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.