Muscular Tissue Flashcards
1
Q
Cell membrane of a muscle cell
A
Sarcolemma
2
Q
Cytoplasm of cell membrane
A
Sarcoplasm
3
Q
To forcefully shorten
A
Contractility
4
Q
Response to stimuli
A
Excitability
5
Q
To stretch or to extend
A
Extensibility
6
Q
To return to its normal length after stretch
A
Elasticity
7
Q
It is a rod like long contractile fiber
A
Myofibril
8
Q
Sac like membrane for contraction and relaxation
A
Sarcoplasmic reticulum
9
Q
Thick muscle contraction and cell motility
A
Thick (myosin)
10
Q
Thin muscle contraction
A
Thin (actin)
11
Q
It is attached to the bone, skin, or fascia
A
Skeletal muscles
12
Q
It is a connective tissue that seperates single muscle fibers (surrounds the muscle fibers)
A
Endomysium
13
Q
Covering of fasciculus which transmit lateral contractile (surrounds the bundle of muscle fibers)
A
Perimysium
14
Q
Allows muscle to contract and move while maintaining structural integrity (surrounds the muscle)
A
Epimysium
15
Q
Transmit mechanical action
A
Fascicle
16
Q
One muscle bundle
A
Fasciculus
17
Q
What is the nervous control of skeletal muscle?
A
CNS
18
Q
What is the appearance of skeletal muscle?
A
Single, very long, cylindrical, multinucleated with striations
19
Q
Stimulation of single muscle to contract by ANS
A
En toto or En masse
20
Q
A zone where there is no A band
A
Henzen zone
21
Q
Region of I band to I band
A
Sacromere
22
Q
What is the manner of contraction of skeletal muscle?
A
Very rapid
23
Q
Time of twitch
A
0.1 second
24
Q
Time of stimulation
A
0.01 second
25
Time of contraction
0.03 second
26
Time of relaxation
0.04 second
27
It connects the branching of myofilaments to contract at the same time
Intercalated disks
28
Cells and muscles for 1 function only
Synctium
29
What are the 2 synctia of heart?
Atrial and ventricular
30
Function of atrial synctium
To contract
31
Function if ventricular
Pump out blood
(Left - other body parts, right - lungs)
32
Appearance of cardiac muscle
Branching chains of cells, unicleated or binucleated, with striations
33
What is the nervous control of cardiac muslce
ANS
34
What happens in en toto or en masse
1. Stimulation of one muscle cell to contract by ANS
2. SA node stimulates all muscle cells of atrial synctium to contract and relax.
3. Then stimulation of AV nodes - stimulates the ventricular synctium to contract and relax
= rythmic contraction of heart
35
Nerve fibers surrounding entire ventricles
Bundle of His
36
What is SA node
Considered as pacemaker to determine beat of heart
37
Meaning of SA node
Sinoatrial node
38
Meaning of AV node
Atrioventricular node
39
Series of involuntary wavelike contraction of smooth muscles
Peristalsis
40
-Attach to hair follicles in skin
-In walls of hollow organs like blood vessels and GI tract
-non striated
Smooth muscles
41
Nervous control of smooth muscles
ANS - medulla oblongata
42
Manner of contraction if smooth muscles
-slow wave like contraction
43
What happens of manner of contraction of smooth muscles
Stimulation of initial cells to contract by ANS, then stimulated by ANS the next muscle then proceed until the last muscle cell to contract
44
What is the arrangement of myofilaments in smooth muscles
Irregularly arranged (diagonally)
45
What is attached to dense bodies?
Intermediate filament bundle
46
True or false: therr are more thick filaments in smooth muscles
True
47
There is no troponin complex in smooth muscle
Yes
48
A synapse or connection between motor neuron and muscle fiber
Neuromuscular junction
49
Are the nerves that innervate muscle fibers / or the glands
Motor neurons
50
Single motor neuron and the muscle fibers it innervate
Motor unit
51
What happens when axon approaches muscle?
