Skeletal Muscle And Nervous Tissue Flashcards

1
Q

Contraction of muscle occurs when thin _____ microfilaments and thick _____ filaments slide past one another

A

Actin; myosin

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2
Q

Actin and myosin filaments are organized into structures called ______

A

Myofibrils

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3
Q

What are the 3 types of muscle tissue?

A

Skeletal muscle

Cardiac muscle

Smooth muscle

[differences in distribution, structure, and function]

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4
Q

_________ muscle is striated, voluntary, utilized in movement and posture, and makes up 40% of the body mass

A

Skeletal

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5
Q

_________ muscle is non-striated, involuntary, visceral organ tone and movement function, found in walls of hollow viscera, and blood vessels (vasodilation and vasoconstriction)

A

Smooth

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6
Q

_______ muscle is striated, involuntary, and pumps blood through the cardiovascular system

A

Cardiac

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7
Q

Is skeletal muscle striated/unstriated? Voluntary/involuntary?

A

Striated

Voluntary

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8
Q

Is cardiac muscle striated/unstriated? Voluntary/involuntary?

A

Striated

Involuntary

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9
Q

Is smooth muscle striated/unstriated? Voluntary/involuntary?

A

Non-striated

Involuntary

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10
Q

Skeletal muscle cells are called _______

A

Myocytes

[may also be called myofibers or muscle fibers]

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11
Q

Groups of myofibers form _______

A

Fascicles

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12
Q

3 layers of CT organize myofibers into an organ (a skeletal muscle). What are they?

A

Endomysium
Perimysium
Epimysium

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13
Q

__________ are separated by CT called endomysium

__________ are separated by CT called perimysium

____________ is the CT layer that surrounds the entire muscle

A

Myofibers

Fascicles

Epimysium

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14
Q

T/F: skeletal muscle cells are mononucleated cylinders commonly referred to as myofibers

A

False - myofibers are MULTINUCLEATED

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15
Q

Skeletal muscle cells are multinucleated; where are these nuclei located and why?

A

Nuclei are located in the periphery of the cell because the cytoplasm is primarily occupied by myofibrils

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16
Q

What is the basic structural unit of the myofibril?

A

Sarcomere

Each cell has thousands of them

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17
Q

The ______ is the transparent sheath that envelopes the fibers of skeletal muscles

A

Sarcolemma

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18
Q

What organelle associated with myofibers functions in calcium storage?

A

Sarcoplasmic reticulum

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19
Q

______ _______ are invaginations of the sarcolemma

A

Transverse tubules (t-tubules)

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20
Q

__________ ________ = dilated ends of sarcoplasmic reticulum that release calcium which triggers muscle contraction

A

Terminal cisternae

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21
Q

A single sarcomere extends from one _____-line to another

A

Z

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22
Q

T/F: When a muscle cell contracts, EVERY sarcomere shortens

A

True

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23
Q

What are the 5 components of a sarcomere?

A
Z-line
I-band
M-line
H-zone
A-band
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24
Q

_______ = the part of the sarcomere that serves as the anchor site for thin actin filaments

A

Z-line

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25
Q

_________ = the part of the sarcomere that contains only actin filaments

A

I-band

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26
Q

________ = the part of the sarcomere that serves as the anchor site for thick myosin filaments

A

M-line

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27
Q

______ = the part of the sarcomere that contains only thick myosin filaments

A

H-zone

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28
Q

______ = the part of the sarcomere that contains overlap of thick and thin filaments plus the H-zone

A

A-band

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29
Q

Describe the sliding filament mechanism of a typical sarcomere

A

When a muscle cell contracts, the thin filaments slide past the thick filaments toward the center, bringing the z-lines closer together

Every myofibril in a muscle cell shortens at the same time, thus the entire muscle cell contracts

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30
Q

T/F: the sliding filament mechanism of sarcomeres involves changes in length of the thin and thick filaments, leading to shortening of the sarcomere with contraction

A

False! The thin and thick filaments do not change in length, instead the degree of overlap does!

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31
Q

What is required for actin binding and release during muscle contraction?

A

ATP hydrolysis

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32
Q

__________ is a regulatory protein associated with skeletal muscle contraction that runs in the groove formed by F-actin strands and binds to the troponin complex

A

Tropomyosin

33
Q

What are the 3 proteins that make up the troponin complex?

A

Troponin T
Troponin I
Troponin C

34
Q

What component of troponin binds the complex to tropomyosin?

A

Troponin T

35
Q

What component of troponin inhibits the binding of myosin to actin?

A

Troponin I

36
Q

What component of troponin binds calcium?

A

Troponin C

37
Q

Troponin C is only found in ______ muscle

A

Striated

38
Q

Muscle fibers are categorized by what 2 factors?

A

Type of contraction generated (differ in power, speed, duration)

ATP supply

39
Q

What type of skeletal muscle fibers are also known as slow oxidative fibers?

A

Type I fibers

40
Q

What type of skeletal muscle fibers are also known as fast oxidative fibers?

A

Type Ia fibers

41
Q

What type of skeletal muscle fibers are also known as fast glycolytic fibers?

A

Type IIb

42
Q

What are the 3 types of skeletal muscle fiber types?

A

Type I fibers (slow oxidative)

Type Ia fibers (fast oxidative)

Type IIb fibers (fast glycolytic)

43
Q

What type of skeletal muscle fibers is the largest and most prevalent?

A

Type IIb fibers (fast glycolytic)

44
Q

Which type of skeletal muscle fiber contains slow ATPase, is red due to increased myoglobin, contractions are slow and not powerful, and can contract for long periods of time without fatigue?

A

Type I fibers (slow oxidative)

45
Q

Which type of muscle fibers have fast ATPases which provide power and speed, primarily anaerobic, contract for short bursts, and lack myoglobin?

A

Type IIb fibers (Fast glycolytic)

46
Q

What type of skeletal muscle fibers are least numerous, fast ATPases, primarily aerobic respiration with low O2 delivery rate, and contain myoglobin?

A

Type Ia fibers (fast oxidative)

[note that they contain less myoglobin than slow oxidative fibers]

47
Q

What are the 2 basic cell types associated with nervous tissue?

A

Neurons

Neuroglia

48
Q

Neurons are specialized for conduction of electrical impulses. What are the 2 major parts to a neuron?

A

Cell body (aka soma or perikaryon)

Cell processes (dendrites and axons)

49
Q

Neuron clusters in the PNS are referred to as ________

A

Ganglia

50
Q

Neuron clusters in the CNS are referred to as ______

A

Nuclei

[but sometimes ganglia]

51
Q

_______ are neuron support cells

A

Neuroglia

52
Q

Which are larger: neurons or neuroglia?

A

Neurons are much larger

53
Q

________substance is abundant in the RER, reflecting the need to make lots of neurotransmitters and protein to maintain the large size of the neuron

A

Nissl

54
Q

What part of the neuron processes the electrical information?

A

Cell body

55
Q

What part of the neuron carries electrical signals toward the nerve cell body?

A

Dendrites

56
Q

What part of the neuron carries electrical signals away from the nerve cell body?

A

Axon

57
Q

What part of the neuron is where the electrical signals are transferred from the axon terminal of the nerve to an effector cell?

A

Synapse

58
Q

What are the 3 structural classes of neurons?

A

Multipolar - many dendrites, one axon

Bipolar - one dendrite, one axon

Unipolar - one cell process from which branches a single axon and single dendrite

59
Q

What cell type forms myelin in the PNS?

A

Schwann cells

60
Q

What 2 cell types surround neurons in the PNS?

A

Satellite cells (“orbit” body of neuron)

Schwann cells (form myelin)

61
Q

T/F: axons in the CNS and PNS can be myelinated or unmyelinated

A

True

62
Q

What cell type forms myelin in the CNS?

A

Oligodendrocyte

63
Q

T/F: even unmyelinated axons are physically associated with Schwann cells and oligodendrocytes

A

True

64
Q

What is the purpose of nodes between myelin sheaths?

A

Transmission signal jumps from node to node, increasing the speed of conduction

65
Q

The organization of CT surrounding peripheral nerves is similar to that of skeletal muscle.

What is the term for the CT between axons?

A

Endoneurium

66
Q

The organization of CT surrounding peripheral nerves is similar to that of skeletal muscle.

What is the term for the CT surrounding clusters of axons forming fascicles?

A

Perineurium

67
Q

The organization of CT surrounding peripheral nerves is similar to that of skeletal muscle.

What is the term for the CT surrounding several nerve fascicles?

A

Epineurium

68
Q

What are the 4 parts of a chemical synapse?

A

Presynaptic knob (axon terminal)

Synaptic cleft

Presynaptic membrane

Postsynaptic membrane

69
Q

_______ _____ in the presynaptic knob contain a neurotransmitter that’s released into the synaptic cleft by exocytosis

A

Synaptic vesicles

70
Q

The neurotransmitter released from synaptic vesicles in the presynaptic knob bind to receptors on the postsynaptic membrane, stimulating the postsynaptic cell.

What are some examples of neurotransmitters?

A

Acetylcholine

Noradrenaline

71
Q

T/F: every skeletal muscle cell, cardiac muscle cell, and smooth muscle cell receive an axon terminal

A

False: every skeletal muscle cell receives an axon terminal but not all cardiac or smooth muscle cells are directly innervated

72
Q

What structure between axon and muscle cell allows entire muscle to contract vs. just one muscle cell?

A

Motor end plate

73
Q

What structures associated with muscle cells monitor changes in length, rate of change, and tension of muscle?

A

Muscle spindle receptors

74
Q

_________ fibers = specialized fibers inside the muscle spindle

A

Intrafusal

75
Q

What are the 2 types of intrafusal fibers?

A

Nuclear bag fibers

Nuclear chain fibers

76
Q

What type of intrafusal fibers are wrapped at their ends by type II nerve fibers and detect static muscle length?

A

Nuclear chain fibers

77
Q

What type of intrafusal fibers are wrapped at the center by type Ia nerve fibers and detect change in length and degree of tension?

A

Nuclear bag fibers

78
Q

_________ fibers = muscle fibers outside the muscle spindle

A

Extrafusal

79
Q

What is the major type of extrafusal muscle fibers?

A

Alpha motor fibers