1. Fifth lecture

2. 2-White blood cells Nucleated cells. larger than RBC’s.
Approx. 1 x 1010 per liter.
Involved in defense against pathogens.
Can move through capillary wall to act locally at site of infection.
Attracted to trauma site by chemotaxis.

3. 2-White blood cells Agranulocytes Granuloyctes Lymphocytes Monocytes
Neutrophils
Basophils
T Cells
B Cells
Eosinophils
Killer T Cells
Helper T Cells

4. 2-Leukocytes (WBCs) Part of defense system:
Protect against bacteria, viruses, parasites
Attracted to sites of infection.
Diapedesis & chemotaxis: leave capillary by squeezing between endothelial cells.
Ameboid movement:
Travel toward infection
Originate in bone marrow.
They are classified into:
A-Granulocytes
B-A granulocytes

5. Diapedesis

7. Granulocytes WBCs with granules in cytoplasm Neutrophils Eosinophils
Visible with LM
Neutrophils
Eosinophils
Basophils
Phagocytic
Larger than RBCs
Lobed nuclei

8. Formation of granulocytes
Promyelocytes
Eosinophilc myelocytes
Neutrophilic myelocytes
Basophilic myelocytes
basophils
eosinophils
neutrophils
It takes about 10 days for the mature WBC’s to from the precursor cells at which they are released into the circulation.
Colony Stimulating Factors govern the rate of WBC synthesis.

9. Neutrophils
60% of WBCs.
half-life of 6 hours so need to produce 100 billion per day for normal function!
Lobed nucleus.
Light staining granules.
Digestive enzymes.
Function
Phagocytize & destroy bacteria.
First cells to respond to infection.
Secrete antibacterial chemicals.
Phagocytize & digest bacteria.

10. Eosinophils 1-4% of WBCs. Lobed nucleus. Eosin-staining granules.
Phagocytize allergen-Ab complexes.
increased following allergic response.
Attack parasites.

11. Basophils 0.5% of WBCs. Lobed nucleus.
Large granules stained dark purple.
Release histamine and heparin.
Trigger inflammation.

12. Lymphocytes A granulocyte 20-45% of WBCs
Spherical, dark-staining nucleus
Thin rim of blue staining cytoplasm
Each lymphocyte recognizes and acts against a specific antigen

13. Lymphocytes Derived from lymphoblasts which divide a number
of times to form pro-lymphocytes.
Pro-lymphocytes mature into B or T lymphocytes
in lymphoid tissue i.e. thymus, spleen
T lymphocytes can attack foreign cells directly.
B lymphocytes transform into plasma cells and secrete antibodies.

14. Monocytes A granulocyte 4-8% of WBCs Horseshoe shaped nucleus.
originate from monoblasts.
Life span 72 hours, after which they migrate to connective tissue where they remain for up to 3 months.
Migrate to spleen, liver, lungs and lymph nodes where they phagocytose invading pathogens and are termed macrophages.

15. 3-Platelets (thrombocytes)
Not strictly speaking cells.
Really membrane bound cell fragments budded off of bone marrow cells and released in to circulation.
Rarely nucleated and only 2-4m in diameter.
Life span 10 days.

16. 3-Platelets (thrombocytes)
Adhere to damaged vessel walls
and exposed connective tissue to
mediate blood clotting.
DO NOT adhere to healthy intact
endothelium.
Fragments of megakaryocytes in
bone marrow.
Attracted to damaged places.