Neuromuscular communication Flashcards

1
Q

What is the order of how muscle contracts

A

electrical, chemical, mechanical

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

what is the electrical signal called

A

action potential

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

what generally causes an action potential

A

shift in membrane ion concentration

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

how is an action potential measured

A

voltage change

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

what are the 4 phases of an AP

A

resting, depolarization, repolarization/hyperpolarization, refractory period

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

what is typically the threshold mV

A

-70mV

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

why do APs have to convert to chemical signals

A

they can’t cross the synapse

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

how do AP cross the synapse

A

use neurotransmitters

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

what is the most common neurotransmitters that APs use to cross synapse

A

acetylcholine

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

what does ACh do to the synapse

A

attaches to ligand gated channels to open it

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

what do APs travel down

A

motor neuron axon

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

where do APs release ACh

A

neuromuscular junction

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

what is the result of ACh traveling down the neuromuscular junction

A

AP moves along muscle fibers

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

what is the one key determinant of muscle force

A

number of cross-bridges

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

what is a motor unit

A

alpha motor neuron +axon + all the muscle fibers it innervates

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

what is the result of an AP in an alpha motor neuron

A

muscle contraction

17
Q

can the number of motor units vary

18
Q

how are muscle fibers distributed

A

throughout, not in clusters

19
Q

what is innervation ratio

A

number of muscle fibers innervated by 1 alpha motor neuron

20
Q

what is the result on more innervation ratio

A

more force

21
Q

3 types of motor units

22
Q

what is the S type of motor unit

A

slow, non-fatiguable

23
Q

what is the FR type of motor unit

A

fast, fatigue resistant

24
Q

what is the FF type of motor unit

A

fast, fatiguable

25
what are the two characteristics that are responsible for force in a motor unit
innervation ratio and cross-sectional area
26
what is the characteristic that is responsible for fatiguability in a motor unit
fiber type
27
3 ways to measure signals in a neuron
EMG, tissue sample, force output
28
what is the purpose of an EMG
detects activity but doesn't stimulate the neuron
29
when measuring force, why doesn't the it start at zero
electromechanical delay
30
how is recruitment measured
number of active motor units
31
what happens when there is more recruitment of motor units
more force
32
is small or large motor units recruited first
small
33
how is rate coding measured
number of cross bridges
34
what does an increasing of firing APs result in
increase in force
35
what size motor unit fiber does an activity that requires less force recruit
S and maybe FR