cardiovascular - lecture 4 Flashcards
what do right and left pulmonary arteries do
blood from right side of heart goes to right lung
what do right and left pulmonary veins do
blood from lungs which is now oxygenated returns to heart - left side
describe arteries and veins
arteries = move blood from heart, carry oxygenated blood (mostly)
veins = bring blood back to heart, carry deoxygenated blood (mostly)
describe walls/septums
inter atrial septum
inter ventricular septum = boundary between right and left halves
right ventricular free wall = 1/10th, low pressure system
left ventricular free wall = v thick, lots of power, high pressure system
describe coronary circulation - gen
heart has own circulation
coronary arteries = branch off above valve that feeds aorta
blood returns through veins and goes back to right atrium
describe coronary arteries
branch off just above aortic valve
supply the heart muscle with oxygenated blood
describe coronary veins
coronary veins and coronary sinus empty deoxy blood into right atrium
what happens when blockage of coronary arteries
myocardial infarction = heart attack
plaque if lodged = turbulent flow
intervention needed
name cardiac valves
tricuspid - right heart
pulmonary valve (pulmonic)
mitral valve (bicuspid) - left heart
aortic valve
make sure blood is not back flowing
describe cardiac valves
left av = bicuspid = 2 leaflets
right av = tricuspid = 3 leaflets
left aortic semi lunar valve
right pulmonary semi lunar valve
semilunar = looks like half moon
describe chordae tendinae and papillary muscles
chordae = connect to muscle and holds on
prevents prolapse from massive amounts of pressure
papillary muscle = contracts when ventricle contracts
both make structure strong
what is pericardium
bag that surrounds heart
pericardial sac
does not expand, but v flexible, prevents overfilling
protects heart physically from damage and rest of body
provides pericardial fluid (~70ml)= lubricant to allow heart to freely contract with no friction, generated from serous membranes
what is epicardium
outer layer of heart tissue
epithelial cells
what is myocardium
muscle
specialized cells
what is endocardium
inner layer of heart tissue
endothelial cells
what is fibrous ring
between atria and ventricles = thick part
electrically isolates it
except av small node
sinus node aka
sinoatrial node
sa node
av node aka
atrioventricular
bundle of his aka
his bundle
av bundle
atrioventricular bundle
purkyne fibers aka
purkinje fibers
his purknje system aka
bundle of his + left and right bundle branches + purkinje fibers
what is pace making activity
sa node = main pacemaker
av node and cells of his purkinje system can beat spontaneously if sa node fails to fire
his purkinje system = 1/700ms
purkinje alone = 1/2secs or so
describe activation sequence - 1
sinus node
small cluster cells specialized = electrical properties allow them to beat on their own, even if take heart out of body
beat 1/sec
electrical cascade = end up with wave of propagation and propagates through atria
describe activation sequence - 2
wave from sa node now propagates through atria