Unit 3 Exam Lab 9 Flashcards

1
Q

The source of calcium in skeletal muscle is:

A

the sarcoplasmic reticulum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

The source of calcium in cardiac muscle is:

A

the sarcoplasmic reticulum and extracellular sources

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The means of excitation for skeletal muscle is:

A

nervous system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

The means of excitation for cardiac muscle is:

A

inherent contractions initiated by pacemaker cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Innervation of skeletal muscle is through

A

Somatic Nervous System

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Innervation of cardiac muscle is through

A

Autonomic Nervous System

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The length of the refractory period in skeletal muscle is approximately:

A

2-3 msec

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The length of the refractory period in cardiac muscle is approximately:

A

200 msec or more

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Which ion is responsible for the long plateau phase of the ventricular muscle action potential?

A

Calcium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

The long plateau phase of the fast response action potential of cardiac muscle:

-is responsible for long refractory period seen in cardiac muscle.
-prevents cardiac muscle from tetanizing
-allows the heart to serve as a pump because the ventricles have time to fill with blood before another contraction can be induced.
-keeps cardiac muscle in the depolarized state so another contraction cannot be initiated until the heart has had time to contract and refill.
-All of the above are true.

A

all of the above are true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

During the cardiac cycle, an extra systole can be induced by electrical stimulation during:

A

the relative refractory period

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

The SA-node is innervated by:

A

both the Parasympathetic and Sympathetic nervous systems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

The AV-node is innervated by:

A

both the Parasympathetic and Sympathetic nervous systems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

The atria are innervated by:

A

both the Parasympathetic and Sympathetic nervous systems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

The ventricles are innervated by:

A

Sympathetic nervous system only

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The ______ Nervous System increases the intracellular Ca++, which permits a more rapid & forceful contraction, _____ the rate of re-uptake of Ca++ by sarcoplasmic reticulum following contraction, which _____ plateau phase of ventricular fast response action potential or QT interval making it possible to cause a _____ heart rate.

A

Sympathetic; increases; shortens; faster

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Which of the following statements is/are true?
Group of answer choices

Decreasing the temperature of the fluid bathing the pacemaker caused a decreased rate of contraction and increased stroke volume.

Increasing the temperature of the fluid bathing the pacemaker caused a decreased rate of contraction and increased stroke volume.

Altering only the temperature of the fluid bathing the heart does not affect overall metabolic needs of an organism.

If overall metabolic needs of an organism are not affected, there is no need for CO to increase or decrease.

A

Decreasing the temperature of the fluid bathing the pacemaker caused a decreased rate of contraction and increased stroke volume.

Altering only the temperature of the fluid bathing the heart does not affect overall metabolic needs of an organism.

If overall metabolic needs of an organism are not affected, there is no need for CO to increase or decrease.

18
Q

Decreasing the temperature of the fluid bathing the sinus venosus:

A

-Decreases HR
-Decreases diffusion rate
-Prepotential slope becomes shallower
-Follows Fick’s Law

19
Q

Increasing the temperature of the fluid bathing the sinus venosus:

A

-Increases HR
-Increases diffusion rate
-Prepotential slope becomes steeper
-Affects Fick’s Law

20
Q

Stimulation of the right vagus nerve innervating the turtle heart:

A

causes the heart rate to decrease

21
Q

Which of the following statements are true for both increasing the temperature of the fluid surrounding the sinus venosus and stimulating the heart with epinephrine?

A

Heart rate increases

Filling time decreases.

21
Q

Vagal stimulation following the addition of atropine results in

A

no change in the heart rate

22
Q

During the cardiac cycle, an extra systole can be induced by electrical stimulation during:

A

the relative refractory period.

23
Q

relative refractory period

A

supra-threshold stimuli can result in a muscle contraction

24
Q

absolute refractory period

A

no stimulus (no matter how strong) can stimulate muscle to contract during this time

25
Q

non-refractory

A

muscle is in polarized state

26
Q

The compensatory pause is seen because:

A

the wave of depolarization from the sinus venosus reaches the ventricular muscle during the absolute refractory period of the extra-systole.

27
Q

You are given a turtle heart preparation with the Stannius Ligatures I and II tied properly. You count the ventricular rate and find it to be 12 beats per minute. Based on what you’ve learned, what rates might you expect to find for sinus venosus and atria, respectively?

A

20 beats/min, 15 beats/min

28
Q

Stannius Ligature I

A

between sinus venosus and atria

29
Q

Stannius Ligature II

A

between atria and ventricle

30
Q

When Stannius Ligatures I and II are tied on a turtle heart, the ______ the lowest (shallowest) prepotential slope, the ______ an intermediate prepotential slope and the ______ the greatest (steepest) prepotential slope.

A

ventricles have; atria have; sinus venosus has

31
Q

The two systems of control over cardiac function are Autoregulation via Einthoven’s Law and the nervous system control via somatic nerves.

True or false

A

False

32
Q

simulates ventricular muscle cells by decreasing the rate of force development, rate of relaxation, and maximal force developed.

A

The parasympathetic nervous system

33
Q

stimulates ventricular muscle cells by increasing the rate of force development, rate of relaxation, and maximal force developed.

A

The sympathetic nervous system

34
Q

Vagal tone

A

Tonic stimulation by the Parasympathetic Nervous System of the SA-node.

35
Q

Cutting the right vagus nerve: (2)

A
  1. eliminates vagal tone
  2. causes heart rate to increase
36
Q
  • binding of large quantities of acetylcholine to cholinergic receptors in the sinus venosus.
    -continuing vagal stimulation until the heart stops beating
    -continuing vagal stimulation that causes the prepotential slope of action potentials in the sinus venosus to approach zero.
A

Vagal arrest

37
Q

Contraction phase

A

systole

38
Q

Filling/relaxing phase

A

diastole

39
Q

Result of stimulation during absolute refractory period

A

Compensatory period

40
Q

Prepotential of slow response action potential slope approaches zero

A

Vagal arrest

41
Q

Alternate pacemakers take over

A

Vagal escape