Chapter 10 Flashcards

1
Q

skeletal muscle

A

muscle that covers bone. striated and voluntary

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

cardiac muscle

A

heart, striated, involuntary

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

smooth muscle

A

hollow visceral organs, non-striated and involuntary

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

7 skeletal functions

A

movement, posture, supports soft tissues, stabilizing joints, guards opening, generate heat, stores nutrients

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

muscle fibers

A

muscle cells thousands of which make up a muscle

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

epimysium

A

dense layer of collagen that surrounds the entire muscle; connects to deep fascia

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

perimysium

A

divides muscles into compartments; within each is a fascicle (a bundle of muscle fibers)

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

endomysium

A

surrounds individual muscle fibers; flexible, elastic connective tissue contains: capillaries, nerve fibers and myosatellite cells

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

These three layers fuse at the end of a muscle to create a tendon or aponeurosis that attaches to a bone

A

tendons, origin, insertion

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

tendons

A

fibrous connective tissue that merges with the periosteum of bones, connects muscles to bones or other muscles

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

origin

A

immobile bone muscle attachment

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

insertion

A

moveable bone muscle attachment, it always moves toward the origin

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

Muscle cells are extremely ____ and ____?

A

large

multinucleate

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

Myoblasts

A

primitive muscle cells that fuse during development contributing to the large size and multinuclea features

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

Myosatellite

A

myoblast cells that have NOT fused and are found in adult muscle tissue. they are stem cells that aid in muscle repair

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

Sarcolemma

A

muscle cell membrane

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

Sarcoplasm

A

the cytoplasm of a muscle cell

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

T-Tubules

(transverse tubules

A

extensions of the sarcolemma that run deep into the muscle cell so that an action potential can effectively depolarize a muscle cell quickly/completly

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

Myofibrils

A

cylindrical structures within a muscle fiber that contain proteins responsible for contraction. 100-1000 in ea. cell, they run the length of the cell and attach at the ends to a tendon

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

myofillaments

A

bundles of protein filaments within myofibrils, they contain; actin, myosin and titin

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

Actin

A

a THIN protein filament

contains myosin binding sites to aid in contraction; also contains troponin and tropomyosin

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

Myosin

A

a THICK protein filament. contains a myosin head which interacts with the thin filament

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

High amounts of ____ and ____ are found scattered among the myofibrils for high ____ production

A

glycongen, mitochondria, energy

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

Sarcoplasmic reticulum

A

a modified form of the ER found in muscle cells

The SR is a reservoir for calcium ions that can be released into sarcoplasm to stimulate contraction

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

Terminal Cisternae

A

expanded chambers that form when sarcoplasmic reticulum fuse

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

Triad

A

a combo of a pair of terminal cistern and a t-tubule

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

Sarcomeres***

know figure 10-4 and 10-5!

A

this is the FUNCTIONAL unit of the muscle, a chain of smaller contractile units within myofibril

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

A bands

A

the DARK bands found at the center of ea. sarcomere

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

M line

A

found in the MIDDLE of the A band; connect nerighboring thick filaments

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

H band

A

a lighter region on either side of the M line; contains thick filaments but no thin filaments

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

Zone of overlap (fig. 10-5)

A

dark region where thin filaments and thick filaments overlap; 3 thick filaments surround ea. thin filament and 6 thin filaments surround ea. thick filament

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

I bands

A

light bands containing thin filaments only and extend from the A band of one sarcomere to the A band of the next

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

Z line

A

protein discs that are the end lines of a sarcomere and interconnect thin filaments of adjacent sarcomeres; actin (thin) attach to the Z line on ea. end of the sarcomere; Z lines give striates muscle its stripes

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

Titin

A

elastic protein strands that anchor myosin to the Z line; inhibits muscles from stretching too far (stretch and recoil)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Troponin and Tropomyosin

A

inhibitory proteins that prevent actin from sliding with myosin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

neuromuscular junction

A

where the motor neuron terminates on the muscle fiber; ea. muscle fiber has its own neruromuscular junction that controls it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

axon terminal

A

enlarged tip of the motor neuron containing sacs of the neurotransmitter, acetylcholine

