Muscles Flashcards
1
Q
Sarcolemma
A
Plasma membrane of muscle cells
2
Q
Sarcoplasm
A
Cytoplasm of muscle cells
3
Q
Muscle tissue vascularized?
A
Yes
4
Q
Mostly cells or extracellular matrix?
A
Mostly cells
5
Q
Does skeletal have striations?
A
Yes
6
Q
Skeletal–voluntary or involuntary?
A
Voluntary
7
Q
What is a myofilament?
A
Filaments of myofibrils, constructed from proteins, ex: actin and myosin
8
Q
Skeletal–contracts rapidly, tires easily
A
True
9
Q
Skeletal–nuclei peripherally located in cells
A
True
10
Q
Cardiac–
A
Doesn’t tire, interdigitate, involuntary
11
Q
Cardiac–own pacemaker
A
Heart beats without stimulation from nervous system
12
Q
No striations
A
Smooth
13
Q
Striated
A
Skeletal and cardiac
14
Q
Hollow organs
Slow, sustained contractions move fluid
Involuntary
A
Smooth
15
Q
Which one makes muscle tissue unique?
Excitability (responsiveness to stimulus)
Contractility (shorten fully upon stimulation)
Extensibility extension or stretch even beyond resting length
Elasticity (can recoil and relax back to resting length)
A
Contractility
16
Q
Excitability
A
(responsiveness to stimulus)
17
Q
Contractility
A
Shorten forcefully upon stimulation
18
Q
Extensibility
A
Extend or stretch even beyond resting length
19
Q
Elasticity
A
Ability to resume resting length after stretching
20
Q
Produce movement
Posture and position against gravity
Stabilize joints
Generate heat via contraction
A
Muscle function
21
Q
Forms valves
A
Smooth
22
Q
Dilates/constricts pupils of eyes
A
Smooth
23
Q
Forms arrector pili muscles attached to hair follicles
A
Smooth
24
Q
Muscles are demanding
A
Arteries supply oxygen and nutrients because high demand
Veins eliminate wastes (great quantities)
25
Connective tissue covers each...?
Fiber (muscle cell)
26
Dense irregular connective tissue wraps entire muscle
Epimysium
27
Dense irregular connective tissue surrounds fascicles
Perimysium
28
Loose areolar connective tissue surrounds each fiber (cell)
endomysium
29
Sheaths continuous with
Each other and tendons
29
Sheaths continuous with
Each other and tendons
30
Muscle fibers contract to pull on sheaths
Sheaths transmit force to bones
31
Origin
Less movable bone
32
Insertion
Movable bone
33
Direct (fleshy) epimysium fused to
Periosteum(bone) or perichondrium (cartilage)
34
Indirect rope-like tendon or sheet like aponeurosis connects muscle to
Connective tissue covering of bone, cartilage, or other muscles
35
Under sarcolemma
Multiple nuclei
36
Granules stored glycogen muscles can break down to glucose and produce atp
Glycosomes
37
Red pigment stores oxygen, similar to hemoglobin
Myoglobin
38
Dark bands
A bands
39
Light bands
I bands
40
Contactile unit
Z disk to z disk
41
Muscle contraction requires
Myofibrils
Sarcoplasmic reticulum
T tubules
42
Protein (heads/warts stick off protein in cross bridge cycle
Myosin
43
Run out of ATP
Muscle contracts indefinitely
| Rigor mortis
44
Protrusion of sarcolemma (membrane)
T tubules
45
Triad
T tubule surrounded by 2 terminal cisterns
46
Regulates Ca levels in muscle
Sarcoplasmic reticulum (smooth endoplasmic reticulum of cells)
47
Neuromuscular junction
located at midway point
Each muscle fibers only has one
48
3 parts of neuromuscular junction
Axon terminal
Synaptic cleft
Junctional folds of sarcolemma
49
Voltage channels respond to end plate by opening, Na into muscle cell
Action potential spreads around entire membrane, ripple effect
Depolarization
50
Na channels close
Voltage gated K channels open
K flows out of cell
Repolarization
51
Block actin and myosin to bind together
Proteins
52
What makes protein unblock troponin and tropomyosin?
