Transcript BLOOD
BLOOD Components of Blood Red blood cells = erythrocytes White blood cells = leukocytes Cell fragments = platelets Liquid = plasma In your 5 liters of blood… There are: • 45% cells • 55% plasma • Mostly erythrocytes • Fewer leukocytes and platelets • Dissolved substances 4-6 million erythrocytes per cubic mm • 5-10,000 leukocytes per cubic mm • 130,000 – 360,000 platelets per cubic mm Erythrocytes • Biconcave discs • Carry oxygen in hemoglobin • Lack nuclei • Cannot reproduce • Live about 4 months • Cell count used in disease diagnosis Production and Destruction • Nutrients necessary include vitamin B12, folic acid, iron • Cell count is kept at constant level • Production controlled by the hormone erythropoietin •After 4 months, destroyed in liver and spleen •Byproduct is bilirubin •Too much bilirubin leads to jaundice Leukocytes • Protect against infection and disease • Can leave the bloodstream to fight infection • Have a nucleus • Cell count used to diagnose disease Relative numbers of Leukocytes neutrophils eosinophils basophils monocytes lymphocytes Platelets • • • • • Cell fragments Also called thrombocytes Essential for blood clotting Lack nuclei Live about 10 days • 92% water • Contains dissolved substances: • Plasma proteins including albumins, globulins, and fibrinogen • Blood gases (O2, CO2) • Plasma nutrients: amino acids, simple sugars, lipids from digestive tract Plasma Plasma • Nitrogenous substances such as urea, uric acid. These are toxic wastes that must be excreted in urine • Electrolytes: sodium, calcium, phosphate, etc. Cholesterol: good or bad? • It’s normal to have some • It is needed to form cell membranes, hormones, and some other tissues • But a high level is a risk for heart disease Cholesterol: good or bad? • Lipoproteins carry cholesterol in the blood plasma • LDL is “BAD” (Low density) • HDL is “Good” (high density) Neutrophil Eosinophil Basophil Monocyte Lymphocyte Which type of leukocyte is it? Which type of leukocyte is it? Which type of leukocyte is it? Which type of leukocyte is it? Which type of leukocyte is it? Which type of leukocyte is it? Which type of leukocyte is it? Which type of leukocyte is it? Which type of leukocyte is it?