38
Q

sarcolemma

A

muscle fiber cell membrane. contains recptor sites for acetylcholine (neurotransmitter) and acetycholinesterase (inacivator)

39
Q

T tubules

A

inward folds of the sarcolemma which carry the action potential to the interior of the muscle cell

40
Q

synapse

A

the small space between the axon terminal and the sarcolemma

41
Q

During muscle contraction…. 6 steps:

A
  1. sarcomeres shorten, 2. muscle fibers contract (shorten), 3. H and I bands get smaller, 4. zones of overlap get bigger, 5. Z lines move closer together, 6. A bands remain the same
42
Q

Arrival of the action potential, step 1

A

a nerve impulse arrives at axon terminal, ACH is released into synapse

43
Q

…action potential, step 2

A

sarcolemma receives ACH into its receptor sites and causes Na+ to rush into cell

44
Q

…action potential, step 3

A

sarcolemma is depolarized, T-tubules bring action potential to the interior of muscle cell

45
Q

…action potential, step 4

A

ACHE inactivates ACH

46
Q

…action potential, step 5

A

calcium ions are released from cisternae of sarcoplasmic reticulum into the sarcoplasm in response to depolarization; the Ca+ binds to the troponin-tropomyosin complex to free up the myosin receptor sites on the actin filament

47
Q

…action potential, step 6

A

myosin splits ATP to release energy, myosin heads attach to actions myosin binding site and pulls actin filaments towards the center of the sarcomere

48
Q

…action potential, step 7

A

all the sarcomeres shorten, muscle fiber contracts

49
Q

Resting sarcomere

A

myosin heads are charged, pointing away from the M line

50
Q

Contracted sarcomere

A

ATP splits and continues to ‘re-cock’ the myosin heads as long as there is sufficient calcium

51
Q

How long a contraction lasts depends on what three things?

A
  1. period of stimulation at the neuromuscular junction 2. presence of calcium in the sarcoplasm 3. amount of ATP available
52
Q

muscle tone

A

always on enables fast reaction, muscles are always in a slight state of contraction except in certain stages of sleep

53
Q

Functions of muscle tone

A

maintains posture, helps prevent sudden changes in body movement, allows for shock absorption

54
Q

Good muscle tone improves

A

coordination, because when muscles are slightly contracted they can react more quickly and with greater exertion

55
Q

good muscle tone increases a ____ ___which can aid in ____ and ___ ____

A

resting metabolism, exercise and weight loss

56
Q

Alternate muscle fibers ____ so the muscle does not

A

contract, tire out

57
Q

Isotonic contraction

A

tension rises and a muscles length changes bringing about movement

58
Q

concentric contraction

A

muscle tension exceeds load and muscle shortens

59
Q

eccentric contraction

A

tension is less than the load, the muscle elongates due to the contraction of another cuscle or pull of gravity

60
Q

isometric contraction

A

the muscle does not change load because the tension produced never exceeds the load; contraction without movement

61
Q

Returning a muscle to resting length

A

a muscle can actively shorten but they cannot actively lengthen

62
Q

elastic force

A

recoil to original length

63
Q

opposing muscle contraction

A

the contraction of opposing muscles can return a muscle to its resting length

64
Q

Gravity

A

muscles relax and gravity pulls a limb down and stretches the muscle to resting length

65
Q

ATP

A

there is not enough stored in muscles and it is depleted quickly so it has to be generated quickly

66
Q

creatine phosphate

A

ATP that is not being used by a resting muscle is transferred to creatine to be stored for later

67
Q

Creatine Kinase

A

when high amounts are found in the blood concentration it indicates sever muscle damage

68
Q

Glycogen

A

most abundant energy source, broken down to glucose then broken down to pyruvate to form ATP though the krebs cycle; glcogen is important for sustained contraction

69
Q

Anaerobic metabolism

A

provides a small amount of ATP within a muscle cell
provides 95% of ATP production in a resting cell by the breakdown of fatty acids; when a cell becomes active, it breaks down pyruvate allowing for energy production

70
Q

Anaerobic metab/glycolysis step 1.

