blood components of blood red blood cells = erythrocytes white blood cells = leukocytes cell...
Post on 31-Dec-2015
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Components of Blood
Red blood cells = erythrocytes
White blood cells = leukocytes
Cell fragments = platelets
Liquid = plasma
In your 5 liters of blood…
4-6 million erythrocytes per cubic mm
• 5-10,000 leukocytes per cubic mm
• 130,000 – 360,000 platelets per cubic mm
There are:• 45% cells• 55% plasma• Mostly erythrocytes• Fewer leukocytes and
platelets• Dissolved substances
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
Platelets
• Cell fragments
• Also called thrombocytes
• Essential for blood clotting
• Lack nuclei
• Live about 10 days
Plasma• 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
• 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)
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