Exam 1, kaplan USMLE topics

Question 1

How do you calculate CO

Answer 1

HR x SV

Question 2

How do you calculate MAP with just BP levels

Answer 2

DBP+ 1/3(SBP-DBP)

Question 3

what is formula for MAP

Answer 3

CO x TPR

Question 4

Which level of heart volume is the best representation of preload

Answer 4

EDV

Question 5

how do we measure increased preload of L ventricle

Answer 5

rise in pulmonary capillary wedge pressure

Question 6

What is the formula for ejection fraction

Answer 6

SV / EDV

Question 7

What can cause an increase in afteroload

Answer 7

increased MAP
increased TPR
aortic stenosis

Question 8

describe effects of increased afterload on SV and ESV

Answer 8

decreased SV

increased ESV

Question 9

describe changes with CHF on preload

Answer 9

loss of contractility which decreases ejection fraction and so increases preload

Question 10

describe changes in preload with hemorrhage

Answer 10

decrease preload, lose venous return

SAN responds to increases contractility

Question 11

what occurs with preload when you lay supine after standing

Answer 11

increased VR will increase performance and CO which inc BP so reflex is decreased SAN and reduced contractility

Question 12

What is the formula for SV

Answer 12

EDV-ESV

Question 13

what can cause an increase in ESV

Answer 13

abrnormal reduction in ventricular emptying due to impaired contractility or excessive afterload

Question 14

what can cause a an decrease in EDV

Answer 14

decrease in ventricular compliance during filling

tissue stiffness or impaired ventricular relaxation

Question 15

describe the process from which HTN can lead to L ventricular hypertrophy

Answer 15

at the begining the heart just increases contractility, over time preload increases, and decreased CO occurs. The ventricle then starts to hypertrophy to normalize wall tension

Question 16

how does radius affect the wall tension and ventricular pressure

Answer 16

as radius increases, more wall tension is needed to maintain pressure

Question 17

how do we calculate blood flow

Answer 17

Change in pressures over capillary bed (MAP-Venous Pressure) divided by Resistance

Question 18

where is the lowest pressure drop in vasculature of the body

Answer 18

over the arterioles

Question 19

how does blood viscosity affect resistence and how do we measure that? give clinical examples of dec viscosity and increased

Answer 19

increased viscosity increased Resistance
Hct!!
dec- anemia
inc- polycythemia vera

Question 20

how does length of a vessel affect R

Answer 20

proprtionate

2x length= 2x resistance

Question 21

what does a bruit indicate

Answer 21

turbulent flow

Question 22

what are factors that can increase turbulent flow

Answer 22

increased tube diameter, increased velocity and decreasing blood viscosity

vessel branching and stenosis

Question 23

how are afterload and CO paired

Answer 23

increased afterload usually causes a decrease in CO

Question 24

Right atrial Pressure is an indicator of what

Answer 24

preload

Question 25

describe changes in arterial and venous pressures from head to toe standing up

Answer 25

same pressure difference whole way.

as descend below the heart, both pressures increase

Question 26

what are the effects of SAN on the body

Answer 26

arteriolar vasoconstriciton
increase in HR
venoconstriction

Question 27

what is pulse pressure

Answer 27

difference of systolic and diastolic BP

Question 28

What is the formula for myocardial O2 consumption

Answer 28

MVO2= coronary blood flow, or CO x (AO2-VO2)

Question 29

What are the 2 main mechanisms involved in autoregulation of blood flow

Answer 29

metabolic: vasodilatory effects like adenosine, CO2, H+, and K+
myogenic: increased perdusing pressure increasing stretch so reflex contraction and decreased radius to decrease flow

Question 30

How does exercising skel muscle increase the O2 availability from icnreased demand

Answer 30

vasodilator metabolites

muscle pump

Question 31

when is coronary blood flow at its highest?

Answer 31

diastole becuase systole causes compression on vessels