THE CIRCULATORY (CARDIOVASCULAR) SYSTEM

THE SIX JOBS OF THE CIRCULATORY SYSTEM...

Deliver oxygen to all cells Remove carbon dioxide from all cells Transport food to all body cells Carries wastes away Supplies the body with defenses against invaders Carries chemical messengers

THE FOUR CHAMBERS OF THE HUMAN HEART... Left atrium Left ventricle Right atrium Right ventricle

VALVES Prevent blood from backing up into the upper chambers of the heart “One-Way Doors”

RIGHT VENTRICLE pumps blood only a short distance to the lungs LEFT VENTRICLE pumps blood to every part of your body

ARTERIES... Carries blood AWAY from the heart Thick, muscular walls Pulse

CAPILLARIES... Connect arteries to veins Thin walls Allow oxygen and carbon dioxide to diffuse (move) through All body cells are near a capillary

VEINS... Carry blood BACK to the heart Thinner walls than arteries VALVES--keep the blood from moving backwards

PLASMA... Liquid portion of blood 90% water Carries nutrients

RED BLOOD CELLS Round, doughnut shaped cells with flat centers Thin and numerous 120 day life span Have HEMOGLOBIN, which transports oxygen and carbon dioxide

WHITE BLOOD CELLS... Larger and less numerous than RBC Protects the body against invaders

PLATELETS... Fragments of cells Have no color More numerous than WBC, less numerous than RBC Help in blood clotting

Hemoglobin By the 1860’s physiologists discovered that the red blood cells are packed with a protein called hemoglobin.

HEMOGLOBIN... An iron-containing protein that transports oxygen to the body and carbon dioxide to the lungs Found in Red Blood Cells

ATHEROSCLEROSIS Thickening and hardening of the arteries Cholesterol collects on artery walls, narrowing the artery and reducing the normal movement of blood

HYPERTENSION Blood pressure goes up and remains above normal Makes the heart work harder (leaks may develop in blood vessels) “Silent Killer”--no obvious symptoms

TO DECREASE THE RISK OF CARDIOVASCULAR DISEASES... Watch your weight Decrease salt in your diet Eat healthy ; exercise Avoid stress Stop smoking and alcohol consumption