Chapter 12 (Part 2) Flashcards Preview

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Flashcards in Chapter 12 (Part 2) Deck (51)
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1
Q

Unequal charge distribution

A

Resting membrane potential

2
Q

ECF has a high concentration of…

A

sodium ions

3
Q

ICF has a high concentration of..

A

potassium ions and negative charged proteins

4
Q

What is the resting potential of a neuron

A

-70mV

5
Q

Created by uneven concentration of the molecules across the membrane

A

Chemical gradient

6
Q

Created by the attraction between opposing chargesand repulsion from similar charges

A

Electrical gradient

7
Q

Actively move molecules against its gradient

A

Pumps

8
Q

What are the 2 pumps involved in the nervous system?

A

Na-K and calcium ion pump

9
Q

Always open allowing ions to diffuse across the plasma membrane

A

Leak channels

10
Q

Stimuli causes channels to open which changes the transmembrane potential

A

gated channels

11
Q

Open/close when bound with specific chemicals

A

Chemically gated

12
Q

Where are chemically gated channels found?

A

Soma, dendrite, muscle effectors

13
Q

Open/close in response to change in transmembrane potential

A

Voltage-gated

14
Q

Where are voltage gated channels found?

A

Membranes that generate action potentials

15
Q

Open/close as a result of physical stimulation

A

Mechanically gated

16
Q

Where are mechanically gated channels found?

A

Sensory receptors

17
Q

Localized change in transmembrane potential

A

Graded potential

18
Q

Change in transmembrane potential from a smaller negative value or positive value

A

Depolarization

19
Q

What is depolarization caused by?

A

Na+ ions rushing into cell

20
Q

Return to resting transmembrane potential

A

Repolarization

21
Q

What is repolarization caused by?

A

Closing Na+ channels and opening K+ channels to let K+ out of the cell

22
Q

Change in transmembrane potential making the cell more negative

A

Hyperpolarization

23
Q

What is hyperpolarization caused by?

A

Opening K+ (let out K+) and Cl- channels (let Cl- in)

24
Q

Change in transmembrane potential that once initiated spread through the entire membrane

A

Action potential

25
Q

What is the threshold membrane potential?

A

-55mV

26
Q

If threshold is met, an action potential will be sent down, if it’s not at -55mV, no action potential is sent

A

All-or-none law

27
Q

Membrane incapable of sending another action potential at this time

A

Absolute refractory period

28
Q

Membrane can send another action potential, but with only a large enough stimulus

A

Relative refractory period

29
Q

What are the 2 modes of action potential transmission?

A

Continuous propagation, saltatory propagation

30
Q

Where does continuous propagation happen?

A

Unmyelinated axons

31
Q

Where does saltatory propagation happen?

A

Myelinated axons

32
Q

AP moves in tiny steps along the axolemma

A

Continuous propagation

33
Q

Ions cross membrane at nodes

A

Saltatory propagation

34
Q

The larger the diameter the _____ AP propagation

A

Faster

35
Q

Uses ATP to re-establish resting chemical gradients

A

Sodium potassium exchange pumps

36
Q

Pups out ___ for every ___ brought back in

A

3 Na+, 2 K+

37
Q

Site where neuron communicates with another cell

A

Synapse

38
Q

Presynaptic and postsynaptic membranes are locked together with gap junctions

A

Electrical synapse

39
Q

Axon terminal releases neurotransmitters to communicate with postsynaptic cell

A

Chemical synapse

40
Q

What is the most common type of synapse?

A

Chemical

41
Q

Cell sending signal

A

Presynaptic cell

42
Q

Narrow space between cells where neurotransmitters are released

A

Synaptic cleft

43
Q

Cell receiving signal

A

Postsynaptic cell

44
Q

Graded potentials in postsynaptic membrane in response to a neurotransmitter

A

Postsynaptic potentials

45
Q

Cause localized depolarization making postsynaptic neuron closer to threshold

A

Excitatory postsynaptic potential

46
Q

What do excitatory potentials open?

A

Na+ channel

47
Q

Cause localized hyperpolarization making postsynaptic neurons further from threshold

A

Inhibitory postsynaptic potential

48
Q

What do inhibitory potentials open?

A

K+ or Cl- channels

49
Q

Integration of effect of graded potentials on the postsynaptic membrane

A

Summation

50
Q

Recurring activation of single synapse

A

Temporal summation

51
Q

When multiple synapses signal postsynaptic membrane simultaneously their effects on transmembrane potential are cumulative

A

Spatial summation