Blood Lec

BLOOD

A speck of blood the size of this letter “o” contains 5,000,000 red cells, 300,000 platelets and 7,000 white cells. Red cells alone, if removed from a single person and laid side by side, would carpet an area of 3,500 square yards.

Composition 1. Cells – rbc, wbc, platelets 2. Fibers – fibrinogen to fibrin 3. Groung substance - plasma

Erythrocytes • • • • • • •

Anucleate , biconcave, 7.5um diameter No other organelles Most prevalent in peripheral blood 33% hemoglobin Spectrin – cytoskeleton Life span – 120 days Abnormalities

Leucocytes • Granulocytes 1. Neutrophil 2. Eosinophil 3. Basophil Granules 1. Specific 2. azurophile

• Agranulocytes 1. Lymphocytes 2. Monocytes No specific granules

Neutrophil • • • •

60-70% of wbc 12-15 um 2-5 lobes Life span 1-4 days

Granules 1. Azurophilic granules - stain with azure dye ; diagnostic - 20% of granule population - visible in lilght microscope 2. Specific granule - 80% of granule population - not visible in light microscope

Eosinophil • • • • •

2-4% of wbc Bilobed nucleus 12-15 um Large specific granules Allergic and parasitic infection

Basophil • • • • •

< 1% of wbc Irregular lobed nucleus Metachromatic specific granules Supplement to mast cells Inflammatory response

Lymphocyte • • • • • •

Most common agranulocyte Not confined to peripheral blood 5-18um diameter No specific granule Converts to plasma cell Key to immune system

Monocyte • • • •

Oval, kidney, horse-shoe shaped nucleus 12-18 um diameter No specific granules Precursor to macrophage

Platelets • • • • •

Non-nucleated disk like fragment 2-4 um Blood clotting 200,000-400,000 per microliter 10 day life span

Platelet function 1. Primary aggregation – form platelet plug 2. Secondary aggregation 3. Blood coagulation – formation of fibrin to form a blood clot 4. Clot retraction 5. Clot removal