Circulatory System
Blood
Blood• In general, the blood is a fluid tissue helping
to maintain homeostasis for all cells in the body.
• Transport of needed substances to body cells. (oxygen, amino acids, glucose, fatty acids, glycerol, salts, etc.)
• Transport of wastes from cells. (urea, water, carbon dioxide in the form of the bicarbonate ion)
• Helps to maintain a constant body temperature
• Aids the body in fighting disease
Composition of blood• Blood transports materials
through out the body inside blood vessels.
• Blood is a tissue of fluid & cells– plasma
• liquid part of blood• dissolved salts, sugars, proteins, and
more
– cells • red blood cells (RBC)
– transport O2 in hemoglobin
• white blood cells (WBC)– defense & immunity
• platelets– blood clotting
Plasma• Straw colored,
nonliving part of blood.
• 90% Water• Helps to regulate
body temperature• Contains Electrolytes• Plasma transports
blood cells, products of digestion and hormones throughout the body.
How much blood is in the human body?
• About 5 liters About 7 % of your body mass About 4.5- 5.6 Liters in an adult human
Men = 5.6 Liters Women = 4.5 Liters Pregnant woman = 5.0 Liters
The Functions of Blood
Delivers: Picks Up: - Nutrients - waste kidneys- Oxygen, Water, - carbon dioxide
lungs minerals- Hormones and enzymes - heat skin- Pollutants
Erythrocytes Red Blood cells:•Shaped like round plates indented in the center.•Have no nucleus when mature•Most numerous•Smaller than white blood cells•Produced in the red marrow of long
bones•Destroyed in the liver and spleen•Contains the iron protein compound HEMOGLOBIN whose chief function is to combine with oxygen and carry it to cells
Why is blood red?
• Blood is red because it contains hemoglobin and iron rich pigment.
What does hemoglobin do
• Hemoglobin picks up the oxygen molecules and drops off CO2
• 250,000 hemoglobins in 1 red blood cell
Carbon Monoxide
• Binds to RBC better than oxygen.
• Not good • Kills us silently• Cant smell it or taste
it.
Anemia
• Occurs when the blood does not have enough hemoglobin.
• Treated by taking in more iron
• Because iron makes up hemoglobin
Leukocytes
White blood cells•Fight infections by forming antibodies or engulfing bacteria•Large in size, several different types•Have a nucleus•Phagocyte•About 8,000 per drop of blood•Most are formed in the bone marrow
or in the lymph tissue
Phagocytes
• Engulf bacteria and viruses by phagocytosis
• Able to leave the bloodstream and move between the cells of the body
by squeezing through the
capillary walls
Lymphocytes
• Produce antibodies which clump bacterial poisons or bacteria (antigens)– Antigens: foreign substances in the body
Platelets
• Smallest part of blood• No nucleus• Live 2-4 days• Involved in clotting of
blood• Creates fibrin
– Enzyme that helps clot blood
Blood Clotting• Involves a series of
enzyme controlled reactions resulting in the formation of protein fibers that trap blood cells and form a clot
Blood Clottingchemicalemergencysignals
plateletsseal the hole protein fibers
build the clot
What’s wrong with this picture?
Sickle Cell Anemia
• Genetic disease• Red blood cells
become sickle shape• Cant carry as much
oxygen
Malaria
• Disease that attacks the RBC.
• Causes high fever• If you have sickle cell
shaped RBC can not get the disease.
Leukemia
• Form of cancer in which the bone marrow makes too many white blood cells.
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