, strenuous exercise, anesthesia and
surgery
• Abnormal low level of WBC is termed Leukopenia
Functions of WBCs
Jegan

56. • The skin and mucous membrane are continuously exposed to
microbes and toxins
• These microbes invade deeper to cause disease
• Once pathogens enter the body, functions of WBC starts
• Many WBC will leave blood circulation and collect at site of
pathogen invasion or inflammation
• Once granular leukocytes and monocytes leave blood circulations
they will never come back
• Whereas lymphocyte continuously
recirculate
Jegan

57. • Many WBCs leave the bloodstream
• Emigration (formerly diapedesis)
• Roll along endothelium
• Stick to and then squeeze between endothelial
cells
• Endothelial cell express adhesion molecule eg.
Selectins
• Selectins stick to neutrophil and roll along
endothelial layer
• On surface of neutrophil is adhesion molecule
called integrins
EMIGRATION OF WBC
Jegan

58. Jegan

59. • Among WBC, neutrophils responds quickly to bacteria
• Neutrophil cause phagocytosis
• Neutrophil releases several chemicals to destroy bacteria
• These chemicals are
Enzyme- Lysozyme
Strong oxidants like
• Superoxide anion
• Hydrogen peroxide
• Hypochlorite anion
FUNCTIONS OF NEUTROPHILS
Jegan

60. • Neutrophil also remove waste material eg: cell debris by
phagocytosis
• Defensin- a protein that exhibit a broad range of antibiotic activity
against bacteria
• Within neutrophil, defensin
merges with Phagosome
containing microbes
• This defensin poke holes in
microbe membrane, resulting
in loss of cellular contents
Jegan

61. • Found at sites of allergic inflammation
• Eosinophil release enzyme such as histaminase that combat the
effects of histamine involved in inflammatory process during allergic
reaction
• Eosinophil also phagocytize antigen-antibody complexes
• A high eosinophil count often indicates an allergic condition or a
parasitic infection
FUNTION OF EOSINOPHIL
Jegan

62. • They are associated with hypersensitivity reaction
• At sites of inflammation, basophils leave capillaries, enter tissues,
and release granules that contain heparin, histamine, and
serotonin.
• These substances intensify
the inflammatory reaction
FUNTION OF BASOPHIL
Jegan

63. • Monocytes take longer time to reach a site of infection than
neutrophils, but they arrive in larger numbers and destroy more
microbes.
• There are 2 types of macrophages- Fixed and wandering
• These macrophages produce interleukin-1 which mediate
following action
 Acts on hypothalamus, causing rise in temperature
 Stimulates production of some globulins by liver
 Enhances production of activated T-lymphocytes
FUNTION OF MONOCYTES
Jegan

64. • The Monocyte-Macrophage system is also called
RETICULOENDOTHELIAL SYSTEM
 Histocytes in connective tissue
 Microglia in the brain
 Kuffer cell in liver
 Alveolar macrophage in lungs
 Reticular cells in spleen, lymph node and thymus gland
 Mesangial cells in glomerulus of nephron
 Osteoclast in bone
Jegan

65. • Lymphocytes are the major soldiers in immune system battles
• Three main types of lymphocytes are B cells, T cells, and natural
killer (NK) cells.
FUNTION OF LYMPHOCYTES
Jegan

66. • B cells are particularly effective in destroying bacteria and inactivating
their toxins.
• T cells attack viruses, fungi, transplanted cells, cancer cells, and some
bacteria, and are responsible for transfusion reactions, allergies, and the
rejection of transplanted organs.
• Natural killer cells attack a wide variety of infectious microbes and
certain spontaneously arising tumor cells.
Jegan

67. PLATELETS
• Disc shaped
• 2-4µm in diameter
• It has many vesicles but no nucleus
• Short life span usually 5-8 days
• 150000-400000 platelets /µL
Jegan

68. • Platelets help to stop blood loss from damaged blood vessel by
forming platelet plug
• Their granules contain chemicals, which on release promote blood
clotting
 ADP
 ATP
 CALCIUM
 THROMBOXANE
 SEROTONIN
• Low level of platelets- Thrombocytopenia
• High level of platelets- Thrombocytosis
Jegan

69. Platelets break off from megakaryocytes in red bone marrow and enter circulation
Each fragment develop into Platelets which has plasma membrane
Megakaryocytes splits into 2000 to 3000 fragments
Megakaryoblast tranform into huge cells called Megakaryocytes
Myeloid stem cells develop into Megakaryoblast
Jegan