Calcium frees up active site
53
Cross bridge cycling is dependent on?
ATP
54
Action potential effect shorter or longer than action potential itself?
Longer
55
Sarcopenia
Around age 30 muscle loss
56
One motor neuron and all muscle fibers it innervates
Motor unit
57
How many neuromuscular junctions per fiber?
1
59
Why are smallest motor units activated first?
Delays fatigue
60
3 types of atp production
direct phosphorylation
fermentation (aerobic glycolysis)
aerobic respiration
61
direct phosphorylation
creatine phosphate converts ADP to ATP
62
anaerobic glycolysis (fermentation)
glycogen broken down to glucose and oxidized to produce ATP
Inefficient (2 ATP per glucose), but fast
During vigorous exercise, bulging muscles constrict blood vessels, oxygen delivery is reduced
Waste product is lactic acid
ATP + CP + fermentation can power strenuous muscle activity for about 1 minute
63
aerobic respiration
mitochondria
efficient, but slow
32 atp per glucose, but O needed
64
3 consequences aerobic exercise
more capillaries surrounding muscle fibers
more mitochondria
fibers synthesize more myoglobin
65
consequences of anaerobic exercise
muscle cells grow in size (not number) and contain myofibrils
more mitochondria
more glycogen stores
more connective tissue between cells
66
muscle fatigue
inability for a muscle to contract even if it receives stimulus
67
2 not causes of muscle fatigue
NOT atp depletion
| probably NOT lactic acid
68
2 possible causes of muscle fatigue
problems with excitation-contraction coupling
| ionic imbalances, so sarcoplasmic reticulum cannot send more calcium ions
69
Its oxygen reserves in myoglobin must be replenished
muscle returns to normal
70
lactic acid reconverted to pyruvic acid
muscle returns to normal
71
Glycogen stores replaced
muscle returns to normal
72
ATP and creatine reserves must be resynthesized
muscle returns to normal
73
body must repay oxygen
oxygen debt
74
where do sheets of smooth muscle appear?
all but smallest blood vessels (capillaries), respiratory, digestive, urinary, and reproductive hollow organs
75
contraction and relaxation mixes and squeezes contents through lumen
peristalsis
76
muscle fibers run parallel to long axis of organ
| contraction shortens organ
longitudinal layer
77
muscle fibers run around organ's circumference
| contraction constricts lumen (cavity inside)
circular layer
78
Muscles work in groups of
2
79
insertion
muscle attached to movable bone
80
origin
muscle attached to immovable bone
81
main muscle moving
prime mover/agonist
82
help prime mover
| extra force, reduce undesirable movement
synergists
83
Immobilize bone/origin so prime mover has a stable base on which to act
fixators
84
oppose or reverse a movement
antagonist
85
agonist is active, antagonist is relaxed or stretched
| Located on opposite side of joint from agonist
Antagonist responsibilites
86
muscle power relies mainly on...
number of muscle fibers (cells) in muscle
87
muscle on anterior side of joint produces...
flexion
88
muscle on posterior side of joint produces....
extension
89
muscle on lateral side of joint
abduction
90
muscle on medial side of joint
adduction
91
brevis
short
92
rectus
fibers run parallel to line
93
transversus
fibers run at right angles to line
94
oblique
fibers run obliquely to line
95
Fascicles arranged in concentric rings; e.g.,: sphincters
circular muscle fiber arrangement
96
lever
bone
97
fulcrum
joint
98
effort
muscle contraction
99
load
bone, surrounding tissue, other things being moved
100
speed levers (common in body) have what disadvantage
mechanical (require more effort than object is heavy)
101
Where a muscle inserts relative to the joint (fulcrum) dramatically impacts how much (blank) the muscle must generate to move a load.
fulcrum
102
levers most common in body
3rd class lever (ex: tweezers)
103
power levers (extremely uncommon; ex: move head up and down)
slower, more stable than speed levers
104
review major muscles slide
yes
105
review excitation-contraction coupling steps
yes
