The document provides an overview of blood, detailing its composition, functions, and the different types of blood cells including red blood cells (RBCs), white blood cells (WBCs), and platelets. It explains the role of blood in transportation, regulation, and protection, as well as specific details about blood cell types and their functions in immunity and clotting. It also describes the biochemical properties of blood plasma and the synthesis of various plasma proteins.

1. Blood
and
Its Components
DR AMITHA G

2. Contents:
1. Introduction
2. RBC
3. WBC
1. Granulocytes
1. Neutrophils
2. Eosinophil’s
3. Basophils
2. Agranulocytes
1. Lymphocytes
2. Monocyte
1. PLATELETS

3. Blood
 Blood is a bright red, viscous, slightly alkaline fluid that accounts for
approximately 7 % of total body weight

4. Introduction:-
• The average human has 5 litres of blood (Average Blood Volume is 4 to 6 liters).
• It is a transporting fluid.
• Red colour is due to the presence of oxyhaemoglobin.
• Ph - 7.4 slightly alkaline.
• Specific gravity - 1.060
• Viscosity is 5 times greater then the water i.e thicker than water.
• Blood is the only fluid tissue.
• Blood is a complex connective tissue in which living cells, the formed elements, are
suspended in fluid componenet called plasma.

5. Functions of Blood
• Transport of:
– Gases, nutrients, waste products
– Processed molecules
– Regulatory molecules.
• Regulation of pH and osmosis.
• Maintenance of body temperature.
• Protection against foreign substances.
• Clot formation.

6. Blood composition
55% Plasma (fluid matrix of water, salts, proteins, etc.)
45% Cellular elements:
 Red Blood Cells (RBCs) (Erythrocytes) : 5-6 million RBCs/ml of blood.
Contain hemoglobin which transport oxygen and CO2.
White Blood Cells (WBCs) (Leukocytes) : 5,000-10,000 WBCs/ml of blood.
Play an essential role in immunity and defense.
Include:
Granulocytes
• Neutrophils 40-70%
• Eosinophil's 0-1%
• Basophils 1-5%
Agranulocytes
• Lymphocytes 25-40% T cells and B cells
• Monocyte 2-8% (phagocytes)
 Platelets (Thrombocytes) : Cellular fragments, 250,000- 400,000/ml of blood.
Important in blood clotting.

8. Plasma
 Straw-colored liquid.
 Consists of h20 and dissolved solutes.
 Ions, metabolites, hormones, antibodies.
 Na+ is the major solute of the plasma.
Liquid part of blood
Plasma transports
Soluble food molecules
Waste products
Hormones
Antibodies

9. Plasma
ORIGIN OF PLASMA PROTEINS
Embryo
Mesenchyme cells
Albumin synthesized first
Adults
Reticuloendothelial cells of liver
Spleen, bone marrow, disintegrating blood cells, tissue cells
Gamma globulin synthesized from B lymphocytes

10. Plasma Proteins
 Constitute 7-9% of plasma
 Three types of plasma proteins: albumins, globulins, & fibrinogen
 Albumin accounts for 60-80, plasma protein made by the liver, Creates
colloid osmotic pressure that draws H20 from interstitial fluid into
capillaries to maintain blood volume & pressure
 Globulins carry lipids and are produced by lymphocytes.
 a globulin: Transport lipids and fat soluble vitamins.
 b globulin: Transport lipids and fat soluble vitamins.
 g globulin: Antibodies that function in immunity.

11. Gamma globulins are antibodies
 Fibrinogen Constitutes 4% of plasma proteins. Important clotting
factor. Converted into fibrin during the clotting process.
 Serum is fluid left when blood clots

12. FUNCTION:
1. Coagulation of blood
2. Defence mechanism
3. Role in Transport mechanism
4. Maintanance of osmotic pressure of blood
5. Acid base regulation
6. Viscosity of blood
7. Erythrocyte sedimentation rate

13. Erythrocytes / RBC
• 7-8 m diameter
• Biconcave disc shape
–  surface area
–  efficiency for diffusion of O2 &
CO2
• Flexible
• Elastic
• 100-120 day life span
• Originate in bone marrow
• Structure
– Plasma membrane
– Cytoplasm
• Hemoglobin
– Binds O2 & CO2
• No nucleus or organelles

14. Biconcave shape:
• Rapid diffusion
• Large surface area
• Minimal tension
• Squeeze through capillaries
Properties of RBS’s:
• Rouleaux formation
• Specific gravity : 1.092 to 1.101.
• Packed cell volume
• Suspension stability

15. Life span and fate of rbc’s
• Average life span -- about 120 days.
• Spleen -- Graveyard of red blood cells.
• Daily 10% red blood cells, which are senile, get destroyed in
normal young healthy adults.

