Cardiology

Question 1

Velocity of Blood Flow=

Answer 1

Flow/Cross sectional area (V=Q/A)

Question 2

Flow=

Answer 2

pressure difference/resistance

Question 3

Flow (Q) is directly proportional to

Answer 3

pressure gradient

Question 4

Flow (Q) is inversely proportional to

Answer 4

resistance

Question 5

Total Peripheral Resistance=

Answer 5

P(arterial)-P(venous)/Q(flow)

Question 6

Dichotic notch

Answer 6

aortic or pulmonary valve closure

Question 7

systolic pressure

Answer 7

highest arterial pressure in cardiac cycle

Question 8

Diastolic pressure

Answer 8

lowest arterial pressure during cardiac cycle. occurs at end of diastole

Question 9

pulse pressure

Answer 9

systolic-diastolic pressure

Question 10

mean arterial pressure

Answer 10

diastolic pressure + 1/3 pulse pressure (estimates mean pressure)

Question 11

stroke volume, what’s normal?

Answer 11

volume of blood ejected from the one ventricle on a single cardiac cycle (heartbeat) ~70cc’s

Question 12

cardiac output

Answer 12

volume blood pumped by heart per minute. Cardiac Output=stroke volume x heart rate

Question 13

Function of the AV node

Answer 13

slows conduction of impulses allowing atrial blood to be pumped into ventricle before the electrical impulses passes to bundle of His/Purkinje system, resulting in ventricular contraction

Question 14

Function of SA node

Answer 14

acts as pacemaker of heart

Question 15

Positive Inotrope

Answer 15

increases contractility (increases the development of peak tension)

Question 16

How does the pressure change as blood goes from aorta, to the arterioles, to capillaries, to vena cava, to atria (the systemic CV system)

Answer 16

It decreases steadily (100mm Hg, 50, 20, 4, to 0-2mm Hg

Question 17

How does the systemic CV system mean pressure of blood flow compare with pulmonary system?

Answer 17

It is much higher

Question 18

activation of alpha adrenergic receptor would do what to arterioles of skin

Answer 18

vascular constriction

Question 19

activation of Beta-2 receptor on skeletal muscles would

Answer 19

vascular dilation

Question 20

nitroglycerine

Answer 20

vasodilator increases compliance and capacitance

Question 21

Increasing sympathetic tone causes smooth muscle contraction which does what to capacitance & compliance

Answer 21

decreases

Question 22

List the mean pressures in pulmonary system

Answer 22

pulmonary artery-15, capillaries-10, pulm. vein-8, left atrium-2-5

Question 23

cardiac murmur of aortic stenosis would be caused by these 2 things:

Answer 23

increased velocity of flow and non-laminar flow

Question 24

What accounts for the autonomic nervous systems control on heart rate i.e. which part in the conduction system does it effect?

Answer 24

Stage 4 depolarization of the SA node; Beta1 sympathetic makes it steeper (shift left) and parasympathetic makes flatter (shifts rt)

Question 25

What is the reason for the delayed AV nodal impulse?

Answer 25

allows for atria to pump blood into ventricle

Question 26

List the latent pacemakers and their intrinsic firing rates/min

Answer 26

SA node 70-80. AV node 40-60

Bundle of His 40 and Purkinje 15-20

Question 27

when would you see latent pacemakers take over?

Answer 27

vagal tone and “heart block”

Question 28

What does the amount of Ca++ released from the sarcopasmc reticulum in heart cells depend on?

Answer 28

the inward current of Ca++

Question 29

What is the difference between sympathetic stimulation on positive inotropy of heart vs. parasympathetic stim. on negative inotropy

Answer 29

Sympathetic innervates both atria & ventricle

Parasymp. only innervates ATRIA!

Question 30

What are some causes of negative inotropy

Answer 30

acidosis, myocardial ischemia, and cardiomyopathies

Question 31

what is post extra systolic potentiation

Answer 31

the beat following an extra systole exhibits potentiation (increased contractility)

Question 32

ejection fraction

Answer 32

% of blood in ventricle at end of diastole, ejected with a single beat (normal ejection is 55%)