1
Q
Special functional characteristics of muscle
A
Excitability
Contractility
Elasticity
Extensibility
2
Q
Respond to stimuli
A
Excitability
3
Q
Shorten and generate pulling force
A
contractility
4
Q
Stretch w/ contraction of opposing muscle
A
extensibility
5
Q
Recoil passively after stretch
A
elasticity
6
Q
Attach to and move skeleton
• 40% of body weight
• Fibers are multinucleated
• Visible striations
• Voluntary
A
Skeletal muscle
7
Q
Found only in heart wall
• Myocardium
• Striated
• Involuntary
A
Cardiac Muscle
8
Q
Found in hollow visceral organs
• No visible striations
• Involuntary
A
Smooth
9
Q
Large complex with two identical heavy chains and two pairs of light chains.
A
Actin
10
Q
heavy chains are thin, rodlike motor proteins
A
Myosin
11
Q
motor proteins of myosin is twisted together as?
A
myosin tails
12
Q
Occupy the A band at the middle region of the sarcomere
A
Actin
Myosin
13
Q
binds both actin forming a transient cross bridge between the thick and thin filaments
A
myosin heads
14
Q
ATP catalyzing energy release during the binding of actin is called?
A
actomyosin atpase activity
15
Q
Actin is associated with?
A
Tropomyosin
Troponin
16
Q
coil of two polypeptide chains located in the groove between the two twisted actin strands
A
Tropomyosin
17
Q
3 subunits of troponin
A
Troponin T
Troponin C
Troponin I
18
Q
attaches to tropomyosin
A
Troponin T
19
Q
Binds Ca2+ to actin to move the tropomyosin
A
Troponin C
20
Q
regulates the actin myosin interaction
A
Troponin I
21
Q
Composed of actin and myosin
• Subdivided into sarcomeres
A
Myofibrils
22
Q
Envelops myofibirls
• Sarcoplasmic reticulum + T-tubules
A
Sarcotubular system
23
Q
transmits action potential
A
T system
24
Q
This contains Ca+2
A
Sarcoplasmic Reticulum
25
Triad of the sarcotubular system
2 sarcoplasmic reticulum
1 T-tubules
26
Functional unit of the myofibril
• From Z to Z disk
Sarcomere
27
Parts of the Sarcomere
1. Z disk 4. H band
2. I band 5. M line
3. A band. 6. Titin
28
framework of the sarcomere
Z to Z disk
29
this contains thin filaments (actin) only
I band
30
entire length of the thick filament; contains thick + thin filaments
A band
31
This contains the thick filaments (myosin)
only
H band
32
helps organize, align thick filaments
M line
33
tethers myosin to Z disk
*Hexagonal lattice arrangement of fibers
Titin
34
if muscle contracts what happens to the sarcomere
shortens
35
explains muscle contraction when thick and thin filaments of the muscle slides through
"Sliding filament theory"
36
Which part/s of the sarcomere becomes shorter when the sarcomere contracts?
H band
I band
Z-Z distance
37
Which part/s of the sarcomere stays the same when the sarcomere contracts?
A band
M line
Z line
38
the process by which depolarization of muscle fiber initiates contraction
Excitation-contraction coupling
39
explain the Excitation-contraction coupling-
**Action potential** travels the **neuromuscular junction** papunta sa muscle fiber. Once it reaches the **Sarcolemma** mag rerelease ang **SR ng Ca+2**, tapos ung Ca+2 mag iinitiate ng **myosin and actin interaction** causing the muscle to contract. Tapos babalik ang Ca+2 sa **SR causing muscle relaxation**
40
Cytoplasm of the skeletal muscle
sarcoplasm
41
Plasma membrane of the skeletal muscle
sarcolemma
42
Sarcolemma forms deep tubular invaginations called?
T-tubules
43
SER (Smooth endoplasmic reticulum) of the skeletal muscle
Sarcoplasmic Reticulum
44
they form a triad in the skeletal muscle
Sarcoplasmic reticulum
T-tubules
45
Muscle fiber is taken up by contractile proteins called?
Myofibrils
46
The myofibrils is divided into segments called?
sarcomeres
47
contractile units of the muscle
sarcomere
48
Marks the sarcomere boundary
Z disk
49
the sarcomere is composed of overlapping?
think and thin filaments
50
are long tubes are continuous with the plasma membrane.
T-tubules
51
Forms a dilated structure terminal cisternae which encircile myofibrils. Sequesters and releases calcium ion
SR (Sarcoplasmic Reticulum)
52
Tubules flanked by 2 terminal cisternae.
