Chapter 5: Muscular Tissue Flashcards
1
Q
What comprises the majority of the “flesh” (sarcos, Gr. flesh) or “meat” of an organism. It is also a primary mural (wall) element of tubular organs.
A
Muscle
2
Q
Muscle fibers are enclosed by ? (the combined plasmalemma and basal lamina) and fine reticular fibers
A
sarcolemma
3
Q
What contains typical organelles as well as contractile elements?
A
sarcoplasm or cytoplasm
4
Q
What are myofilaments composed of proteins, actin (containing thin filaments) and myosin (containing thick filaments)
A
contractile elements
5
Q
The myofilaments are grouped as?
A
myofibers
6
Q
What cells are often called muscle fibers or myofibers because they are elongate cells with spindle-shaped fiber-like profiles?
A
Muscle cells
7
Q
This type of muscle tissue is non-striated, involuntary
A
Smooth muscle
8
Q
This type of muscle tissue is striated, voluntary
A
Skeletal muscle
9
Q
This type of muscle tissue is striated, involuntary
A
Cardiac muscle
10
Q
The cells of this muscle is thick, long, unbranched, cylindric
A
Skeletal muscle
11
Q
The cells of this muscle is branched, cylindric
A
Cardiac muscle
12
Q
The cells of this muscle is small, spindle-shaped
A
Smooth,muscle
13
Q
The nuclei per cell of this muscle is many, peripheral
A
Skeletal muscle
14
Q
The nuclei per cell of this muscle is one or 2, central
A
Cardiac muscle
15
Q
The nuclei per cell of this muscle is one, central
A
Smooth mucle
16
Q
The filament ratio of these muscles is 6 thin/one thick
A
Skeletal and cardiac muscle
17
Q
The filament ratio of this muscles is 12 thin/1 thick
A
18
Q
The Sarcoplasmic reticulum and myofibrils of this muscle is highly organized sarcoplasmic, reticulum surrounds myofibrils
A
Skeletal muscle
19
Q
The Sarcoplasmic reticulum and myofibrils of this muscle is less organized sarcoplasmic reticulum; no distinct myofibrils
A
Cardiac muscle
20
Q
The Sarcoplasmic reticulum and myofibrils of this muscle is poorly organized sarcoplasmic reticulum; no distinct myofibrils
A
Smooth muscle
21
Q
The T tubules of this muscle is at A-I band junctions; form triad
A
Skeletal muscle
22
Q
The T tubules of this muscle is at Z lines; form dyads
A
Cardiac muscle
23
Q
There’s no T tubules on this muscle
A
Smooth muscle
24
Q
Motor end-plates of this muscle is
A
25
The Motor end-plates of this muscle is present
Skeletal muscle
26
The Motor end-plates of these muscle is absent
Cardiac and smooth muscles
27
The motor control of this muscle is voluntary
Skeletal muscle
28
The motor control of this muscle is involuntary
Cardiac and smooth muscles
29
are elongated, unbranched, cylindrical, multinucleated cells. The flattened peripheral nuclei lie just under the sarcolemma (muscle cell plasma membrane); most of the organelles and sarcoplasm (muscle cytoplasm) are near the poles of the nuclei
skeletal muscle fibers
30
The sarcoplasm contains many mitochondria, glycogen granules, and an oxygen-binding protein called ?, that accumulates lipofuscin pigments with age
myoglobin
31
This myofilaments of skeletal muscle measures 6 nm in diameter, electron-luscent (visibly light band)
Thin filament (actin)
32
Muscles that contain thin filaments
actin
33
Muscles that contain thick filaments
Myosin
34
This thin myofilaments of skeletal muscle is a polymeric chain of globular actin (G-actin) monomers. Each thin filament contains 2 of F-actin strands wound in a double helix
Filamentous actin (F-actin)
35
This thin myofilaments of skeletal muscle is a long, thin, double-helical polypeptide that wraps around the actin double helix, lies in the grooves on its surface, and spans 7 G-actin monomers
Tropomyosin
36
This thin myofilaments of skeletal muscle is a complex of three globular proteins
Troponin
37
Troponin is a complex of three globular proteins. What attaches each complex to a specific site on each tropomyosin molecules?
TnT (troponin T)
38
Troponin is a complex of three globular proteins. TnT (troponin T) attaches each complex to a specific site on each tropomyosin molecules, what binds calcium ions?
TnC
39
Troponin is a complex of three globular proteins. TnT (troponin T) attaches each complex to a specific site on each tropomyosin molecules, TnC binds calcium ions, and what inhibits the interaction between the thin and thick filaments?
TnI
40
What myofilaments of muscle measures 15 nm in diameter, electron-densed (visibly dark band), is a long, golfclub-shaped polypeptide molecule. This myofilament of muscle is a bundle of myosin molecules with their shafts pointing toward and overlapping in the bundle’s middle and their heads projecting from the bundle’s ends
Thick filament (myosin)
41
Appearance of myofibrils in longitudinal section. At the light and EM levels, each myofibril exhibits repeating, linearly arranged, functional subunits called ?, which have bands (striations) running perpendicular to the long axis of the myofibril.
sarcomere
42
the planes of polarized light were refracted equally when passed through the light band regions. It is a light-staining band that contains only the thin filaments. They are called isotropic because they do not rotate polarize light. These bands is bisected by a Z line, thus, each sarcomere has 2 half I bands, one at each end.
I band (isotropic)
43
the planes of polarized light were refracted unequally when passed through the dark band regions. They are called anisotropic because it is birefringent capable of rotating polarized light. Each of these bands has a lighter central region termed H band, which is bisected by an M line.
