The action potential Flashcards Preview

Undeleted > The action potential > Flashcards

Flashcards in The action potential Deck (28):
1

what are muscle spindles

stretch receptors of skeletal muscle

2

what happens when stretch the mechanoreceptors

opening of Na channels causing receptor potential

3

what type of potential are receptor potentials

graded - good for strength coding

4

what happens to receptor potentials over space

decremental - decrease

5

what does action potential begin

spike initiation zone

6

how is info coded in action potential

frequency and pattern of AP

7

5 phases of an AP

1. resting
2. rising
3. overshoot
4. falling (repolarizing)
5. hyperpolarization

8

what is AP threshold

minimum voltage that must be reached to initiate - 55mV

9

what happens with more depolarization

more frequent AP

10

what limits AP frequency

refractory period (absolute or relative)

11

what opens with AP

Na and K channels

12

which channel opens faster

Na, and K sustains over depolarization

13

what are 3 states of Na channel

1. resting
2. activated
3. inactivated

14

what reverses inactivation of Na channel

regaining -70

15

what happens during threshold phase

inward Na> outward L

16

what happens during rising phase

rapid opening of Na channels

17

what happen in overshoot

Na inactivation and delayed opening of VG K channels

18

what happens in falling phase

Na inactivation and K

19

what happens in hyperpolarization

residuale VG K and IL

20

what happens in absolute refractory period

Na channel inactivation prevents AP generation

21

what is direction of Na channel propagation of channel

orthodromic

22

what determines speed of conduction

length of membrane

23

what happens with larger diameter axon

less axial resisitance- faster conduction

24

what forms myelin in PNS and CNS

PNS - schwann cells
CNS - oligodendricites

25

what are interuptions in myelin

nodes of ranvier

26

what is conduction that jumps along nodes

saltatoy conduction

27

what are diseases that demylenate PNS and CNS

PNS - guillain-barre
CNS- MS

28

how does local anasthetic work

blocks Na channels of pain fibers so can't give signal

Decks in Undeleted Class (589):