Muscle Physiology Flashcards Preview

BIO 100 Anatomy and Physiology > Muscle Physiology > Flashcards

Flashcards in Muscle Physiology Deck (59)
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1
Q

3 general functions of muscle physiology:

A
  • movement
  • heat production
  • posture
2
Q

3 technical functions of muscle physiology:

A
  • excitability
  • contractility
  • extensibility
3
Q

Ability to be stimulated

A

Excitability

4
Q

Ability to contract or shorten

A

Contractility

5
Q

Ability to extend or stretch and return to resting length after contraction

A

Extensibility

6
Q

Muscle fiber (muscle cell)

A

Myocyte

7
Q

Myocytes have more than one _______ due to each fiber being made up of multiple cells combined into one

A

Nucleus

8
Q

Stem cells that can fuse with myocytes during strength training to make bigger muscle fibers

A

Satellite cells

9
Q

____ can become active post injury to produce more muscle fibers.

A

satellite cells

10
Q

muscle cell plasma membrane

A

sarcolemma

11
Q

muscle cell cytoplasm

A

sarcoplasm

12
Q

muscle cell smooth ER

A

sarcoplasmic reticulum

13
Q

_______ is sandwiched between sacs of the sarcoplasmic reticulum

A

Triad T-tubule

14
Q

The cytoskeleton of the muscle fiber

A

myofibrils

15
Q

Bundles of very fine filaments packed closely together that extend lengthwise along mm fiber

A

myofibrils

16
Q

contractile unit that extends between 2 z discs

A

sarcomere

17
Q

extensions of sarcolemma (the electrical wiring)

A

T tubules

18
Q

protein that binds O2 in sarcoplasm

A

Myoglobin

19
Q

regions of dense protein that separate sarcomeres

A

z discs

20
Q

The 3 kinds of protein that make up a myofibril:

A
  • contractile
  • regulatory
  • structural
21
Q

____ and _____ are contractile proteins.

A

Myosin and actin

22
Q

____ and ____ are regulatory proteins.

A
  • tropomyosin

- troponin

23
Q

several kinds of proteins that assist to stabilize the position of thick and thin myofilaments are this kind of protein

A

structural

24
Q

thin, twisted protein strands that have sites that attract myosin heads

A

actin

25
Q

thick fibers that have “heads” that cross bridge to actin active sites

A

myosin

26
Q

thin strands that block actin active sites

A

tropomyosin

27
Q

globular proteins that hold tropomyosin in place

A

troponin

28
Q

specialized nerve cells that release ACh

A

motor neuron

29
Q

folded aspect of sarcolemma where motor neuron connects

A

motor endplate

30
Q

____ binds to receptors on mm fiber

A

ACh

31
Q

junction between motor neuron and motor endplate

A

neuromuscular junction

32
Q
  1. Signal travels down motor neuron
  2. ACh released from end of motor neuron into synaptic cleft
  3. ACh binds to receptors on motor endplate
  4. Electrical impulse is transmitted to the sarcolemma
A

Excitation process of the sarcolemma

33
Q
  1. impulse travels through T tubles to sacs of ER
  2. Ca++ released into sarcoplasm and binds to troponin
  3. Tropomyosin molecules shift and expose active actin sites
  4. Myosin bridges and binds to actin to pull actin filaments toward center of sarcomere
  5. Myosin heads release and bind to next active site and pull again which results in shortening
A

Contraction

34
Q

muscle fibers contract to __% of their starting length.

A

80

35
Q
  1. SR starts pumping back Ca++ into its sacs almost immediately after releasing them
  2. Ca++ removed from troponin molecules shutting down contraction
A

Relaxation

36
Q

If no nerve pulse follows after contraction, the muscle ____.

A

relaxes

37
Q

A small amount of ____ is present inside resting muscle fibers

A

ATP

38
Q

If more ATP is needed the muscle has 3 ways to produce it:

A
  • from creatine phosphate
  • anaerobic glycolosis
  • aerobic respiration
39
Q

consists of a somatic motor neuron ans all the skeletal muscle fibers it stimulates

A

motor units

40
Q

a single somatic motor neuron comes in contact with an average of ____ skeletal muscle fibers

A

150

41
Q

containing only a few muscle fibers per neuron

A

fine motor

42
Q

large scale and powerful movements have many fibers per neuron

A

gross motor

43
Q

brief contraction of all muscle fibers in a motor unit in response to a single impulse

A

twitch contraction

44
Q

gradual, steplike increase in strength f contraction when series of twitch contractions occur about a second apart

A

Treppe

45
Q

A muscle contracts with more force after it has contracted a few times. This is called

A

Treppe

46
Q

smooth, sustained contractions, also called multiple wave summation.

Muscle doesn’t have time to relax before the next contraction starts

A

Tetanic contractions (Tetanus)

47
Q

Tension is not sustained at a constant level

A

incomplete tetanus

48
Q

continual, partial contraction in a muscle organ. A small number of fibers in a muscle contract to produce tautness. Motor units fire in relays to achieve this tone.

A

Tonic contraction

49
Q

small amount of tautness due to weak, involuntary contraction of motor units.

A

muscle tone

50
Q

4 factors that contribute to graded strength principle:

A
  • metabolic condition
  • recruitment of motor units
  • effect of muscle length on strength
  • effect of load on strength
51
Q

_____ activity is separate from muscle contraction but can positively and negatively effect contraction

A

Metabolic

52
Q

maximal strength a muscle can develop bears a direct relationship to the initial length of its fibers

A

length-tension relationship

53
Q

the heavier the load the stronger the contraction. This is…

A

effect of load on strength

54
Q

muscle shortens, tension stays the same

A

concentric contraction

55
Q

muscle lengthens, tension stays the same

A

eccentric contraction

56
Q

muscle length does not change, tension changes

A

isometric contraction

57
Q

type of muscle fiber that relies on oxygen to produce ATP, highly vascular and fatigue resistant, high concentration of myoglobin, myosin is slow acting and ATP production is able to keep up.

found in postural and endurance type muscles

A

slow oxidative fibers (red)/ slow twitch

58
Q

rely on oxygen and glycogen o produce ATP, some myoglobin and vascularity, myosin is moderately fast but more fatigue resistant than fast twitch fibers, sprint muscles

A

fast oxidative-glycolytic fibers/intermediate fibers

59
Q

relies on glycogen to produce ATP, low concentration of myoglobin and decreased vascularity, myosin is fast so rapid depletion of ATP, short duration contractions

found in muscles of fingers and eyes

A

Fast twitch (white fibers)