Cardiovascular System Flashcards
(102 cards)
what is the heart
a muscular organ whose primary function is to collect and pump blood around the body
approximately how many heart beats a day
100,000 equivalent to approx 7000L/day
anatomical location of heart: region
mediastinum - the central compartment of the thoracic cavity, between the lungs
anatomical location of heart: position relative to rest of body
- posterior to sternum (breastbone)
- medial to lungs
- anterior to vertebral column
- superior to diaphragm
- within thoracic cage
- base parallel to 2nd rib
- apex (pointy bottom) on diaphragm
what are the four chambers of the heart
right atrium, right ventricle, left atrium, left ventricle
which chamber pumps blood to the body
left ventricle
which chamber pumps blood to the lungs
right ventricle
which chamber receives blood
atria (ra: the body, la: the lungs)
what are the three layers of the heart wall
endocardium (inner), myocardium (middle), epicardium (outer)
what is the pericardium
a double-layered sac that encloses the heart (fibrous & serous)
what is the function of pericardial fluid
reduces friction during heartbeats
what are the four valves of the heart
tricuspid, pulmonary semilunar, mitral (bicuspid), aortic semilunar
what do the AV valves do
prevent back flow from ventricles to atria
what do semilunar valves do
prevent backflow from arteries into ventricles
what do semilunar valves do
prevent back flow from arteries into ventricles
what re the great vessels of the heart
aorta, pulmonary trunk, pulmonary veins, superior & inferior vena cava
what are coronary (cardiac) vessels
arteries and veins that supply blood to the heart muscle itself
structure of arteries vs veins
arteries have thicker walls (more smooth muscle), veins have valves and larger lumens
what are capillaries
thin walled vessels where exchange of gases, nutrients, and waste occurs
what initiates the heartbeat
sinoatrial (SA) node - the pacemaker of the heart
order of conduction
SA node -> AV node -> bundle of his -> bundle branches -> purkinje fibres
function of AV node
slows signal before it reaches venrtricles
what is diastole
relaxation phase - ventricles fill with blood
what is systole
contraction phase - ventricles eject blood