Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Anatomy and Physiology I > Lesson 20 > Flashcards

Lesson 20 Flashcards

1
Q

muscle means literally…

A

little mouse

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

muscular system refers only to…

A

skeletal muscle

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

myology

A

the study of the muscular system

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

excitability (responsiveness)

A

respond to chemical signals, stetch, and electrical changes across the plasma membrane

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

conductivity

A

local electrical excitation sets off a wave of excitation that travels along the muscle fiber

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

contractility

A

shorten when stimulated

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

extensibility

A

capable of being stretched between contractions

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

elasticity

A

returns to its original rest length after being stretch

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

striations

A

alternating light and dark transverse bands; results from arrangement of internal contractile proteins

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

voluntary

A

usually subject to conscious control

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

skeletal muscle cells are also called _____ _____ or _____

A

muscle fibers, myofibers

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

six functions of skeletal muscle

A
  1. produce skeletal movement
  2. maintain posture and body position
  3. support soft tissues
  4. guard entrances and exits
  5. maintain body temperature
  6. store nutrients
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

endomysium

A

fibrous connective tissues that surrounds each muscle fiber

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

perimysium

A

bundles muscle fibers into fascicles

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

epimysium

A

surrounds entire muscle

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

collagen (4)

A
  • stretches slightly under tension and recoils when released
  • resists excessive stretching to protect muscle from injury
  • returns muscle to original length
  • contributes power output and muscle efficiency
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

fascicles

A

bundles of muscle fibers wrapped together

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

fascia

A

sheet of connective tissue between muscles or muscle groups

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

what does the endomysium allow room for?

A

capillaries and nerve fibers

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

what type of cells does the endomysium contain?

A

myosatellite cells (stem cells) that repair damage to muscle cells
CANNOT DEVELOP INTO A WHOLE MUSCLE

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

what does the perimysium contain? (3)

A

nerves, blood vessels, and stretch receptors

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

tendon

A

when the endomysium, perimysium, and epimysium come together to form a connective tissue attachment to bone

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

sarcolemma

A

plasma membrane for a muscle fiber (cell)

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

sarcoplasm

A

cytoplasm of a muscle fiber

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
myofibrils
long protein cords occupying most of the sarcoplasm
26
glycogen
carbohydrate store to provide energy for exercise
27
myoglobin
red pigmented protein that binds oxygen and provides some needed for muscle activity
28
sarcoplasmic reticulum (SR)
smooth ER that forms a network around each myofibril, that stores calcium in the cell
29
terminal cisterns
dilated end-sacs of SR which cross the muscle fiber from one side to the other
30
transverse (T) tubules (2)
tubular infoldings of the sarcolemma which penetrate through the cell and emerge on the other side - funnels action potentials generated in the muscle cell towards the terminal cisterns of the SR
31
triad
a T tubule and its two associated terminal cisterns
32
myoblasts
stem cells that fuse to form each muscle fiber early in development, each contributing one nucleus
33
myosatellite cells
unspecialized myoblasts remaining between the muscle fiber and endomysium
34
three kinds of myofilaments
1. thick filaments 2. thin filaments 3. elastic filaments (titin)
35
thick filaments
made of several hundred myosin molecules
36
myosin structure (3)
- two chains intertwined to form a shaft-like tail and a double globular head - heads directed outward in a helical array around the bundle - heads on one half angle to the left, while heads on the other half are to the right
37
bare zone
middle zone with no heads
38
fibrous (F) actin
two intertwined strands of globular (G) actin subunits, each with an active site that can binds myosin
39
F actin is held together by a protein called _____ that runs along the length of the F actin strand
nebulin
40
tropomyosin
regulatory protein that blocks the active sites of G actin subunits
41
troponin
small, calcium-binding protein on each tropomyosin molecule
42
elastic filaments
made of a huge, springy protein called titin
43
what do elastic filaments do? (2)
- help stabilize and position the thick filament - prevent overstretching and provide recoil
44
where is titin located?
they run through the core of the thick filament and anchor it to Z disc and M line
45
contractile proteins
myofilaments, myosin, and actin
46
regulatory proteins
tropomyosin and troponin
47
how is contraction activated?
by the release of calcium from the SR into the sarcoplasm, binding to troponin
48
A band
dark band
49
H band
at the middle of the A band, thick filaments only
50
M line
dark, transverse protein in the middle of the H band
51
I band
light band, only thin filaments
52
Z line
protein complex that provides anchorage for thin and elastic filaments
53
sarcomere
smallest functional unit of muscles - segment from Z line to Z line
54
zone of overlap
area of the A band minus the H band
55
skeletal muscle cannot contract unless.
stimulated by a nerve
56
denervation atrophy
shrinkage of paralyzed muscle when nerve remains disconnected; motor neuron no longer stimulating the muscle cell
57
skeletal muscles are served by _____ _____ _____
somatic motor neurons
58
somatic motor neurons
nerve cells whose cell bodies are in the brainstem and spinal cord that serve skeletal muscles
59
somatic motor fibers
axons of somatic motor neurons
60
motor unit
one nerve fiber and all the muscle fibers innervated by it; they behave as a functional unit
61
muscle fibers of one motor unit..... (4)
- are dispersed throughout muscle - contract in unison - produce weak contraction over wide area - provide ability to sustain long-term contraction as motor units take turns contracting
62
effective contraction usually requires contraction of .....
several motor units at once
63
small motor units
provide fine degree of control
64
large motor units
provide more strength than control
65
neuromuscular junction (NMJ)
aka motor end plate - when a nerve fiber meets its muscle fiber target at a synapse
66
muscle cell sarcolemma have millions of what kind of receptor?
acetylcholine
67
postsynaptic membrane folds (junctional folds)
folds of the sarcolemma that increase the surface area, maximizing the number of ACh receptors
68
myasthenia gravis | a lack....
a lack of ACh receptors in muscle cells causing weakness
69
acetylcholinesterase
enzyme that breaks down ACh, allowing for relaxation
70
muscle fibers and nerve cells are what kind of cell?
electrically excitable cells
71
electrophysiology
study of the electrical activity of cells
72
electrical activity depends the concentration differences of ions in what two places?
intracellular fluid and extracellular fluid
73
polarized
contains a net negative charge
74
electrical potential/voltage
any difference in charge between two points
75
cholinesterase inhibitors
bind acetylcholinesterase and prevents it from degrading ACh
76
spastic paralysis
a state of continual contraction of the muscles; possible suffocation
77
tetanus (lockjaw)
a form of spastic paralysis caused by toxin Clostridium tetani
78
_____ in the spinal cord normally stops motor neurons from producing unwanted muscle contractions
glycine
79
what does tetanus toxin do?
blocks glycine release in the spinal cord and causes overstimulation and spastic paralysis of muscles
80
flaccid paralysis
a state in which the muscles are limp and cannot contract
81
curare
competes with ACh for receptor sites, but does not stimulate muscles
82
botulism
type of food poisoning caused by neuromuscular toxin secreted by the bacterium Clostridium botulinum
83
what does botulism toxin do?
blocks release of ACh causing flaccid paralysis
84
botox is really just
Clostridium botulinum toxin

Anatomy and Physiology I (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions