A&P for Cardiac

Question 1

describe the pericardium

Answer 1

fibrous outer sac, serous parietal layer that minimizes friction during contraction, and visceral layer aka epicardium

Question 2

what are the three layers of the heart

Answer 2

epi, myo, and endocardium

Question 3

where is the tricuspid valve

Answer 3

between RA and RV

Question 4

where is the pulmonary valve

Answer 4

between RV and Pulm Artery

Question 5

where is the mitral valve

Answer 5

between the LA and LV

Question 6

Without neural influence, the impulse from the SA node beats at _______ bpm (inherent rhythmicity)

Answer 6

100

Question 7

what is the purpose of the AV node

Answer 7

delay A-V impulse until atria have had time to eject their contents into the ventricles

Question 8

what is the inherent rhythmicity of the AVN

Answer 8

40-60 bpm

Question 9

what is the p wave

Answer 9

atrial contraction

Question 10

what is the QRS wave

Answer 10

ventricular contraction

Question 11

what is the T wave

Answer 11

ventricular relaxation

Question 12

how does the vagus nerve exert its influence over the heart?

Answer 12

parasympathetically - decreases HR

Question 13

how do the upper thoracic nerves and rami of the sympathetic trunk exert their influence over the heart?

Answer 13

sympathetically - inc HR

Question 14

the sympathetic receptors of the heart are primarily _________, and stimulation by ________ increases overall activity of the heart

Answer 14

beta-adrenergic; norepinephrine

Question 15

the sympathetic receptors of the peripheral vasculature are primarily __________, and when activated they can cause systemic _________

Answer 15

alpha-adrenergic; vasoconstriction

Question 16

describe the pressure-resistance relationship of the R side of the heart

Answer 16

low pressure system with little resistance from the pulm arteries

Question 17

describe the pressure-resistance relationship of the L side of the heart

Answer 17

high pressure system with high resistance from systemic circulation

Question 18

what is the primary determinant of oxygen delivery

Answer 18

cardiac output!

CO = SV x HR

Question 19

what are the three factors that influence stroke volume

Answer 19

preload (starling effect), afterload, and myocardial contractility

Question 20

how does preload influence stroke volume

Answer 20

increased preload = increased SV

Question 21

how does afterload influence stroke volume

Answer 21

increased afterload = decreased SV

Question 22

what is the frank-starling effect

Answer 22

increase in ventricular volume increases systolic force but excessive stretching in fluid overload impairs actin/myosin interaction thus impairing contractility

Question 23

blood pressure is a product of __________ and ____________

Answer 23

CO and TPR

Question 24

what is pulse pressure and what can it tell you about heart disease

Answer 24

pulse pressure is the difference between SBP and DBP and increased pulse pressure is a risk factor for heart disease

Question 25

where in the body do we regulate BP?

Answer 25

vasomotor center in the medulla which mediates sympathetic and vagal inputs

Question 26

what is the short term regulator of BP

Answer 26

arterial baroreceptors - if BP increase, CO and TPR decrease

Question 27

what is the long term regulator of BP

Answer 27

renin-angiotensin-aldosterone system - kidneys compensate for BP decrease by activating angiotensin 2 which leads to vasoconstriction

Question 28

water retention in the kidneys is another long term regulatory mechanism in response to low blood volume, but how does it work?

Answer 28

low blood volume stimulates posterior pituitary ADH which leads to vasopressin upregulation