Cardio 2

Question 1

99% of myocardium

Answer 1

contractile cells

Question 2

contractile cells depolarized by

Answer 2

signal fom AR cells

Question 3

phases of action potential

Answer 3

4
0
1
2
3

Question 4

Phase 4 –

Answer 4

Resting Vm

Question 5

Phase 0 –

Answer 5

Depolarization spike
Fast voltage gated Na+ channel
(activation/inactivation gates) open

Question 6

Phase 1 –

Answer 6

Partial Repolarization

Fast voltage gated Na+ channel close

Question 7

Phase 2 -

Answer 7

plateau
Transient K+ channels close
L-Type Ca++ channels open

Question 8

Phase 3 –

Answer 8

Repolarization
L-Type Ca++ channels close
Slow K+ channels open

Question 9

In skeletal muscle, Contractile response to a single AP is

Answer 9

all or
none – Ca++ released saturates troponin and contraction
strength is maximal.

Question 10

In Cardiac muscle, contractile response to a single AP is

Answer 10

graded

Question 11

In “resting” state, AP-induced sarcoplasmic release of Ca++ in cardiac cells does not saturate — sites.

Answer 11

troponin

Question 12

Strength of contraction depends on

Answer 12

[Ca++]i

Question 13

[Ca++]i is adjusted to increase — of contraction.

Answer 13

strength

Question 14

Substances that alter the force of contraction of cardiocytes by
changing [Ca++]cytosol are termed

Answer 14

inotropic agents

Question 15

Inotropic

agents change

Answer 15

contractility of the heart (how forcefully the

cells contract). Ex. Sympathetic NS/Epinephrine

Question 16

The cardiac cycle includes all the events involved with

Answer 16

blood flow through the heart during one heart beat

Question 17

Blood flows down

Answer 17

ΔP

Question 18

Valves open and close passively due to

Answer 18

ΔP

Question 19

Events of the cardiac cycle

Answer 19

1. Between Beats – Passive Filling
2. Atrial systole – Active filling
3. Atrial Diastole/Early Ventricular Systole - Isovolumetric
   Contraction
4. Late Ventricular Systole – Ejection phase
5. Early Ventricular Diastole – Isovolumetric Relaxation
6. Late Ventricular Diastole

Question 20

Between Beats (4)

Answer 20

Pressure A < Pressure Veins
Pressure A > Pressure V
Pressure V < Pressure Arteries

Question 21

1. Between Beats: referred to as

Period of

Answer 21

Passive Filling
80% of Blood for contraction loaded into
ventricles at this time.

Question 22

2. Atrial Systole (4)

Answer 22

Pressure A incease
Pressure A > Pressure Veins
Pressure A > Pressure V
Pressure V < Pressure Arteries

Question 23

2. Atrial Systole: referred to as

Period of

Answer 23

Active Filling
20% of Blood for contraction loaded into
ventricles at this time.

Question 24

3. Atrial Diastole/Early Ventricular Systole (5)

Answer 24

Pressure A decrease
Pressure V incease
Pressure A < Pressure Veins
Pressure A < Pressure V
Pressure V < Pressure Arteries

Question 25

3. Atrial Diastole/Early ventricular Systole: referred to as
   Period of

Answer 25

Isovolumetric Contraction

Pressure in V increases

Question 26

4. Late Ventricular Systole (4)

Answer 26

Pressure A < Pressure Veins
Pressure A < Pressure V
Pressure V > Pressure Arteries

Question 27

4. Late VEntricular Systole: referred to as

Answer 27

Ejection Phase
Equal volume of blood ejected into both
circulations

Question 28

5. Early Ventricular Diastole (4)

Answer 28

Pressure V decrease
Pressure A < Pressure Veins
Pressure A < Pressure V
Pressure V < Pressure Arteries

Question 29

5. Early Ventricular Diastole: referred to as

Period of

Answer 29

Isovolumetric Relaxation

Pressure in V decreases

Question 30

6. Late Ventricular Diastole (5)

Answer 30

Pressure A < Pressure Veins
Pressure A > Pressure V
Pressure V < Pressure Arteries

Question 31

During 6. Late Ventricular Diastole, what begins?

Answer 31

Period of Passive Filling Begins

Question 32

Pressure/Volume Loop

Answer 32

Δ in Left Ventricular Volume and Pressure

Question 33

1. End Diastolic Volume (EDV)

Answer 33

≈ 135 ml

Question 34

2. End Systolic Volume (ESV)

Answer 34

≈ 65 ml

Question 35

3. Stroke Volume (SV)

Answer 35

=volume of blood ejected/beat
=EDV-ESV
≈70ml/beat

Question 36

4. Ejection Fraction

Answer 36

Fraction of EDV ejected/beat
=SV/EDV
≈52%

Question 37

Heart Sounds (lub dub)
 Due to

Answer 37

Valve closures

Question 38

Heart Murmurs

Answer 38

 Abnormal heart sounds

Question 39

stenosis

Answer 39

failure of valves to open completely

Question 40

insufficiency or prolapse

Answer 40

failure of valves to close properly