how is blood supplied to the heart, what is myocardial infaraction
cornary arteries and veins, when blood to heart is stopped/blocked (heart attack)
1 of 29
describe the coverings of the heart and its role
pericardium- made up of parietal and viseral layer with fluid between. protects and anchors heart
2 of 29
difference between artery and vein structure, why?
atery has thicker walls as blood under higher pressure
3 of 29
what is heart contraction and relaxation called
diastole is relaxation, systole is contraction
4 of 29
explain first step of cardiac cycle
artial diastole, then artial systole.- blood flows first passively into ventrile and AV valves open, systole means last bit of blood squeezed into ventricle
5 of 29
what is seond step of cardiac cyle
ventricle filling
6 of 29
explain 3rd step in cardiac cycle
ventricular systole- atria diastole, incerased ventricular pressure means AV valve closes, isovolumetric phase as ventricular pressure is insuffient to open semilunar valve. pressure high enough and semilunar valve opens
7 of 29
explain stage 4 in cardiac cycle
ventricular diastole- ventricle relaxses, back flow means semilunar valve closes. blood flows into relaxed atria
receptors stimulated, activates parasympathetic ns, sa node inhbited to hr drops and bp drops
19 of 29
what is preload.
tension applied to muscle before it preforms, meaure of ventriclar stretch. higher filling pressurre= higher preload
20 of 29
what is afterload
load that reloaded muscle haas to work against. pressure required by ventricle to force out blood during systole
21 of 29
affect of incerased preload and after load on co
increased preload= increased co increased afterload= decreased co
22 of 29
what frank starling mechanism
preload increased when venous return higher as it causes increased ventricular filling. happnens during exersise
23 of 29
describe retin-angiotensin-aldosteron system
retin-secrted by kideny in repsonse to low bp/ blood volume. retin converts angiotensin-angiotenisn 1. angiotensin coverting enzyme (ACE) coverts angiotensin 1 - angiotensin2
24 of 29
actions of angiotensin 2 (4)
1. vasoconstricton to increase periphal resistance 2. stims alddersterone to be released from adrenal gland (na+ and h20 reabsorbtion in kideny so blood volume increases) 3. stims negitive feebcak of retin 4. stims hypothalmus thirst- sympathetic activity
25 of 29
ACE inhbiters mechanims
inhbits angiotensin formation, less aldersterone released, less na+ and h2o reabsorbtion
26 of 29
mechanim of a ace recetpor blocker
blocks angiotensin receptors adrenal gland so less aldresterone activity
27 of 29
what is systolic heart failure
weakened heart muscle so cant squeeze
28 of 29
what is diastolic heart failure
stiff muscle so cant relax properly
29 of 29
Other cards in this set
Card 2
Front
describe the coverings of the heart and its role
Back
pericardium- made up of parietal and viseral layer with fluid between. protects and anchors heart
Card 3
Front
difference between artery and vein structure, why?
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