It divides into terminal branches and loses its myelin sheath and form junction with one or more muscle fiber
52
It is called when the axon terminal is enlarged into a knoblike structure which fits into shallow depression in underlying muscle fiber
Terminal button
53
Where does acetylcholine came from?
Stored in synaptic vesicle
54
Where does action potential arrives? And what will happen?
It arrives in pre-synaptic terminal and cause volted gated ca2+ channels to open
55
How action potential is initiated
When the cell body has received enough excitatory signals from other neurons
56
What makes the action potential be able to open the voltage-gated ca2+ channels?
-Action potential depolarizes the membrane and opens voltage-gated channels
-Carries electrical properties which the voltage-gated channel will RESPOND TO OPEN
57
When Ca2+ uptake in terminal what does it cause
Release neurotransmitters (acetylcholine) into synaptic cleft
58
Another term for post synaptic cleft
Motor end plate
59
What does motor end plate contains? And what is it for?
It contains nicotinic receptors for acetylcholine
60
Enumerate the process of neuromuscular junction (before end plate potential)
1. Action potential arrives at pre-synaptic terminal causing the voltage-gated ca2+ channels to open.
2. Ca2+ releases neurotransmitters (acetylcholine) from synaptic vesicle to synaptic cleft
3. Ach travels across synaptic cleft to motor end plate.
4. Motor end plate contains nicotinic receptors where Ach binds
5. Ach binds to the alpha subunit of the nicotinic receptors resulting to conformational change
6. Na influx K efflux
7. Causing the central core channels to open and increase the permeability of Na+ and K+
8. Sodium enter muscle fiber
(Ach molecules combine with receptor sites cause to open ligand-gated Na+ channels *for Na+*)
61
What happens in end plate potential?
1. When the ion channels open in the posylt synaptic membrane both Na+ and K+ flow down their concentration gradient
2. In their resting potential, Na+ has more net driving force than K+
3. Ach triggers opening channels more Na+ moves inwards, K+ outwards
4. Depolarization happens
5. Called end plate potential
62
When small quanta (packets) of Ach are released randomly from nerve cell at rest, each produce smallest possible change in membrane potential of motor end plate
Miniature EPP
63
When nerve impulse reaches the ending, the number of quanta release increases by several folds
Large EPP
64
It destroyes Ach so that no new AP arise
Acetylcholinesterase
65
When the electrical respojse is turned off by AchE what will happen to Ach
Will degrade into choline and acetate
66
How many percent of choline is returned to the presynaptic terminal?
50%
67
Who is responsible for returning the 50% choline to presynaptic terminal
Na+ choline transport
68
Myosin heads bound to what?
ADP and phosphate molecule
69
What happens in sliding filament theory
1. Nerve impulse reaches muscle cells, ca2+ is released from Sr then bound to troponin - causes the tropomyosin molecule change or shift in position to expose binding sites (myosin binding site) - actin myofilament
2. Myosin heads bind to the binding sites of the actin proteins, releasing first the phosphates
3. then two filaments glide past one another, propelled by a head first movement of the myosin units then ADP released.
4. New ATP molecules bind to the myosin bind to the myosin heads causing separation of the actin-myosin cross bridge (stopping motion) then ATP goes to ADP to provide power for the myosin head.
70
It is the middle of I band and the boundary of contraction
Z disk/Z-line
71
A zone which will disappear in contraction with no A bands and I bands
Henzen zone
72
Where does sarcomere exist?
Z-line to Z-line
73
It is the dark middle band and has overlapping thick and thin filaments
A band
74
It is the end of A band with thin filaments only
I band
75
It hold the myosin filaments to the Z-line
Titin proteins
76
What does T-tubules associate with?
SR
77
What does T-tubules serve
To rapidly conduct electrical excitation and communicate with SR
78
It is composed of many myosin molecules has tail region and 2 globular heads
Thick filament structure
79
It is composed of actin protein
Thin filament structure
80
It is the protein spirals around actin helix
Tropomyosin
81
It has binding sites for myosin cross bridges
Actin filaments
