Circulation has two systems: pulmonary circulation, from heart to lungs and back, and systemic circulation, from heart to body tissues and back.
Arteries carry blood away from heart.
Veins carry blood back to heart.
Arteries become arterioles which become capillaries.
Capillaries is where exchange of nurtients, gases, and waste occurs.
Capillaries drop off carbon dioxide to be exhaled and leave with oxygenated blood.
Veins have thinner walls than arteries, have valves, are more numerous, hold more blood than arteries. .
Blood in veins is deoxygenated and has higher levels of CO2 .
Veins carry DeO2 blood because they are dropping off O2 to tissues then go back to heart/lungs where we exhale CO2.
Base of heart proximal to head.
Apex of heart is distal.
Right side of heart collecting blood from body and sending it to lungs to pick up O2 and get rid of CO2.
Left side of heart collect blood from lungs and pumps it through body.
Heart has four chambers.
Two small upper chambers called atria.
Two larger lower chambers called ventricles.
Interatrial septum is wall that separates two atria.
Interventricular septum is the wall between the two ventricles.
Right atrium is collecting chamber when blood is returned to heart by vena cava after its trip through body.
Once blood collected it drains to right ventricle. .
Blood returning from lungs flows into left atrium then into left ventricle.
Large veins bring blood to atria call superior or inferior vena cava.
Large veins bring blood back to left atrium are pulmonary veins.
Large arteries carry blood away from ventricles.
Pulmonary trunk (pulmonary arteries) carry blood from right ventricle to lungs.
Aorta carries blood from left ventricle to body.
Valves between each atrium and the ventricle on same side called atrioventricular (AV) valves.
On right side is tricuspid valve.
On left side is bicuspid, or mitral, valve.
Between ventricles and large arteries that carry blood away from heart are semilunar valves.