Circulation Read Chapter 31

1. BloodBlood carries to the cells

Oxygen produced by R______________Nutrients processed by D_____________

Blood carries away waste materials from the cellsCarbon dioxide taken to the L_______Urea, taken to the K_________

Blood also transportsHormones (molecules that regulate the function of tissue or organs)Enzymes (molecules that catalysis reactions)Antibodies (protein that are on B-cells and attach to & kill foreign bodies)

What is blood made up of?

Plasma, mostly water. carries dissolved molecules & plasma proteins for clotting

Red blood cells transport O2 in hemoglobin, no nucleus, can’t repair them selves. Have a 120 day life-span

•White blood cells, defend body against invaders

The shape of blood cells

Blood clottingWhen plasma comes into contact with tissue it reacts to produce a protein (fibrin) which clump together to form a mesh which traps red blood cells & platelets to form a clot.

The Cardiovascular SystemThis is the Heart & blood vessels

The Blood vessels:Arteries Carries blood away from heart to the body. Thick , tough elastic walls to withstand high pressureVeins Carries blood to the heart from the body. Have larger passageways.Capillaries Very fine blood vessels where exchange of substances between the blood & cells occurs. Most molecules leave capillaries by diffusion or bulk flow. Fluids renter the capillaries by osmosis

Pulmonary veinBlood moves from _________ To _______________

Pulmonary arteryBlood moves from _________ To _______________

AortaBlood moves from _________ To _______________

Superior vena cavaBlood moves from _________ To _______________

Inferior vena cavaBlood moves from _________ To _______________

The HeartThe heart has evolved from the simple two chambered heart in fish to the three chambered heart in amphibians to our four chambered heart.Disadvantages of the fish heart

Not enough power to make blood flow fast after the gillsAdvantages of our heart

More efficientHigher pressureHigher metabolic rate & so higher levels of activity

Relatively constant body temperature

Structure of the HeartThe interior of the Heart is divided into 4 chambersRight atrium Deoxygenated blood from the body enters here via the superior & inferior veins.

Left atrium Oxygenated blood returning from the lungs enters here via the pulmonary vein.

Right ventriclePropels deoxygenated blood through the pulmonary arteries to the capillaries of the lungs

Left ventricle Propels oxygenated blood through the aorta to the capillaries in body tissue

Valves Stop back flow of blood between the chambers & also back into the blood vessels during contraction

The atria are thin walled so they can expand to take in blood & both contract at the same time to push blood through the valves into the ventricles.

The ventricles contract simultaneously, this closes the valves preventing back flow

The healthy heart of an adult beats 70 times a minute at rest