CV5 Cardiac Cycle and Vent Performance

Question 1

The heart accepts blood at ___ pressure during ____ and the propels it forward at ____ pressures during ____

Answer 1

low, dias, high, sis

Question 2

If cardiac output is intermittent how does tissue bloof flow remian relatively constant?

Answer 2

Distension of the aorta and its braches during systole and elastic recoil during diastole

Question 3

Stephen Hales

Answer 3

Drew the analogy b/w resistance and compliance elements of the CV to a windkessel reservoir

Question 4

Otto Frank

Answer 4

Formualted the two-element windkessel model consisting of a resistance and compliance element

Question 5

Cardiac cycle

Answer 5

Sequence of electrical and mechanical events that repeats with every heartbeat

Question 6

For a typical heart rate of ___ bpm the cardiac cycle has a total time of

Answer 6

75bpm, 0.8s

Question 7

What produces heart sounds?

Answer 7

opening and closing valves

Question 8

Stroke volue

Answer 8

The amount of blood pumped by the LV during one cardiac cycle

Question 9

Calculate SV

Answer 9

SV=LVEDV=LVESV

Question 10

Ejection fraction should exceed

Answer 10

SV/LVEDV
55% in a healthy person

Question 11

Greater venus return means __ filling pressure

Answer 11

greater

Question 12

Preload

Answer 12

Force that stretches the relaxed muscle fiber (end-diastolic volume)

Question 13

LVEDPtm = ____ - _____

Answer 13

LVEDPtm= LVEDP - pericardial pressure

Question 14

Frank-Starling “Law of the Heart”

Answer 14

SV increases in response to an increase in the volume of blood

Question 15

Inflow phase (Phase 1)

Answer 15

Mitral valve is open
Aortic valve is closed

Question 16

Isovolumic contraction

Answer 16

Both valves closed - no flow

Question 17

Outflow phase

Answer 17

Mitral valve closed
Aortic valve open

Question 18

Isovolumic relaxation

Answer 18

Both valves closed no flow

Question 19

Phase 1 - Inflow

Answer 19

Diastole (passive and active)
Mitral valve open - Aortic valve closed
Rapid vent filling
Diastasis - decreased vent filling
Atrial cont - vent filling

Question 20

Phase 3 (Outflow)

Answer 20

Systole
Mitral valve closed - aortic valve open
Rapid vent ejection
Decreased vent ejection

Question 21

Phase 4

Answer 21

Diastole
Both valves closed

Question 22

Cardiac cycle

Answer 22

seq of elctrical and mech events

Question 23

Cardiac reserve

Answer 23

The difference b/w a person’s max output and output at rest

Question 24

Preload

Answer 24

Force that stretches the relaxed muscle fiber (EDV)

Question 25

What determines the preload?

Answer 25

Venous return and filling time

Question 26

The load the vent faces before it contracts EDV

Answer 26

preload

Question 27

Normal EDV is ____ mL and is optimal because

Answer 27

120, optimal overlap of actin and myosin in sarcomere

Question 28

Frank-Starling law of the heart

Answer 28

stroke volume increases in response to an increase in the volume of blood filling the heart when all other factors remain constant

Question 29

Contractility

Answer 29

Cardiac performance at a given preload and afterload (ejection fraction) Rate of pressure development (P/t)

Question 30

When we exercise we have ___ ___ of contractility

Answer 30

increased force

Question 31

Afterload

Answer 31

The load the vent faces before it begins to contract (aortic pressure)