Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Physiology Exam 1 Semester 1 > Lecture 7 > Flashcards

Lecture 7 Flashcards

1
Q

What are the special requirements of cardiac action potential?

A
  1. Must be self generating
  2. Must be prolonged
  3. Propagate from myocyte to myocyte
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

In terms of cardiac muscle action potential phase 4 is what?

A

Resting potential

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

In terms of cardiac muscle action potential phase 0 is what?

A

Rapid depolarization

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

In terms of cardiac muscle action potential phase 1 is what?

A

initial, incomplete repolarization

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

In terms of cardiac muscle action potential phase 2 is what?

A

Plateau or slow decline of membrane potential

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

In terms of cardiac muscle action potential phase 3 is what?

A

Repolarization

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

What are the characteristics of fast type contractile myocytes? What is an example?

A
  • Large Diameter
  • High Amplitude
  • Rapid onset of action potential
    EXAMPLE: Ventricle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the characteristics of fast type non-contractile myocytes? What is an example?

A
  • Very large diameter
  • Very rapid upstroke
    EXAMPLE: Purkinje Fibers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the characteristics of slow type non-contractile myocytes? What is an example?

A
  • Small diameter
  • Low amplitude
  • Slow rate of depolarization
    EXAMPLE: SA or VA node
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is it called when it is impossible to generate another action potential?

A

Absolute Refractory Period

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

What is it called when a stronger than normal stimulus can generate an action potential?

A

Relative Refractory Period

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

The triceps muscle while lowering down into the floor during pushup is eccentric or concentric?

A

Eccentric

  • Pull up:
    Triceps: UP: Eccentric DOWN: Concentric
    Biceps: UP: Concentric DOWN: Eccentric
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What maintains optimum calcium concentration gradient to facilitate return of calcium to SR?

A

Calsequestrin

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

What happens after ATP binds to the myosin?

A

Release of the myosin head from the actin binding site.

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

What is the order of the make up of a muscle? Start with muscle –>

A

Muscle–> fasicle –> myofibers –> myofibrils –> actin and myosin

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

What makes up a sarcomere?

A

Actin and myosin (myofilaments)

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

Long chain or sarcomeres is what?

A

Myofibrils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What does not go with change in length during a contraction?

A

A band

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What bands are composed entirely of actin filaments?

A

I band

20
Q

DHP is composed of what?

A

T tubules

21
Q

What causes an action potential in the ventricular fiber action potential?

A

Opening of fast sodium channels and slow calcium sodium channels

22
Q

Source of calcium necessary for electrical mechanical coupling from the T tubules via diffusion through voltage dependent calcium channels is called what?

A

Dihydropyridine receptors

23
Q

L type calcium channels are found in the t tubule membrane are called what?

A

Dihydropyridine receptors

24
Q

During the absolute refractory period is it impossible to generate another action potential? T or F

A

True it is impossible

25
Q

During the relative refractory period what can generate an action potential?

A

A stronger than normal stimulus.

26
Q

What is considered the pacemaker of the heart?

A

SA node

27
Q

The resting membrane potential of SA node fiber are fast sodiums channels that are already what?

A

inactivated (block)

28
Q

If only slow sodium calcium channels can open the atrial node action potential is what? And repolarization is what?

A

Is slower to develop with slower repolarization

29
Q

At resting potential the membrane potential approaches what?

A

K+ equil. potential.

30
Q

Action potentials originating in the SA node generates what?

A

A sinus rhythm

31
Q

Compared to skeletal muscle cardiac muscle has far fewer what?

A

calcium induced calcium release channels

32
Q

What are the two transporters for relaxation?

A

SERCA and sodium calcium exchange in the sarcolemma

33
Q

What is SERCA and what does it do?

A

Sarcoplasmic reticulum calcium ATPase, return calcium to the sarcoplasmic reticulum during diastole

34
Q

What does the sodium calcium exchanger in the sarcolemma do?

A

Transport calcium out of the cell.

35
Q

What valves are closed during systole?

A

AV valves

36
Q

What happens at the end of ventricular systole?

A

AV valves open at the end of systole because of increased pressures in the atria

37
Q

What happens in atria as a primer pump?

A

About 80% of blood flows from the atria to the ventricles before the atria contract

38
Q

What happens during the first third diastole?

A

Rapid filling

39
Q

What happens during the middle third of diastole (diastasis)

A

Small amount of blood flows into the ventricles representing blood that continues to flow into atria during diastole

40
Q

What happens in the last third of diastole?

A

Atria contract to push last 20% of blood into the ventricles

41
Q

What happens in isometric contraction?

A

Ventricles contract but semilunar valves do not open

42
Q

What happens during the period of rapid ejection?

A

Occurs when left ventricular pressure is a little above 80mmHg, semilunar valves open, occurs during the first third of ejection

43
Q

What happens during the period of slow ejection?

A

Remaining 30% of blood is ejected from the ventricles, occurs during the last two-thirds of ejection

44
Q

What are the Frank-Starling Law?

A

The greater the heart muscle is stretched during filling, the greater the force of contraction and the greater the quantity of blood pumped into the aorta

45
Q

What does the stretching of the cardiac muscle do?

A

Brings the actin and myosin filaments to a more nearly optimal degree of overlap for force generation

Physiology Exam 1 Semester 1 (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions