Muscle Tissue Flashcards Preview

Bio 103 > Muscle Tissue > Flashcards

Flashcards in Muscle Tissue Deck (84)
Loading flashcards...
1
Q

Skeletal muscle attaches by what and characteristics of it

A

tendons and aponeuroses

striated and voluntary

2
Q

Cardiac muscle epithelial characteristics

A

striated and involuntary

3
Q

Smooth muscle location and characteristics

A

hollow organs and non striated and involuntary

4
Q

Functions of muscle tissue (5)

A
  • body movement
  • body position
  • move substances within the body
  • generation of heat
  • moves nutrients
5
Q

Properties of what tissue?

-electrical excitability

A

Skeletal tissue

ability to respond to certain stimuli by making AP’s

6
Q

Properties of what tissue?

Contractility

A

Skeletal

ability to shorten and thicken generating force to do work

7
Q

Properties of what tissue?

Extensibility

A

Skeletal

stretch without damage

8
Q

Properties of what tissue?

elasticity

A

skeletal

able to return to normal shape after being stretched

9
Q

Which tissue is multi-nucleated?

A

Skeletal

10
Q

Define Fascia

A

fibrous CT that covers each organ, muscle, bone, blood vessels

11
Q

Types of Fascia

A

Superficial and Deep

12
Q

Superficial Fascia aka
contains what kind of fibers?
function

A

subcutaneous
yellow and white fibers
separates muscle from sin, lines body wall, stores fat, and protects muscle from trauma

13
Q

Deep Fascia Function

A

covers, divides, and protects muscles with similar functions

14
Q

Where are trigger points located ?
latent vs active
Usually occurs where?

A

Deep Fascia
latent-hurts when touched
active-hurts all the time
Belly of the muscle

15
Q

Cardiac Vs Skeletal

A

Cardiac has own internal activation system (intrinsic) called pacemaker cells
Smooth is not attached to skeleton

16
Q

What is Calmaudin?

A

Smooth muscles troponin

17
Q

Which systems are actin based ?

Myosin Based?

A

Actin-Cardiac and Skeletal

Myosin-Smooth

18
Q

What exists between the fascicles and their perimysium?

A

Areolar CT and adipose

19
Q

What surrounds each muscle cell ?

What cells are here?

A

Endomysium

Myosatellite cells which repair damage

20
Q

Myotubes are formed by what

Whats produced here?

A

By mypblasts fusing together which are triangular cells

Actin and Myosin are produced in cytoplasm of myotubes

21
Q

How is a myocyte/myofiber formed?

A

Myoblasts coming together by aligning with myotubes and myofibrils

22
Q

Outer covering of skeletal muscle cell is called?

A

Sarcolemma

23
Q

What are t-tubules?

Function?

A

Invagination of sarcolemma

To transmit the AP from sarcolemma to inside of muscle cell which then contracts simultaneously

24
Q

What is the Sarcoplasm?

Whats in it?

A

Muscle cell cytoplasm

Contains glycogen for energy production and hemoglobin for oxygen storage

25
Q

What are myofibrils?

A

Thick and thin filament s and contain contractile elements

26
Q

Where is the SR?

Stores what?

A

Surround each myofibril

Stores CA2+

27
Q

Where EXACTLY is Ca2+ stored?
Where is most of the Ca2+ at rest?
Where is it released?

A

Terminal cisternae of the SR
Cisternae
Released into the sarcoplasm

28
Q

Muscular atrophy vs hypertrophy

A

Atrophy- decrease in muscle mass

Hypertrophy-increase

29
Q

Thick vs thin filament names

A

Think-Myosin

Thin-Actin

30
Q

A band consists of what ?

A

primarily thick filaments-mysoin

31
Q

I bands consist of what?

A

think filaments only- Actin

32
Q

Z disc passes through where?

A

through I band (center)

33
Q

Where is the H zone located?

A

Center of A band, region of non overlap & thick filaments only

34
Q

What is mieromysin?

A

2 pairs of light chains and 2 pairs of heavy chains

35
Q

Thick lines are anchored to Z line by what ?

Adjacent filaments?

A

Titin

two proteins, more called myomysin

36
Q

Actin strands are made of?

A

2 strands of fibrous actin (F actin) which is made from 200 small globular units called G actin

37
Q

Function of Tropomyosin

A

prevents interaction of actin and myosin

38
Q

Troponin Function

A

Binds G actin to tropomyin

39
Q

How is Actin bound to Z discs?

A

Nebulin

40
Q

What are regulatory proteins and what are their functions?

A

Troponin and tropomyosin

Keep thick and them in proper alignment and give myofibril elasticity

41
Q

Function of myomesin?

A

anchors actin to adjacent filaments on M line

42
Q

What gets smaller during the sliding filament theory?

A

H and I

Z bands are moved closer together

43
Q

What is a allosteric change?

A

Calcium binding to troponin causing it to change shape

44
Q

What is a rigor complex?

How is it broken?

A

Head pulling the attached actin to and z lie toward the sarcomere
Broken by ATP connecting to myosin head

45
Q

What is a triad?

A

2 terminal cisternae and 1 t-tubule

46
Q

Duration of contraction depends on what?

A

Amount of ATP available
Duration of stimulus
Free Ca 2+ in sarcoplasm

47
Q

Where does he NMJ occur?

Neurotransmitter found here?

A

Somatic motor neuron & skeletal muscle fiber

Ach

48
Q

Where are neurotransmitters stored?

A

Synaptic vesicles

49
Q

Sources for ATP production in muscle cells (3)

A

Creatine phosphate, anaerobic & aerobic

50
Q

Where is most of ATP energy stored?

A

Phosphate bond of Creatine Phosphate

51
Q

C-P is unique to what kind of tissue?

Can also be obtained from?

A

Muscle
Milk,meat & fish
Excess ATP from relaxed muscles
synthesis of liver and kidney

52
Q

C-P and Ach amount of time for muscle contraction

A

15 second max- short distance bursts of energy

53
Q

Anaerobic Cellular Respiration
Starts where and completes where?
Max muscle activity time

A

starts in cytoplasm which is anaerobic and ends in mitochondria which is aerobic
30-40 seconds
exergonic

54
Q

Aerobic Cellular Respiration

A

ATP production in mitochondria-complete oxidation of glucose (cellular respiration), fatty acids & amino acids
exergonic

55
Q

Mitochondrial ATP is dependent on what?

A

Availability of O2 delivered to blood by muscle cells depends on rate they can use it at

56
Q

Aerobic respiration accounts for how much of ATP needed for muscular endurance?

A

90% for endurance lasting over 10 minutes

57
Q

Muscle Fatigue (6) contributors

A
Depletion of C-P
Build up of lactic acid
Insufficient O2 or glycogen
Decline of Ca2+ in sarcoplasm 
Insufficent release of Ach at NMJ
58
Q

Muscle fatigue definiton

A

More pyruvic acid used than produced by mitochondria

59
Q

Oxygen Debt caused by

A

Prolonged strenuous activity , considerable ATP production by mechanisms that don’t require oxygen

60
Q

What happens to the excess ATP in Oxygen debt?

A

Decreases the accumulation of lactic acid by converting it back to pyruvic acid

61
Q

Definition of Oxygen Debt

A

amount of oxygen the mitochondria would have used in order to produce that same amount of extra ATP

62
Q

At rest what are mitochondria doing?

A

Producing ATP and using O2 , so in muscles they are producing more ATP than needed.

63
Q

Tension depends on what?

A

depends on number of muscle fibers are contracting in unison

64
Q

Muscle tone

A

Increasing metabolic energy even at rest

65
Q

Twitch contraction

A

response of all fibers in a motor unit to a single stimulus or AP

66
Q

3 phases of twitch response

A

Latent-instant stimulation , SR is releasing the stored Ca2+
Contraction-start on contraction, until forming rigor complexes
Relaxation-max contraction to max relaxation

67
Q

Refractory Period

A

time where muscle will not respond to a second stimulus

68
Q

If a stimulus is applied to a muscle after the refractory period

A

Will respond to a second stimulus by having a second AP

69
Q

Second stimulus but has relaxed

A

Contracted state will be prolonged-tetanus

70
Q

Wave Summation

A

Second stimulus before contraction muscle has completely relaxed, so contraction is prolonged

If greater than 50 - summation of twitches

71
Q

Incomplete (Unfused) Tetanus

A

sustained muscle contraction in response to multiple stimuli 20-30 sec. permits partial relaxation between stimuli

72
Q

Complete (fused) Tetanus

A

sustained contraction in response to multiple stimuli 80-100 sec that doesn’t allow partial relaxation between stimulus

73
Q

Recruitment(multiple motor unit summation)

A

increasing number of active motor units

  • delays fatigue so contraction can be sustained
  • produces smooth muscular contraction and not jerky movements
74
Q

Muscle Tone

A

state of maintained partial contraction , essential for things like maintain posture

75
Q

Isotonic Contractions

A

tension does not change and muscles shorten and lengthen to move a weight.

76
Q

Isometric Contractions

A

muscles do not shorten or lengthen and no movement occurs, however, tension increases; maintains body posture and supports objects in a fixed position.

77
Q

What isn’t in the sarcoplasm?

A

myofibrils

78
Q

Thin & intermediate filaments are attached to ?

A

Dense bodies, help transmit from cell to cell

79
Q

Why is duration of contraction and relaxation of smooth muscle longer?

A

Longer than skeletal because of slower movement of Ca2_ ions

80
Q

The sliding of thick and thin filaments generates tension on?

A

intermediate filaments which attach to dense bodies of sarcolemma and corkscrew

81
Q

How is smooth muscle tone attained?

A

prolonged presence of calcium ions in cytosol: state of cont partial contraction.Calmodulin helps with corkscrew

82
Q

Neuromuscular diseases are from?

Myopathy?

A
  • somatic motor neurons
  • neuromuscular junction
  • muscle fibers

disease in disorder of skeletal muscle tissue

83
Q

Myasthenia gravis

A

autoimmune disorder

muscular weakness and antibodies directed against Ach receptor

84
Q

Duchenne Muscular dystrophies form of ?

A

muscular dystrophies
inherited
degeneration of individual muscle fibers