Chapter 12 (Part 2) Flashcards Preview

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

Unequal charge distribution

Resting membrane potential

2

ECF has a high concentration of...

sodium ions

3

ICF has a high concentration of..

potassium ions and negative charged proteins

4

What is the resting potential of a neuron

-70mV

5

Created by uneven concentration of the molecules across the membrane

Chemical gradient

6

Created by the attraction between opposing chargesand repulsion from similar charges

Electrical gradient

7

Actively move molecules against its gradient

Pumps

8

What are the 2 pumps involved in the nervous system?

Na-K and calcium ion pump

9

Always open allowing ions to diffuse across the plasma membrane

Leak channels

10

Stimuli causes channels to open which changes the transmembrane potential

gated channels

11

Open/close when bound with specific chemicals

Chemically gated

12

Where are chemically gated channels found?

Soma, dendrite, muscle effectors

13

Open/close in response to change in transmembrane potential

Voltage-gated

14

Where are voltage gated channels found?

Membranes that generate action potentials

15

Open/close as a result of physical stimulation

Mechanically gated

16

Where are mechanically gated channels found?

Sensory receptors

17

Localized change in transmembrane potential

Graded potential

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

Depolarization

19

What is depolarization caused by?

Na+ ions rushing into cell

20

Return to resting transmembrane potential

Repolarization

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What is repolarization caused by?

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

22

Change in transmembrane potential making the cell more negative

Hyperpolarization

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What is hyperpolarization caused by?

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

24

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

Action potential

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What is the threshold membrane potential?

-55mV

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

All-or-none law

27

Membrane incapable of sending another action potential at this time

Absolute refractory period

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

Relative refractory period

29

What are the 2 modes of action potential transmission?

Continuous propagation, saltatory propagation

30

Where does continuous propagation happen?

Unmyelinated axons

31

Where does saltatory propagation happen?

Myelinated axons

32

AP moves in tiny steps along the axolemma

Continuous propagation

33

Ions cross membrane at nodes

Saltatory propagation

34

The larger the diameter the _____ AP propagation

Faster

35

Uses ATP to re-establish resting chemical gradients

Sodium potassium exchange pumps

36

Pups out ___ for every ___ brought back in

3 Na+, 2 K+

37

Site where neuron communicates with another cell

Synapse

38

Presynaptic and postsynaptic membranes are locked together with gap junctions

Electrical synapse

39

Axon terminal releases neurotransmitters to communicate with postsynaptic cell

Chemical synapse

40

What is the most common type of synapse?

Chemical

41

Cell sending signal

Presynaptic cell

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Narrow space between cells where neurotransmitters are released

Synaptic cleft

43

Cell receiving signal

Postsynaptic cell

44

Graded potentials in postsynaptic membrane in response to a neurotransmitter

Postsynaptic potentials

45

Cause localized depolarization making postsynaptic neuron closer to threshold

Excitatory postsynaptic potential

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What do excitatory potentials open?

Na+ channel

47

Cause localized hyperpolarization making postsynaptic neurons further from threshold

Inhibitory postsynaptic potential

48

What do inhibitory potentials open?

K+ or Cl- channels

49

Integration of effect of graded potentials on the postsynaptic membrane

Summation

50

Recurring activation of single synapse

Temporal summation

51

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

Spatial summation