16. Leukocytes or white blood cells (wbcs)
Complete cells (nuclei, mitochondria and organelles)
Move in amoeboid fashion. Can squeeze (leave the blood vessels
through) capillary walls (diapedesis), respond to chemicals
 Almost invisible, so named after stains.
 Neutrophils are the most abundant WBC, accounts for 50 – 70% of
WBCs.

17. Involved in immune function. Crucial for defense.
Positive chemotaxis: they respond to chemical signals and move
toward damage or threats.
Body increases amount in response to infection
Leukocytosis: more than 11,000 cells/mm3 indicates infection
Leukopenia: abnormally low, usually due to corticosteroids and
chemotherapy.

18. Granulocytes
Neutrophils
 Multi-lobed nucleus with fine granules
 Act as phagocytes at active sites of infection
Eosinophils
 Large brick-red cytoplasmic granules
 Found in response to allergies and parasitic worms
Basophils
 Have histamine-containing granules
 Initiate inflammation

19. Agranulocytes
are phagocytic & produce antibodies
Include lymphocytes & monocytes
Lymphocytes
 Nucleus fills most of the cell
 Play an important role in the immune response
Increase in lymphocytes counts is seen in :
• Diptheria
• Infectious hepatitis
• Mumps
• Malnutrition
• Rickets
• Syphilis
• Tuberculosis

20. Monocytes:
Monocytes
Largest of the white blood cells
Function as macrophages
Important in fighting chronic infection
Increase in monocytes seen in
 Tuberculosis
 Syphilis
 Malaria
 Glandular fever

22. Have nucleus, mitochondria, & amoeboid ability
Can squeeze through capillary walls (diapedesis)
Granular leukocytes help detoxify foreign substances & release heparin
Include eosinophils, basophils, & neutrophils

23. Neutrophils
[Polymorphonuclear leukocytes]
 Constitute 60 – 70%
 12 – 15 µm in diameter in blood smear
 Nuclei having two to five lobes
 Cytoplasm contains abundant specific granules and azurophilic granules
 Short lived with a half life of 6 – 7hrs in blood and a life span of 1 – 4 days
in connective tissue(terminal cell)
23

24. Neutrophils
[Polymorphonuclear Leukocytes]
Specific granules:
1)Azurophilic(primary): cathepsin, elastase, aryl sulphatase, acid phosphatase
2)Specific (secondary): alkaline phosphatase, lysozyme, collagenase,
lactoferrin, NADPH oxidase
3) Tertiary : gelatinase, cethepsins, glycoprotein that are inserted into
plasmalemma
24

25. Neutrophils
[Polymorphonuclear Leukocytes]
1. Specific granules: contains varies enzymes and pharmacological agents that aid the
neutrophil in performing its antimicrobial functions. In EM granules appear oblong
2. Azurophilic granules: as already indicated, are lysosomes, containing acid hydrolysis,
myeloperoxidase, antibacterial agent lysozyme, bacterial permeability increasing protein,
cethepsin G, Elastase, Nonspecific collagenase
3. Tertiary granules: contain gelatinase and cethepsins as well as glycoprotein that are inserted
into plasmalemma
25

26. Neutrophils
[Polymorphonuclear Leukocytes]
26

27. Neutrophils
[Polymorphonuclear Leukocytes]
27

28. Neutrophils
[Polymorphonuclear Leukocytes]
 Functions :
 Considered as defence against invasion of micro organisms
 Active phagocytes of small particles and are termed microphages
28

