Brainscape's Knowledge GenomeTM

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


See full index

A&P > chap 9 muscular system II > Flashcards

chap 9 muscular system II Flashcards

1
Q

how do the nerves from the brain and spinal cord extend to the skeletal muscle

A

through the axons

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

what do axons do?

A

convey electrical signals to muscle cells and initiate contraction

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

what is RMP?

A

resting membrane potential

like a charged battery ready to do work

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

what is the voltage inside the cell

A

-70 mV

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

what creates and maintains an imbalance of Na+ and K+?

A

active transport of Na+/K+ by membrane pump

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

what do CLOSED ion specific gates do?

A

prevent Na+/K+ from seeking rapid equal concentration adjustments by diffusion

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

other ion specific gates

A

ligand activated gates

voltage activated ion gates

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

how do ligand activated gates work?

A

are activated by a ligand landing on the receptor protein of the gate

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

how is ligand released?

A

due to some signal

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

how do voltage activated ion gates work?

A

opened by a rapid change in voltage within the cell

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

example of a voltage activated ion gate?>

A

potassium gate

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

what is depolarization?

A

reversal of the voltage difference

inside grows less negative

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

how does depolarization work

A

a stimulus to the cell causes some Na+ ion specific gates to open, causing Na+ to leak into the cell
this creates a voltage change

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

electrical charge for outside Na+

A

outside + positive

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

electrical charge for inside K+

A

inside - negative

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

what happens when threshold is reached?

A

if the stimulus is strong enough to cause sufficient voltage change, Na+ specific voltage gates quickly open completing rapid intense depolarizatikn

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

what happens to the electrical charge during depolarization?

A

goes from -70mV to +30mV as Na+ move in

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what happens if threshold is not reached?

A

no action potential takes place

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is action potential?

A

the rapid changing of membrane potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what is the all or none principle

A

if the ligand-gated Na+ entry is above threshold, then no more neurotransmitter ligand is necessary to open the rest of the voltage gated channels and complete the action potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

repolarization

A

put membrane back to RMP

22
Q

steps of repolarization

A

with the abundance of Na+, charge is +30. this trigggers the K+ specific voltage gated channels to open
K+ then rushes out, using laws of diffusion
intracellular environment returns to -70mV, returning to RMP

23
Q

homeostasis

A

an ion imbalance across the membrane must exist or ions will not move or move as rapidly when gates are opened

24
Q

what help maintain the -70mV during RMP

A

Na+/K+ pump

25
Q

propagation

A

spreading of a signal throughout the cell

26
Q

result of propagation

A

muscle cells contract, nerve cells send impulses

27
Q

what happens if they is repeat stimulation?

A

action potentials increase the strength of the cell response which results in an increase in strength or duration of contraction in muscle cells

28
Q

synapse

A

neuromuscular junction

transfer site of motor neuron action potential to skeletal muscle cell action potential

29
Q

what stimulates each muscle fiber

A

the terminal branch of axon

30
Q

structures of neuromuscular junction

A

presynaptic terminal
synaptic cleft
postsynaptic membrane

31
Q

presynaptic terminal

A

the end

sends the message

32
Q

postsynaptic membrane

A

“motor end plate”

skeletal muscle cells

33
Q

steps of neuromuscular junction

A
  1. action potential travels down moto neuron membrane to the presynaptic terminal
  2. Ca2 specific voltage gates open and Ca2+ diffuses inwards
  3. triggers neurotransmitter vesicle release by exocytosis into the synapse
  4. result of action potential across the muscle fiber
34
Q

acetylcholine

A

ACh

is the excitatory NT of the NMJ

35
Q

what happens after the exocytosis into the synapse

A

ACh ligand binds to ACh receptors on muscle fiber post synaptic membrane activating ligand gate Na+ channels
depolarization of the postsynaptic membrane generates action potential

36
Q

what happens to ACh?

A

ACh is quickly broken down

ACh-> acetic acid + choline

37
Q

purpose of choline

A

to be reuptaked to more more ACh

38
Q

acetic acid

A

bad

formed from a variety of metabolic responses

39
Q

enzyme responsible for ACh breakdown

A

acetylcholineesterase AChE

40
Q

result of action potential across the muscle fiber

A

excitation-contraction coupling

41
Q

steps after action potential created

excitation-contraction coupling

A

1) T-tubule invagination takes the sarcolemma depolarization into the S
2) Ca2+ is released internally (200x normal concentration_
3) Ca2+ binds to the regulatory troponin and exposes myosin binding site
4) myosin head engages and power stroke ensues
5) ATP molecule energy uses to unhook myosin and recock head

42
Q

what do organophosphate pesticides and some nerve gases do?

A

block the action of AChE

result in transient spastic paralysis

43
Q

spastic transient paralysis

A

fibers constantly stimulated, unable to relax and eventually fatigue
death through respiratory failure
importance of protecting populations and workers from sprays

44
Q

why would solders be given syringes of atropine sulfate which blocks postynaptic membrane ACh receptor sites?

A

??

45
Q

what happens to blocked postynaptic membrane ACh receptors

A

limits membrane depolarization
flaccid paralysis results
myasthenia gravis

46
Q

flaccid paralysis

A

muscles unable to respond

47
Q

myasthenia gravis

A

your antibodies from response to viral infection damage ACh receptors
muscle weakness
most survive but end up in coma and require ventilation

48
Q

treatment for myasthenia gravis

A

neostigmine, which interferes with AChE action, tries to keep whatever ACh is already there

49
Q

recovery stroke

A

ATP dependent release of myosin head and recocking

50
Q

what is muscle contraction?

A

produced by many quick repeats of the cycle in each fiber that has been stimulated by the neuron

51
Q

what happens when no more stimulus is present?

A

relaxation of muscle tissue

Ca2+ are rapidly moved back into the SR by active transport (ATP needed)

52
Q

rigor mortis

A

stiffness that covers body several hours after death. loss of intracellular containment of the Ca2+ and lack of ATP causes constant increasing contractions (rigor) in the hours after death.
after 24 hours the muscle cell proteins will deteriorate and begin to relax

A&P (18 decks)

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