Brainscape's Knowledge GenomeTM

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


See full index

Comparative Animal Physiology Exam 1 > Excitable Membranes and potential gradients > Flashcards

Excitable Membranes and potential gradients Flashcards

1
Q

What are the four factors that establish the cell membrane resting potential?

A
  1. membrane permeability
  2. solute concentration gradients
  3. electrical conc gradients
  4. active molecular pumps
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What does the Nerst equation assume to be zero?

A

Net flux

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

What are fixed anions?

A

negatively charge large mol that cannot leave the inside of the cell and exert a net negative source on the inside of the cell

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

Give an example of Donnan Equilibrium.

A

The net negative charge inside the cell pulls in K+ against its concentration gradient. At equilibrium the concentration of K+ is 20 times greater inside than outside.

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

Three features of active molecular pumps

A
  1. tansport can take place against a concentration gradient
  2. Transport is selective
  3. Use ATP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

WHat is transported where in the sodium potassium pump?

A

3 sodium of and 2 potassium in

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

The charged ions moving through the electrolyte solution ie the cell membrane create a what?

A

constant current called a riogenic current

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

What is electrotonis?

A

the natural electrical resting state of the cell

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

What are the four physiological ions?

A

Na K Cl Ca

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

Cell membranes high permeability to what ion?

A

K

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

Cell membranes are not permeable to what ions?

A

Na Cl Ca

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

Sodium and chloride are how many times more concentrated on the outside than inside?

A

10 times

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

Calcium is how many orders of magnitude greater on the outside than inside?

A

2-7

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

What is the resting membrane potential?

A

-60mV to -70mV

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

What are the three types of tissue that have excitable membranes?

A

muscle
nervous
epithelial

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

What are the two fundamental states of excitable membranes?

A

resting and active

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

WHat does the Goldman adjustment take care of?

A

The Nerst equation for the trans membrane potential does not take into account all the ions in an excitable membrane. the Goldman adjustment specifically includes the permeability of Na and Cl and established the trans membrane potential as -60mV

18
Q

What is the primary ion involved in creating an action potential?

A

Na

19
Q

What is depolarization?

A

The complete reversal of charge of the inside to the outside of the cell from the effects of the membrane being permeable to Na for only a few microseconds.

20
Q

What does a Na equilibrium across the membrane establish?

A

an Action Potential

21
Q

Cll membranes designed to close quick or slow and what is this phenomenon known as?

A

ball and chain close fast!

22
Q

How is sodium permeability controlled?

A

When a nerve is stimulated and depolarization occurs the sodium channels are only open for a very short period of time and only a few ions are allowed to cross through and only a few are needed to create an action potential so that the nerve can repolarize faster!

23
Q

How does the membrane become permeable to sodium?

A

gated channels are opened

24
Q

what are the three types of gated channels?

A

ligand gated channels
voltage geted channels
mechanically gated channels

25
Q

What are mechanically gated channels?

A

The cell membrane is distorted and that deformation allows the Na to come in.
Good in stretch receptors on skin or joints. pressure sensors too.

26
Q

What is the ligand gated channel?

A

Have specific receptors for certain types of molecules and when it comes in contact with that molecule the gate opens. Nerve Tracks

27
Q

What are voltage gated channels?

A

It is the flow of a charged molecule that creates the amperage. When there is enough flow of ions the voltage gate will open.

28
Q

What type of channel do we use the most?

A

voltage gated channels

29
Q

When Na flows through ligand gated channels what other gates are opened?

A

voltage gated channels by the flow of the charged molecules

30
Q

What is an action potential?

A

self propagating way of depolarization in a preferred direction.

31
Q

What cycle can illustrate the series of events that take place during a depolarization?

A

Hodgkin’s Cycle

32
Q

What are the events that are shown in the action potential?

A

sodium channels activated, overshoot, sodium channels deactivate, rectified potassium channels activate, hyper polarization

33
Q

WHat is a local response?

A

A response that causes a little movement of ions but not enough to trip the voltage gates. Membrane reestablished itself almost instantly.

34
Q

What is threshold value?

A

Once you reach threshold response cannot stop what happens it all relies on the membrane potential. Voltage gates open and reach 0 V and goes beyond to overshoot.

35
Q

Why does the membrane over shoot the 0V?

A

Because there is a concentration and electrical gradient. Jaust because the electrical gradient is in equilibrium does not mean the concentration is in equilibrium as well.

36
Q

At what voltage do the sodium gates close?

A

+55mV

37
Q

WHat are the rectified potassium channels?

A

Specialized gates in cell membrane that allow potassium to move out faster to restore negative inside to outside relationship for another action potential to occur.

38
Q

From the time threshold is reached to the time where the tangent on curve shifts another action potential will not be generated what is this point called?

A

absolute refractory period

39
Q

Relative refractory period?

A

period where you can send another action potential but you must have a much stronger signal strength.

40
Q

What is Accommodation?

A

slow gradual application of stimulus and therefore need a higher threshold…threshold event is changeable

41
Q

What is adaptation? what is a better term for this?

A

Constant stimulus in certain neurons will cause a decrease in the frequency of depolarization. A better term would be habituation. ex puppy with color

Comparative Animal Physiology Exam 1 (6 decks)

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