A
  1. glycolysis occurs in the sarcoplasm, glucose is broken down into two pyruvate molecules without oxygen, this makes glycolysis anaerobic
    glycolysis makes small amounts of ATP (2 molecules) which can be used by the cell when energy demands are at a maximum and O2 is limited
71
Q

Aerobic metab. step 2 and 3

A
  1. mitochondria absorbs pyruvate

3. a CO2 molecule is removed from ea. pyruvate molecule in the mitochondria

72
Q

Aerobic metab. step 4

A

the remainder of pyruvate enters the citric acid/krebs cycle which breaks down the pyruvate into CO2 and H+

73
Q

Aerobic metab. step 5 and 6

A
  1. H+ are transferred to oxygen atoms to form water

6. all of these steps ultimately support the conversion of ADP to ATP

74
Q

Every molecule of pyruvate fed into the citric acid cycle produces ____

A

17 ATP molecules

75
Q

Muscle fatigue

A

when the muscle can no longer perform

76
Q

normal muscle function requires (1-4)

A
  1. energy reserves, 2. circulatory supply, 3. normal blood oxygen levels, 2. normal blood PH
77
Q

Muscle can fatigue due to (1-4)

A
  1. depletion of energy reserves, 2. damage to sarcolemma or SR, 3. decrease in PH which affects proper calcium binding, 4. decreased desire to continue activity due to pain and low blood PH
78
Q

Lactic acid build up

A

at peak levels of muscle activity, pyruvate builds up in the cell faster than mitochondria can utilize it; it converts at this point to lactic acid which releases hydrogen molecules and lowers the ph of the sarcoplasm=fatigue

79
Q

Lactic acid removal and recycling

A

muscles can continue to contract in the absence of oxygen due to glycolysis but at the expense of producing lactic acid and lowering tissue fluid ph

80
Q

Lactic acid removal/recycling, 3 facts

A
  1. during recovery oxygen levels become abundant again
  2. lactic acid can be converted back to pyruvate in the presence of oxygen
  3. pyruvate is then used to boost glycogen reserves or to generate more ATP for normal cell function
81
Q

Oxygen debt

A

the amount of oxygen needed to restore pre-exertion conditions…
during exertion oxygen has been depleted, recovering oxygen demands are elevated, we owe the body oxygen for restoring ATP, CP and glycogen to their former concentrations

82
Q

Recovery oxygen uptake

A

increase heart rate respiratory and heart rate remain high for a period of time after exercise to repay O2 debt

83
Q

Types of skeletal muscle fibers

A

fast, slow and intermediate

84
Q

Fast Fibers

A
  • most common
  • lrg in diameter
  • densely packed myofibrils
  • lrg glycogen reserves
  • few mitochondria
  • produce powerful contractions because of high numbers of myofibrils
  • fatigue quickly cuz they use lots of ATP and there is not enough mitochondria to make more
  • prolonged activity supported by anaerobic metabolism
85
Q

Slow Fibers

A
  • half the diameter of fast fibers
  • more resistant to fatigue
  • numerous mitochondria
  • higher oxygen due to more capillaries
  • contain myoglobin (red pigment carries O2, makes it dark red)
86
Q

Intermediate Fibers

A
  • appearance is closer to fast fibers (little myoglobin and appear pale)
  • function is between fast and slow fibers
87
Q

white muscles

A

dominated by fast fibers, pale, used for power

88
Q

red muscles

A

dominated by slow fibers, blood vessels and myoglobin, give it a red color

89
Q

Hypertrophy

A

muscle fibers increase in diameter due to increased number of myofibrils from repeated/intense stimulation

90
Q

atrophy

A

reduction in muscle size (loses tone and mass) due to lack of stimulation, reversible at first but if fibers die they cannot be replaced