A band (anisotropic)
44
These bands is derived from the German term “Helles” which means clear. It is a lighter staining central region of the A band that contains the M line and only the thick filaments. It lies between the free ends of the thin filaments and contains only the shaft of myosin molecules.
H band
45
What line is derived from the German term “Zwischenscheiben” which means between disks. It separates the sarcomere from its neighbors at each end. A major protein of Z disk, alpha-actinin, anchors one end of the thin filaments and helps maintain spatial distribution.
Z line, or Z disk
46
What line is derived from the German term “Mittel” which means intermediate or middle. It holds the thick filaments in place and marks the center of each sarcomere.
M line
47
This muscle cell is specialized to sequester calcium ions
Sarcoplasmic reticulum of skeletal muscle cells
48
At each I band junction, a tubular invagination of the sarcolemma termed ? penetrates the muscle fiber and comes to lie close to the surface of the myofibrils
transverse tubule or T tubule
49
On each side of the T tubule lies an expansion of the sarcoplasmic reticulum termed?
terminal cisternae
50
A complex of 2 terminal cisternae and an intervening T tubule constitutes a ? which are important in initiating muscle contraction.
Triads
51
is a collection of specialized synapses of the terminal button of the motor neuron with the sarcolemma of the skeletal muscle fiber. It transmits nerve impulses to muscle cells, initiating muscle contraction
Motor End-Plate or myoneural junction
52
This myoneural junction is the terminal bouton. The bouton contains mitochondria and acetylcholine-filled synaptic vesicles
Presynaptic (neural) component
53
The part of the bouton’s plasma membrane directly facing the muscle fiber is the?
presynaptic membrane
54
What lies between the presynaptic membrane and the apposing postsynaptic membrane and contains a continuation of the muscle fiber basal lamina
Synaptic cleft
55
Synaptic cleft contains what enzyme? which breaks down neurotransmitter so that when the neural stimulation ends, contraction ends
acetylcholinesterase
56
What cleft lies directly beneath the presynaptic membrane and communicates directly with a series of secondary synaptic clefts created by infoldings of the postsynaptic membrane
primary synaptic cleft
57
This myoneural junction includes sarcolemma (postsynaptic membrane) and the sarcoplasm directly under a synapse
postsynaptic (muscular) component
58
What membrane contains receptors for acetylcholine and is thrown into numerous junctional folds. The sarcoplasm beneath the folds contains nuclei, mitochondria, ribosomes and glycogen
postsynaptic membrane
59
60
This muscle fibers are long, branched cells with one or two ovoid central nuclei
Cardiac muscle fibers
61
This cardiac muscle fibers are small and have fewer T tubules than ventricular cells. They contain many small membrane-limited granules that contain a precursor of atrial natriuretic factor, a hormone secreted in response to increased blood volume that opposes the action of aldosterone and acts on the kidneys to cause sodium and water loss.
Atrial cardiac muscle fibers
62
This cardiac muscle fibers are large cells with more T tubules and no granules.
Ventricular cardiac muscle fibers
63
These fibers are specialized cardiac muscle cells that are modified as impulse- conducting cells. These fibers conduct impulses from the A-V node through the interventricular septum to the ventricles. In cross section, these fibers are larger than the ordinary cardiac muscle cells. They have an abundant pale-staining acidophilic sarcoplasm containing few myofibrils that are located at the periphery of the cell. In longitudinal section, these fibers appear as swollen cardiac muscle cells with scattered myofibrils.
Purkinje fibers
64
What is less organized than that of the skeletal muscle and does not subdivide myofilaments into discrete myofibrillar bundles
sarcoplasmic reticulum in cardiac muscle fibers
65
These tubules occur at the Z line instead of the A-I junction. In most cells, these tubules associate with a single expanded cisterna of the sarcoplamic reticulum
Cardiac T tubules
66
cardiac muscles contain ? instead of triads
dyads
67
What filaments of smooth muscle are like those of the skeletal and cardiac muscles
actin
68
actin filaments of smooth muscle are always present in the cytoplasm and are anchored by ? associated with plasma membrane
alpha-actinin dense bodies
69
What filaments of smooth muscle are less stable than those in striated muscle cells; they are not always present in the cytoplasm but seem to form in response to contractile stimulus
myosin
70
What muscle cells contain poorly organize sarcoplasmic reticulum that participates in the sequestration and release of Ca2+ but does not divide the myofilaments into myofibrilar bundles?
Smooth muscles cells
71
Abundant surface-associated membrane-limited ventricles termed ? appear to aid in Ca2+ uptake and release
caveola
72
What type of smooth muscle derived from splanchno-pleural mesenchyme, is found in the walls of thoracic, abdominal and pelvic organs of the respiratory, digestive, urinary and reproductive systems. In addition to thick myosin and thin actin filaments, its sarcolemma-associated dense bodies are linked by desmin- containing intermediate filaments. Contraction is slow and in waves
Visceral smooth muscle
73
Visceral smooth muscle are classed as?
unitary smooth muscle
74
What type of smooth muscles differentiates from the mesenchyme around developing blood vessels. Its cells have intermediate filaments containing vimentin as well as desmin. It has the same functional features as the visceral smooth muscle and is also classed as unitary smooth muscle, although its waves of contractions are not sustained and are localized
Vascular smooth muscle
75
The cells of this type of smooth muscle are derived from the ectoderm and have a rich nerve supply. They are classed as multi-unit smooth muscle because the cells can contract individually. They are capable of precise and graded contractions
Smooth muscle of the iris
