BF/Hemodynamics, Cardiac Cycle

Question 1

COP=

Answer 1

SV*HR

Question 2

relationship between BP and flow

Answer 2

Q=P drop/R

Question 3

relationship between BP and TPR

Answer 3

P drop=CO*TPR

Question 4

fx contrib to resistance

Answer 4

R=8nl/(pi)r^4

Question 5

fx contrib to flow

Answer 5

Q=pressure drop(pi)r^4/8nl

Question 6

MAP

Answer 6

MAP=DBP+(1/3)(SBP-DBP)

Question 7

pulse pressure

Answer 7

SP-DP

Question 8

velocity and total cross sectional area

Answer 8

velocity dec with inc total cross sectional area

Question 9

How do capillaries withstand high P?

Answer 9

T=Pr (law of LaPlace)

Small vessels can withstand high P bc their radii are small – can maintain T (force needed to prevent wall from splitting)

Question 10

Swan-Ganz catheter

Answer 10

vein–> RA –> RV –> pulm A –> wedges into small vessel –> detects pulm wedge P (good indicator of LA P)

Question 11

ventricular systole begins when the ____ valve closes and ends when the ____ valve closes

Answer 11

mitral, aortic

Question 12

a wave

Answer 12

atrial systole

Question 13

c wave

Answer 13

atrial contraction

Question 14

x descent

Answer 14

atrial relaXation

Question 15

v wave

Answer 15

venous filling

Question 16

y descent

Answer 16

atrial emptying

Question 17

obtaining the SV from pressure-volume loop

Answer 17

WIDTH of the pressure-volume loop is the difference between EDV and ESV (=SV)

Question 18

area within the pressure-volume loop

Answer 18

ventricular stroke work (work done by ventricle to eject a vol of blood into the aorta)

Question 19

ESPVR curve

Answer 19

filling of the ventricle

gives the maximal pressure that can be developed under any given LV volume

Question 20

duration of systole vs diastole

Answer 20

duration of systole is ~1/3 cardiac cycle, while diastole is ~2/3

Question 21

systemic vs pulm BF

Answer 21

EQUAL although SVs can vary from beat to beat

Question 22

SV at rest

Answer 22

~70 ml

Question 23

EF=

Answer 23

SV/EDV

~55%

Question 24

events occurring almost simultaneously with onset of systole

Answer 24

• QRS complex
• S1
• c wave
• closure of mitral valve
• rise in ventricular P

Question 25

events occurring almost simultaneously with onset of diastole

Answer 25

• S2
• closure of aortic valve
• incisura
• drop in ventricular P

Question 26

the heart pumps its stroke volume between

Answer 26

S1 and S2