Skeletal Muscle tissue Flashcards
(103 cards)
1
Q
What are 4 functions of skeletal muscle
A
- Voluntary movement 2. Sphincters regulate release of urine and feces 3. Body temperature regulation 4. Protection
2
Q
What are 5 characteristics of muscle tissue
A
- Excitability 2. Conductivity 3. Contractility 4. Extensibility 5. Elasticity
3
Q
Excitability
A
exhibits a resting state from which it can be excited
4
Q
Conductivity
A
able to receive/carry impulses
5
Q
Contractility
A
able to forcibly shorten from resting length
6
Q
Extensibility
A
Able to extend beyond resting length
7
Q
Elasticity
A
returns to resting length following shortening/lengthening
8
Q
What are the levels of organization of a muscle
A
- Muscle 2. Fascicle 3. Muscle fiber 4. Myofibrils 5. Myofilaments
9
Q
Muscles contain
A
Fascicles
10
Q
Fascicles contain
A
Muscle fibers
11
Q
Muscle fibers contain
A
Myofibrils
12
Q
Myofibrils contain
A
Myofilaments
13
Q
Muscles are surrounded by
A
Epimysium
14
Q
Fascicles are surrounded by
A
Perimysium
15
Q
Muscle fibers are surrounded by
A
Endomysium
16
Q
What are the 2 types of muscle tissue attachments
A
- Tendons 2. Aponeurosis
17
Q
Tendon
A
Cord of dense regular CT
18
Q
Tendons attach
A
muscles to bone
19
Q
Aponeurosis
A
Thin sheet of CT
20
Q
Aponeurosis attach
A
muscles to bone and sometimes other muscles
21
Q
Point of origin
A
Less moveable site of attachment for a muscle
22
Q
Point of insertion
A
More moveable site of attachment
23
Q
What is the plasma membrane of a muscle cell
A
sarcolemma
24
Q
What carries electrical impulse in a muscle cell
A
t-tubules
25
Where are t-tubules found
attached to the sarcolemma
26
What is the cytoplasm of a muscle cell
sarcoplasm
27
What are the thick bundles of proteins capable of contracting muscle cells
myofibrils
28
What are the 2 types of myofibrils
1. Thick filaments 2. Thin filaments
29
Thick filaments
composed of myosin
30
Thin filaments
composed of actin, troponin, and tropomyosin
31
What stores and releases calcium in muscle cells
Sarcoplasmic reticulum
32
Because muscle cells have high energy demand they have lots of what 4 things
1. Mitochondria 2. Myoglobin 3. Glycosomes 5. Creatinine phosphate
33
Myoglobin
binds oxygen
34
Glycosomes
stores glucose
35
Creatinine phosphate
used for immediate energy
36
Each thick myofilament has two ____ and two _____ wrapped around each other
heads and tails
37
Thick myofilaments have binding sites for ____ and ____
actin and ATP
38
The binding site for myosin on thin myofilaments is located on
actin
39
What protein in thin myofilaments is used to prevent binding when at rest
tropomyosin
40
What protein in thin myofilaments is used to expose binding sites on actin to allows binding
Troponin
41
When myosin binds to actin what happens
muscle contraction
42
What is the basic contractile units of muscle
Sarcomere
43
What gives muscles its striated appearance
sarcomere
44
What is the ends of the sarcomere
Z disc
45
Muscle fibers exhibit
Resting membrane potential
46
Resting Membrane Potential
resting state exhibited by excitable cells
47
RMP of a muscle cell at rest
-90 mV
48
A muscle membrane is considered _____ at rest
polarized
49
Skeletal muscles fibers at rest have a high concentration of ____ and ______
extracellular sodium and intracellular potassium
50
The inside of a skeletal muscle fiber at rest is
negatively charged
51
Where is intracellular calcium stored
sarcoplasmic reticulum
52
Sarcomeres are in a ______ state when the muscle fiber is at rest
relaxed
53
Skeletal muscle is innervated by
somatic motor neurons
54
Motor unit
single somatic motor neuron and all muscle fibers it servers
55
Smaller motor units =
more control
56
Larger motor units =
less control
57
