Circulatory system Flashcards
what are the 2 names of the valves in the heart?
atrioventricular valve
= left one is mitral atrioventricular valve = 2 cusps
=right one is tricuspid atrioventricular valve = 3 cusps
semilunar valves
= aortic semilunar valve controls blood flow leaving left ventricle through aorta
=pulmonary semilunar valve controls blood flow leaving through right ventricle
what makes up the circulatory system?
cardiovascular system & lymphatic system
what is the functions of circulatory system?
- distribution of gases & other molecules for nutrition, growth & repair
- chemical signalling (hormones)
- mediate inflammation & host defence response
describe the pulmonary circulation
starting at right atrium -> right ventricle -> blood leaves through right & left pulmonary arteries to lungs (1 exception where arteries carry de-oxygenated blood) and then coming back from the lungs into left atrium through 4 pulmonary veins (1 excepetion of veins carrying oxygenated blood)
describe the systemic circulation
starting at left atrium -> left ventricle and then blood pumped out with oxygenated blood still through aorta (aorta divides to arterioles then capillaries for exchange where blood then deoxygenated then back to venules and then veins = superior & inferior vena cava that run into right atrium & back to pulmonary circulation
what is
a) systole
b) diastole
a) contraction
b) relaxation
what is orientation of heart? (describe anterior view)
mostly right ventricle stretching across front with right atrium at top and then left ventricle taking up most of left side with only a little bit of left atrium at top left
LA = posterior surface of heart
LV = mostly left border of heart & inferior surface
RA = right border
RV = most of anterior surface of heart
describe electrical conducting system of heart
- Electrical impulse starts spontaneously at sinoatrial node →Causing both atria to contract
- Travels to AV Node at atrioventricular septum
- Travels down right and left bundles in Bundles of His
- Spreads out to myocardium through conducting fibres →Causing both ventricles to contract
what does birfurcate & trifurcate mean?
when arteries split into 2 or 3 routes ( like tributaries in river)
what terms indicate that an artery will divide again?
common or trunk
what is vasodilation?
Relaxation of the smooth muscle and widening of the lumen to INCREASE blood flow to the organ/tissue supplied
what is vasoconstriction?
Contraction of smooth muscle to REDUCE blood flow to the organ/tissue supplied
what is sympathetic tone?
background or low level contraction of smooth muscle in arterioles due to tonic (continuous) conduction of action potentials to arterioles by sympathetic nerve
what is an anastamoses?
communicating connections between multiple branches of artery to provide numerous potential detours in case usual pathway obstructed (like knee flexion)
what does collateral circulation mean?
collateral circulation is when main channel occluded so smaller alternate channels can increase in size supplying blood supply to structures distal to blockage