Brainscape's Knowledge GenomeTM

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


See full index

Physiology > Module 3: Lecture 4 > Flashcards

Module 3: Lecture 4 Flashcards

1
Q

True or False
Action potentials all have the same magnitude but the frequency effects how and what is cellularly communicated

A

True

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

What is the refractory period?

A

we are unable to generate a second action potential until the first one has completed

the time period in between

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

What are the 2 general phases of the refractory period?

A
  1. Absolute refractory period
  2. Relative refractory period
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the Absolute refractory period

A

period where we cannot generate a second action potential

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

What is the beginning to end of the Absolute refractory period

A

initial to resting membrane

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

What is the Relative refractory period?

A

where another action potential can occur, because the sodium channels have reset

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

How do we restore the original concentrations of sodium and potassium?

A

sodium/potassium ATPase pump

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

How does the sodium-potassium pump work?

A
  • the opening for the Na+/K+ pump is facing intracellularly
  • it has a very high affinity for sodium, it has a active site specifically for sodium which will bind to it
  • then we phosphorylate the pump, we bring in ATP and bind a phosphate group to the pump
  • as the phosphate uses its energy the protein membrane changes it’s opening to be extracellularly, which allows sodium ions to diffuse out
  • now the pump has a high affinity for potassium which it now binds to the specific potassium active sites
  • now the phosphate group will leave the pump, reverting the pump towards the inside of the cell allowing potassium to diffuse into the cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Is the sodium-potassium pump always “ON”?

A

Yasss

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

True of False
The sodium-potassium pump counterbalances the rate of passive leakage

A

True

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

Is the sodium-potassium pump an active or passive process?

A

primary active transport, it requires energy

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

What are the 4 zones of the nerve cell?

A
  1. Input zone
  2. Trigger zone
  3. Conducting zone
  4. Output zone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What happens in the input zone?
(dendrites and cell body)

A
  • where the cell receives all of its communications from other nerves
  • this is where all the graded potentials occur
  • it includes the cell body (has a nucleus) and dendrites (finger-like structure)
  • the message goes from the dendrites to the cell body to the trigger zone or axon hillock
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What happens in the trigger zone?
(Axon Hillocks)

A
  • where the action potentials are initiated
  • there is a high concentration of voltage-gated sodium and potassium channels
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What happens in the conducting zone?
(axon)

A
  • where an action potential is propagated
  • can be a long or a short distance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What happens in the output zone?
(axon terminals)

A
  • where the axon terminals are and they send off the continued messages
17
Q

what is the point of the dendrites?

A

they greatly increase the surface area, to receive multiple-cell communications

18
Q

What are the 2 methods of action potentials that will travel down the axon?

A
  1. Contiguous conduction
  2. Saltatory conduction
19
Q

How does the contiguous conduction work?

A
  • it uses the initial gated channels that reach the threshold to allow one action potential to occur
  • then once all the sodium is in the cell is travels along the membrane triggers more action potentials all the way down the axon
20
Q

True or False
The contiguous conduction is a self-perpetuating cycle that automatic

A

True

21
Q

Why does the action potential only travel in one directon?

A

due to refractory period

22
Q

What is saltatory conduction

A

action potentials will jump down patches due to myelinated fibers

23
Q

Are myelin sheets hydrophobic or hydrophilic?

A

hydrophobic, very good insulator

24
Q

what is the peripheral nervous cells?

A

nerve cells not including the spinal cord

25
Q

What are the central nervous cells?

A

nerve cells in the spinal cord

26
Q

How does myelination occur?

A

due to Schwann cells
- individuals cells wrap around the axon leaving a gap called the nodes of ranvier

27
Q

What are the nervous cells in the central nervous system called?

A

oligodendrocytes

28
Q

What are oligodendrocytes?

A

nerve cells with large bodies and foot-like projections

  • wrap multiple different axons in myelin sheath
29
Q

What is the point of having cells wrapped in myelinated sheath?

A
  • increases insulating effects increasing cell communication
30
Q

How long are the nodes of ranvier?

A

2 microns in length

31
Q

How often do node of ranvier occur? and why?

A
  • every millimeters or so
  • we need them because theres voltage-gated ion channels at the nodes for action potentials to occur

Physiology (26 decks)

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