The specific location where a motor neuron innervates a muscle cell
Neuromuscular junction
58
What are the 3 components of a NMJ
1. Synaptic knob 2. Synaptic cleft 3. Motor end plate
59
Synaptic knob
end of somatic motor neuron
60
Synaptic cleft
space between neuron and muscle cell
61
Where are neurotransmitters released
Synaptic cleft
62
Motor end plate
region of sarcolemma that contains neurotransmitter receptors
63
In the termination of muscle contraction what enzyme is release to breakdown ACh in the synaptic cleft
Acetylcholinesterase
64
In the termination of muscle contraction calcium returns where
Sarcoplasmic reticulum
65
In the termination of muscle contraction ______ returns to relaxed state
sarcomeres
66
Muscle cells can only store enough ATP for how much activity
5 seconds
67
What are the 3 ways to generate ATP in skeletal muscle
1. Immediate supply via phosphate transfer 2. Short-term supply via glycolysis 3. Long-term supply via aerobic cellular respiration
68
Immediate supply via phosphate transfer provides how much energy
10 seconds
69
What two sources can provide a phosphate for Immediate supply
1. Creatinine phosphate 2. ADP
70
Does Immediate supply require oxygen
No
71
How many ATP are produced from immediate supply
1
72
How much energy does short-term supply provide
60 seconds
73
Short-term supply is also known as
glycolysis
74
Short-term supply converts glucose to
pyruvate
75
Does glycolysis require oxygen
No
76
How many ATP does short-term supply provide
2
77
How much energy does long-term supply provide
from the 50-60 second mark until contraction ends
78
Where does long-term supply occur
mitochondria of cells
79
What is long-term supply also known as
cellular respiration
80
What does long-term supply break down
pyruvate
81
Does long-term supply require oxygen
yes
82
How many ATP does long-term supply yield
30
83
Oxygen debt
amount of oxygen needed to restore muscle to resting conditions
84
Why does oxygen debt occur
the body's demand for oxygen exceeds the body's ability to deliver it to the cells
85
Muscle fibers are classified by what 2 criteria
1. Type of contraction generated 2. Means of supplying ATP
86
What are the 2 types of classifications under type of muscle contraction generated
1. Slow-twitch fibers 2. Fast-twitch fibers
87
What are the 2 types of classifications under means of supplying ATP to muscle
1. Oxidative fibers 2. Glycolytic fibers
88
What are the 3 types of muscle fibers
1. slow oxidative fibers (red) 2. Fast glycolytic fibers (white) 3. Fast oxidative fibers (pink)
89
Slow oxidative fibers or "marathon" fibers use mostly _______ means of ATP production
aerobic
90
Slow oxidative fibers are _______ to fatigue
slow
91
Fast glycolytic fibers use mostly ______ means of ATP production
anaerobic
92
Fast glycolytic fibers are ______ to fatigue
quick
93
What type of exercise results in increased muscle vascularization, increased # of mitochondria, and stimulates myoglobin synthesis
Cardiovascular exercise
94
what type of exercise results in muscle hypertrophy, increased strength, increased endurance, and increased bone density
Resistance exercise
95
Little/no exercise leads to muscle ______
atrophy
96
The overload principle
forcing a muscle to work hard promotes increased muscle strength and endurance
97
What are the 2 types of muscle contraction
1. Isometric contraction 2. Isotonic contraction
98
Isometric contraction
muscle contracts but produces no movement
99
Isotonic contraction
muscle contracts and produces movement
100
What are the 2 types of Isotonic contraction
1. Concentric 2. Eccentric
101
Concentric
Shortens
102
Eccentric
lengthens
103
Calcium binds to ______ to displace tropomyosin and expose binding sites on actin
troponin
