Brainscape's Knowledge GenomeTM

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


See full index

CSB335 > Cardiac muscle and electrophysiology > Flashcards

Cardiac muscle and electrophysiology Flashcards

1
Q

What is the sarcolemma?

A

The cell membrane that encloses the cardiomyocyte

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

The sarcoplasm contains the ____.

A

Organelles

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

T tubules are like a collecting duct system where the ____ is stored.

A

Calcium

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

Are T tubules intra- or extracellular?

A

Extracellular, though they do delve into cells

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

What is the function of intercalated disks?

A

Hold cardiomyocyte cells together and allows them to communicate in a mechanical sense

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

The sarcomere is the ____ ____ of cardiac muscle

A

Contractile element

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

The Z line to Z line is the…

A

Length of a sarcomere

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

What are the two filaments of cardiac muscle?

A

Actin and myosin

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

True or false: branching is not typical of cardiomyocytes

A

False

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

True or false: cardiomyocytes typically have only 1 or 2 nuclei

A

True

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

What are gap junctions?

A

The electrical or chemical connects between the cells

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

Desmosomes act as an ____ to keep the muscles from ____.

A

Anchor

Tearing

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

Why are cardiomyocytes resistant to fatigue?

A

Lots of mitochondria

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

Which is the thin filament?

A

Actin

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

Do the filaments themselves contract with the muscle?

A

No, just move between each other

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

Which is the thick filament?

A

Myosin

17
Q

Troponin is a ____ ____.

A

Cardiac enzyme

18
Q

Which ion causes contraction?

A

Calcium

19
Q

What does calcium bind to in cardiomyocyte contraction?

A

Troponin C

20
Q

What are the two types of cells throughout the myocardium?

A

Pacemaker cells (also called nodal cells) and cardiomyocytes

21
Q

Where are pacemaker cells found in the heart?

A
  • SA node
  • AV node
  • Bundle of His
  • Perkinje fibres
22
Q

What particular quality do pacemaker cells possess?

A

Automaticity - they depolarise themselves.

23
Q

Do pacemaker cells have a higher or lower resting membrane potential than cardiomyocytes?

A

Higher, making it easier to depolarise

24
Q

What is threshold potential?

A

Minimum voltage required to open the ion channels required to cause depolarisation

25
Q

What occurs in phase 4 of depolarisation?

A

Cell is at resting membrane potential, K is inside the cell, Na and Ca are outside the cell.

26
Q

What occurs in phase 0 of depolarisation?

A

Na channels open and Na starts coming into the cell. The cell hits threshold potential and voltage-gated channels open for Na to flood in.

27
Q

What occurs in phase 1 of depolarisation?

A

K channels open and K leaves the cell

28
Q

What occurs in phase 2 of depolarisation?

A

Ca channels open and Ca starts flowing into the cell, causing a plateau as it counteracts the exiting K

29
Q

What occurs in phase 3 of depolarisation?

A

Na/K ATPase pump pulls K back into the cell and pushed Na and Ca out in order to return to resting state

30
Q

Summarise the action potential phases

A

4: K+ ions enter cell and Na+ echange via Na/K pump
0: Rapid Na+ influx
1: K+ Cl efflux
2: Ca2 influx and K+ efflux
3: K+ efflux

31
Q

Describe the absolute refractory period

A

The time period during which the cell will not respond to further stimulation

32
Q

Describe the relative refractory period

A

Vulnerable period; some cardiac cells have repolarised and can be stimulated to respond to a stronger than normal stimulus

33
Q

Describe the flow of electricity through the heart

A

SA node in the RA sets the pace -> goes through Bachmann’s bundle to the LA -> moves down intranodal tracks and terminates at AV node (rate limiting step — sets conduction delay) -> comes down to Bundle of His -> splits into L and R bundle branch (L bundle branch has two fascicles, anterior and posterior) -> moves into Purkinje fibres around the ventricles

34
Q

In a normal heart the SA node fires at a rate of ____ to ____ per minute

A

60 to 100

35
Q

What is the effect of inotropes?

A

Increased force of contraction

36
Q

What is an example of an inotrope?

A

Adrenaline

37
Q

What effect does more adrenaline have on the heart?

A

More Na and Ca moving into cells, resulting in a faster HR and stronger contraction

38
Q

What effect does more acetylcholine have on the heart?

A

Less Na and Ca moving into cells, resulting in a slower HR and decreased force of contraction

CSB335 (12 decks)

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