LEC EXAM #3 CHP 9 Flashcards

1
Q

6 functions of skeletal muscle:

A
  1. skeletal movement
  2. store nutrient reserves
  3. support soft tissues
  4. guard openings
  5. body temperature
  6. body position
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Myoglobin is specific to:

A

Skeletal and cardiac muscle tissues

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

Myoglobin binds:

A

Oxygen

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

What is a power stroke?

A

Movement of myosin cross bridges pushes actin towards center of sarcomere

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

What does the end of a power stroke consist of?

A

Myosin releases bound actin and grabs another actin molecule

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

Skeletal muscle stores:

A

Glycogen

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

Striations have:

A

Contractile fibers

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

When muscle tissues are damaged they release:

A

Myoglobin into blood and lactate dehydrogenase

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

Dark line:

Light line:

A

Myosin

Actin

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

Myoglobin has a higher affinity for:

A

O2

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

Skeletal muscle structure:

A

Repeating circular bundles

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

What is tennis elbow?

A

Makes sheaths flat instead of round

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

What is stored at the sarcoplasmic reticulum?

A

Calcium

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

Z line connects/anchors:

A

Actin (always thin)

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

Space where there is ONLY actin:

A

I band

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

Space where actin and myosin overlap:

A

A band

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

M line anchors:

A

Myosin (always thick)

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

Space where there is ONLY myosin:

A

H band

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

Sheath like protein that covers binding site:

A

Tropomyosin

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

Beaded complex where calcium binds:

A

Troponin

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

ATPase is where:

A

ATP binds to get myosin head activated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the steps of contraction?

A
  1. AP in t-tubule alters DHP receptor
  2. DHP receptor causes calcium to bind to troponin
  3. Moves tropomyosin out of the way for myosin to bind to actin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Why do we need calcium?

A

To move tropomyosin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Neuromuscular junction:

A

Regulates force

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Axon contains:

A

Na V.G.C.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

The nerve synapses with the skeletal muscle at the:

A

Motor end plate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Acetylcholesterase:

A

An enzyme that breaks down acetyl–coa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

The holes of the t-tubule take it deep into the:

A

Skeletal muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Relaxation steps:

A

ATP pulls apart actin and myosin cross bridge
ATP splits into ADP and phosphate
Activates head for power stroke
ADP and phosphate leave

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What stops skeletal muscle contraction?

A

Nerve by nerve impulse shutting off -> no more acetyl-coa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What regulates skeletal muscle?

A

Somatic nervous system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Relaxation begins in the:

A

Brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Relaxation requires:

Contraction requires:

A

ATP

Calcium and ATP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Rigor mortis:

A

Stiffness of muscles after death for 72 hours, caused by lack of ATP

35
Q

TEA:

A
  • Blocks potassium voltage gated channels
  • K+ cannot repolarize via K+ v.g.c.
  • long drawn out repolarzation-> hyper-excitable (above 55)
36
Q

Curare:

A
  • Blocks nicotinic cholinergic receptors
  • no nerve->nerve conduction
  • no nerve-> skeletal muscle conduction
37
Q

Esterine/physostigmine:

A
  • blocks Acetylcholesterase (AchE)
  • Ach stays in synapse
  • continued contraction
38
Q

Organophosphates (never toxins):

A
  • blocks AchE

- causes continuous contraction

39
Q

Myasthenia gravis:

A
  • autoimmune disease
  • antibodies attack nicotinic cholinergic receptors
  • no AP/ no skeletal muscle contraction
  • use eserine to increase Ach in the synapse
40
Q

What allows action potentials to go deep into where contractile fibers are? (nerve-> skeletal muscle)

A

T-tubules

41
Q

What floods into the area where the contractile fibers are, causing excitement of skeletal muscle?

A

Calcium

42
Q

Once calcium floods the area where the contractile fibers are, where the actin and myosin are, what does calcium bind to?

A

Troponin

43
Q

Calcium then moves:

A

Tropomyosin away from the actin

44
Q

What ion or molecule do we have to have to move tropomyosin?