29. Neutrophils
An increased percentage of neutrophils may be due to:
 Acute infection
 Metabolic disorders
 Injection of foreign proteins
 Acute haemmorhage
 Rheumatoid arthritis
 Rheumatic fever
 Thyroiditis
 Trauma
A decreased percentage of neutrophils may be due to:
 Aplastic anemia
 Chemotherapy
 Influenza
 Radiation therapy or exposure
 Viral infection
29

30. Eosinophils
 Constitute 2-4% of leukocytes
 Same size(12-15) as neutrophil
 Nucleus is bilobed
 Abundance of large, specific granules(abt 200 per cell)stained by eosin
 Survive for 2 to 5 days
30

31. Specific granules:
 Acid phosphatase
 Arylsulfatase
 Beta- glucoranidase
 Cathepsin
 Phospholipase
 RNAase
 Eosinophilic peroxidase
 Major basic protein

32. Eosinophils
 Eosinophils are responsible for detoxification, disintegration and removal of foreign
proteins.
 The lethal substances present in the granules of eosinophils and released at the time of
exposure to parasites or foreign proteins are:
Internum :
1. Major basic protein (MBP) [50%]:arginin,histaminase
2. Eosinophil cationic protein (ECP)
3. Eosinophil-derived neurotoxin
Externum :
Chemotactic factor receptor
32

33. Eosinophil 33

34. Eosinophil 34

35. Eosinophils
Functions:
 Involved in immediate type of hypersensitivity.
 Granules release enzymes capable of degrading chemical mediaters of inflammation.
 Produce histaminase which inactivates histamine.
 Count is increased in parasitic infection.
35

36. Eosinophils
Reduced eosinophil count is seen in
 Bacterial infection
 Cushing syndrome or use of steroids
 Burns and acute infections
36

37. Eosinophils
An increased percentage of eosinophils may be due to:
 Asthma
 Allergic condition
 Collagen vascular disease
 Scarlet fewer
 Parasitic infection
37

38. Basophils
 12 – 15 µm in diameter
 Make up 1% of blood leukocytes
 Nucleus is S shaped
 Supplement the function of mast cells
 Survive for 60 to 70 hrs
Specific granules consists of:
 Eosinophilic chemotactic factor
 Heparin
 Histamine
 Peroxidase
38

39. Basophils 39

40. Basophils 40

41. Basophils
Functions :
 Increased in allergic inflammation
 Cause release of histamine, SRS-A.
 Cell membrane bears the fc receptors that have affinity for plasma Ig E-
basophil is sensitized with Ig E
 Increased by certain harmones like cortisol
 Reduced count is seen in urticaria
41

42. Basophils
An increased percentage of basophils may be due to:
 Small pox
 Chicken pox
 Polycytemia vera
 Allergic reaction
 Collagen vascular disease
 Varicella infection
A decreased percentage of basophils may be due to:
 Acute infection
 Cancer
 Severe injury
42

43. • Function of T cells :
– secrete lymphokines
– induction of apoptosis in target cells
– create pores in target cells
• Function of B cells :
– produce plasma cells-
immmunoglobins
• Nk cells/ large granular lymphocytes
– attack cancer cells and viruses

44. Platelets
• Also called thrombocytes.
• Derived from ruptured multinucleate cells (megakaryocytes)
• Smallest of formed elements.
• Are fragments of megakaryocytes.
• Lack nuclei.
• Normal platelet count = 300,000/mm3
• Survive 5-9 days
• Have amoeboid movement.
• Important in blood clotting:
• Constitute most of the mass of the clot.
• Release serotonin to reduce blood flow to area.
• Secrete growth factors
• Maintain the integrity of blood vessel wall.

45. PROPERTIES OF PLATELETS
1. ADHESIVENESS
– collagen, thrombin, ADP, Thromboxane A2, calcium ions and
von Willebrand factor.
2. AGGREGATION (GROUPING OF PLATELETS)
– ADP and thromboxane A2.
3. AGGLUTINATION
– Platelet agglutinins.

46. Functions :-
– Blood coagulation
• Form temporary haemostatic plug
• Sealing blood vessels
– Clot retraction
– Phagocytic function
– Storage & transport of 5-HT & histamine
– Repair of blood vessel.

47. Thank you