Located at Al junction. Provides uniform contraction throughout muscle fiber
Triad
53
This covers the entire muscle
Epimysium
54
Covers the fascicle
Perimysium
55
this covers each of the muscle fiber
Endomysium
56
Enumerate the layers of the muscle
Skeletal Muscle Myofibril
Fasciculus Sarcomere
Muscle Fiber Myofilaments
57
External to muscles, bones, other organs
Fascia
58
it covers the layer under the skin
Superficial fascia
59
Surrounds deeper organs, including epimysium of muscle
Deep fascia
60
Tubelike tunnel around tendon of muscle;
lined with synovial membrane
Tendon sheath
61
Surrounds entire muscle organ
Epimysium
62
Surrounds a fascicle (bundle) of muscle fibers
Perimysium
63
Surrounds an individual muscle fiber
Endomysium
64
Cell of the muscle
Muscle fiber
65
muscle fibers that shows cross striations of alternating light and dark bands
Longitudinally sectioned
66
how much myofibrils does muscle fiber contain?
hundred to thousand myofibrils
67
long filamentous bundles running parallel to the long axis of the fiber
• consist of end to end repetitive arrangement of sarcomeres
Myofilaments
68
2 types of myofilaments
Actin
Myosin
69
Types of skeletal muscle
1. Red/Slow (Type I)
2. Red/Fast (Type IIa)
3. White/Fast (Type IIb)
70
color of Type I skeletal muscle
Red
71
color of Type IIa skeletal muscle
White
72
color of Type IIb skeletal muscle
White
72
contraction time of Type I skeletal muscle
Slow
73
contraction time of Type IIa skeletal muscle
Fast
74
contraction time of Type IIb skeletal muscle
Very fast
75
Types of skeletal muscle that has a high oxidative capacity
Type I
Type IIa
76
types of skeletal muscle that has a high mitochondrial capacity
Type I
Type IIa
77
types of skeletal muscle that has a high resistance fatigue
Type I
78
types of skeletal muscle that has a medium resistance to fatigue
Type IIa
79
types of skeletal muscle that has a low resistance fatigue
Type IIb
80
Major fuel storage of Type I skeletal muscle
TAG
81
Major fuel storage of Type IIa and IIb skeletal muscle
Glycogen, creatine phosphate
82
Metabolic pathway of Type I skeletal muscle
Aerobic
83
Metabolic pathway of Type IIb skeletal muscle
Anaerobic
84
Metabolic pathway of Type IIa skeletal muscle
Both Aerobic and Anaerobic
85
force production of Type I skeletal muscle
Low
86
force production of Type IIa skeletal muscle
Medium High
87
force production of Type IIb skeletal muscle
Very High
88
Typical use of Type I skeletal muscle
Low-level contraction
89
Typical use of Type IIa skeletal muscle
Speed, strength, power
90
Typical use of Type IIb skeletal muscle
short, fast, burst of power
91
Bundles form thick myocardium
Cardiac muscle
92
Cells branch and join at intercalated discs
Cardiac muscle
93
in cardiac muscle what do you call its “fibers”
Cells
94
each cell! (muscle cells beat separately even without any stimulation)
Inherent rhythmicity
95
In cardiac muscle it is poorly defined, contributes to diads
Sarcoplasmic Reticulum
96
It consist of one T-tubule and one SR
Dyads
97
form end-to-end attachments between adjacent cardiac cells
Intercalated Disks
98
Modified cardiac muscle cells
Specialized for conduction
• Contains few myofibrils
• Large, pale filled with glycogen
Purkinje fibers
99
Where are the purkinje fibers located?
AV bundle of His
100
Muscles are spindle-shaped cells
one central nucleus
• Grouped into sheets
• No striations (no sarcomeres), no t-tubules
Smooth muscle
101
How are the smooth muscle’s thick and thin filaments arranged?
Diagonally
102
In the smooth muscle it can be found in the sarcolemma
Caveolae
103
Contractions are slow, sustained and resistant to fatigue
• Peristalsis
• Does **not always** require a nervous signal: can be stimulated by stretching or hormones
Smooth Muscle
104
functions the same as Z band
Dense Bodies
105
Filaments attach to dense bodies and stretch from one dense body to another
Smooth muscle
106
In smooth muscle it is the protein used to bind Calcium
Calmodulin
107
Explain the contraction of Smooth muscle
Histology
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