A

Calcium

45
Q

Myosin is now bound to actin, what causes the power stroke/contraction?

A
  • Phosphate leaves
  • get power stroke
  • then ADP leaves
  • stuck here until ATP binds
46
Q

ATP releases:

A

crossbridge

47
Q

ATP will bind if:

A

Calcium is present

48
Q

REQUIRED for contraction/power stroke:

A

ATP and calcium

49
Q

What ion causes the vesicle to dump into the synapse?

A

Calcium

50
Q

Curare does not effect:

A

nerve -> heart

nerve -> digestive tract

51
Q

If curare is stuck here, what cannot bind?

A

Ach

52
Q

Threshold stimulus:

A

Strength of stimulus required to cause a twitch

53
Q

Latent period:

A

Delay between stimulus and contraction

54
Q

Twitch:

A

Single, brief contraction of a muscle fiber after a single threshold stimulus

55
Q

Relaxation is caused by:

A

Transport of calcium back into the sarcoplasmic reticulum

56
Q

What is the “all or none” principle?

A

At threshold, a fiber will contract its maximum extent

57
Q

Tension of a single muscle fiber depends on:

A
  • fiber’s resting length at time of stimulation
  • frequency of stimulation
  • number of pivoting cross bridges
58
Q

Skeletal muscles are capable of:

A

graded responses

59
Q

The force of muscle contraction can increase by:

A

Summation or recruitment

60
Q

Refractory period:

A

time between initial and subsequent stimuli that is required for sarcolemma to repolarize

61
Q

Summation:

A

Greater force generated from more frequent stimuli

62
Q

Tetanic contraction:

A
  • Continuous contraction without relaxation between stimuli

- all motor units of muscle are activated

63
Q

Fatigue:

A

Loss of response due to lack of ATP

64
Q

Motor unit:

A

Motor neuron + all the fibers it controls

65
Q

Motor unit rule:

A

All muscle cells in a motor unit respond maximally, or they don’t respond at all

66
Q

Each motor neuron on average controls:

A

150 fibers

67
Q

Recruitment:

A

increasing the number of motor units activated/responding

68
Q

Strength increases as…

A

the number of motor units increases

69
Q

2 types of tension production:

A
  • sustained tension

- muscle tone

70
Q

Sustained tension:

A
  • less than maximum tension
  • allows motor units to rest in rotation
  • uses a lot of ATP
71
Q

Muscle tone:

A

-the normal tension and firmness of a muscle at rest

72
Q

Increasing muscle tone increases:

A

metabolic energy used even at rest

73
Q

We use sustained tension to:

A

Actively maintain body position without motion (isometric contraction)

74
Q

CrP (creatine phosphate):

A

stored in skeletal muscle and used to make ATP for skeletal muscle contraction

75
Q

When muscle can no longer perform a required activity, they are:

A

Fatigued

76
Q

4 results of muscle fatigue:

A
  • depletion of ATP
  • damage to sarcolemma and sarcoplasmic reticulum
  • low pH
  • muscle exhaustion and pain
77
Q

The time required after exertion for muscles to return to pre-exercise condition:

A

Recovery period

78
Q

In recovery period, you have to deal with: (3)

A
  • depletion of metabolic reserves by making more glycogen and ATP via aerobic metabolism-> breath heavy
  • repair sarcolemma and sarcoplasmic reticulum
  • recover from low pH by processing lactic acid via cori cycle
79
Q

How does the cori cycle play a role in recovery period? (3)

A
  • removal and recycling of lactic acid by the liver
  • liver converts lactic acid to pyruvic acid
  • glucose is released to recharge muscle glycogen reserves
80
Q

Muscle hypertrophy:

A

muscle growth from heavy training

81
Q

Muscle atrophy:

effects:

A

lack of muscle activity

-reduces muscle size, tone, and power

82
Q

3 effects of muscle hypertrophy:

A
  • increases diameter of muscle fibers
  • increases number of myofibrils
  • increases mitochondria, glycogen reserves
83
Q

Muscle fibers break down into:

A

Proteins