fifth lecture. 2-white blood cells nucleated cells. larger than rbc ’ s. approx. 1 x 10 10...
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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.
Neutrophils
2-White blood cells
Granuloyctes Agranulocytes
Basophils
Eosinophils
Monocytes Lymphocytes
B Cells T Cells
-
Helper T Cells
Killer T Cells
22--Leukocytes (WBCs)Leukocytes (WBCs)
Part of defense system:Part of defense system: Protect against bacteria, viruses, parasitesProtect against bacteria, viruses, parasites
Attracted to sites of infection.Attracted to sites of infection. Diapedesis & chemotaxis: leave capillary Diapedesis & chemotaxis: leave capillary
by squeezing between endothelial cells.by squeezing between endothelial cells. Ameboid movement:Ameboid movement:
Travel toward infectionTravel toward infection Originate in bone marrow.Originate in bone marrow. They are classified into:They are classified into:
A-Granulocytes A-Granulocytes B-A granulocytesB-A granulocytes
GranulocytesGranulocytes
WBCs with granules in cytoplasmWBCs with granules in cytoplasm– Visible with LMVisible with LM
NeutrophilsNeutrophils EosinophilsEosinophils BasophilsBasophils PhagocyticPhagocytic Larger than RBCsLarger than RBCs Lobed nucleiLobed nuclei
Promyelocytes
Basophilic myelocytes
Eosinophilc myelocytes
Neutrophilic 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.
Formation of granulocytes
NeutrophilsNeutrophils
60% of WBCs.60% of WBCs. half-life of 6 hours so need to half-life of 6 hours so need to
produce 100 billion per day for produce 100 billion per day for normal functionnormal function!
Lobed nucleus.Lobed nucleus. Light staining granules.Light staining granules.
– Digestive enzymes.Digestive enzymes. Function Function
– Phagocytize & destroy bacteria.Phagocytize & destroy bacteria. First cells to respond to First cells to respond to
infection.infection. Secrete antibacterial chemicals.Secrete antibacterial chemicals. Phagocytize & digest bacteriaPhagocytize & digest bacteria..
EosinophilsEosinophils
1-4% of WBCs.1-4% of WBCs. Lobed nucleus.Lobed nucleus. Eosin-staining granules.Eosin-staining granules. Phagocytize allergen-Ab complexes.Phagocytize allergen-Ab complexes. increased following allergic response.increased following allergic response. Attack parasites.Attack parasites.
BasophilsBasophils
0.5% of WBCs.0.5% of WBCs. Lobed nucleus.Lobed nucleus. Large granules stained dark Large granules stained dark
purple.purple. Release histamine and Release histamine and
heparin.heparin. Trigger inflammation.Trigger inflammation.
LymphocytesLymphocytes
A granulocyte A granulocyte 20-45% of WBCs20-45% of WBCs Spherical, dark-Spherical, dark-
staining nucleusstaining nucleus Thin rim of blue Thin rim of blue
staining cytoplasmstaining cytoplasm Each lymphocyte Each lymphocyte
recognizes and acts recognizes and acts against a specific against a specific antigenantigen
LymphocytesLymphocytes
T lymphocytes can attack foreign cells directly.T lymphocytes can attack foreign cells directly.
B lymphocytes transform into plasma cells and secrete B lymphocytes transform into plasma cells and secrete antibodies.antibodies.
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
MonocytesMonocytes
A granulocyteA granulocyte 4-8% of WBCs4-8% of WBCs Horseshoe shaped nucleus.Horseshoe shaped nucleus. originate from monoblasts. Life span 72 hours, 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 Migrate to spleen, liver, lungs and lymph nodes where they phagocytose invading nodes where they phagocytose invading pathogens and are termed macrophages.pathogens and are termed macrophages.
33--Platelets Platelets (thrombocytes)(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 2-4m in diameter.
Life span 10 days.
DO NOT adhere to healthy
intact
endothelium.
Fragments of Fragments of
megakaryocytes in megakaryocytes in
bone marrow.bone marrow.
Attracted to damaged places.Attracted to damaged places.
Adhere to damaged vessel walls
and exposed connective tissue to
mediate blood clotting.
33--Platelets Platelets (thrombocytes)(thrombocytes)