Muscle Tissue Flashcards
(119 cards)
0
Q
Smooth non-striated muscle is found:
A
In stomach, small and large intestines, erector pili(goosebumps), esophagus, uterus and Fallopian tubes.
1
Q
Smooth muscle is:
A
Non-striated and involuntary
2
Q
Smooth non-striated muscle is:
A
Involuntary
3
Q
Cardiac muscle is:
A
Striated and involuntary
4
Q
Skeletal muscle is:
A
Striated and voluntary
5
Q
Skeletal muscle is found:
A
Everywhere and mostly attached to the skeleton.
6
Q
How many functions of muscular tissue are there?
A
4
7
Q
What are the 4 functions of muscular tissue?
A
- Produces the body movement necessary for survival.
- Postural and stabilization of form.
- Storage and transferring of substances within this body. (Sphincters)
- Generating heat for thermoregulation.
8
Q
How does muscular tissue produce the body movements for human survival?
A
Walking, running, manipulation of things, talking, etc…
9
Q
How does muscle tissue create postural stability and stabilization of form?
A
Muscles keep your spine erect, your head up, your bones padded.
10
Q
How does muscular tissue store and transfer substances within the body?
A
Muscles store ions, glycogen (body’s stored form of energy), and enzymes used throughout the body during normal metabolism. Also muscles act as gate keepers to regulate movement of substances from one storage area to the next.
11
Q
What type of muscle acts as a gate keeper for storing and transferring substances in the body?
A
Sphincters.
12
Q
How does muscular tissue generate heat for thermoregulation?
A
Heat is released as a by product of normal muscle metabolism. Shivering is an involuntary response of skeletal muscle to generate body heat to raise body temperature when the environment is cold.
13
Q
What is interesting about shivering?
A
Shivering is an involuntary response using voluntary muscles!
14
Q
What are the 4 key properties of muscle tissue?
A
- Excitability
- Contractibility
- Extensibility
- Elasticity
15
Q
What is excitability in regards to muscle tissue?
A
Excitability is a key property of muscle tissue. Excitability is the ability to be stimulated. Electrical signals from the nervous system, hormonal signals, and chemical signals such as pH changes will cause excitability and generation of Action Potentials.
16
Q
What is contractibility in regards to muscle tissue?
A
Contractibility is a key property of muscle tissue. Contractibility is the ability to shorten and contract. This in turn translates force onto attached tendons and bones to generate movement.
17
Q
What is extensibility in regard to muscle tissue?
A
Extensibility is a key property of muscle tissue. Extensibility is the ability to stretch and lengthen without damage to its own tissue. This is due to the nature do the muscle fibers as well as elastic and collagen fibers.
18
Q
What is elasticity in regard to muscle tissue?
A
Elasticity is a key property of muscle tissue. Elasticity is the ability of tissue to return to it’s original length, size and form after normal muscle contraction.
19
Q
What is periosteum and how is it connected to muscular tissue?
A
Periosteum is the layer of dense irregular connective tissue that acts as skin for the bone and surrounds the tendon of the muscle. It blends into the synovial tendon sheath.
20
Q
What is fascia?
A
Fascia is fibrous connective tissue that surrounds muscles. Fascia consists of 2 layers.
21
Q
What are the 2 layers of fascia?
A
- Superficial fascia.
2. Deep “investing” fascia.
22
Q
What is superficial fascia?
A
Superficial fascia separates muscle from the skin. It is the layer we encounter beneath the dermis and epidermis. Superficial fascia is also known as the subcutaneous layer or the hypodermis layer.
23
Q
What in worth noting about the subcutaneous layer or hypodermis layer of superficial fascia?
A
The superficial layer or hypodermis layer of fascia is densely packed with nerves, blood vessels, adipose tissue, connective tissue and lymphatic vessels.
24
What is deep or investing fascia?
Deep or investing fascia surrounds a muscle or a group of muscles and lines body walls. It allows for free movement of muscles and fills the space between individual muscles.
25
What is epimysium?
Epimysium is the tissue layer that encircles the entire muscle belly. It is dense irregular connective tissue)
26
What is perimysium?
Perimysium encircles a group of muscle fibers or fascicles. It is dense irregular connective tissue.
27
What is a fascicle?
Fascicles are groups of muscle fibers, aka a bundle of 10 or more muscle fibers.
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what is endomysium?
Endomysium is the tissue layer that encircles and separates each individual muscle fiber or cell within a fascicle.
29
What are tendons?
Tendons are dense regular connective tissue that extends from the muscle to attach to the bone. It can be continuous with epimysium, perimysium, and endomysium. They are shaped as long, cylindrical and tubular.
30
What is an aponeurosis?
Aponeurosis are similar to a tendon, but is broad, thin and flat. It is also dense regular connective tissue. It like tendons serves to attach muscles to bones.
31
What are synovial tendon sheaths?
Synovial tendon sheaths are skin for tendons. In certain areas of the body tendons are subject to high levels of stress, therefore require an extra layer of connective tissue to prevent wear and tear.
32
What is muscle fiber?
Muscle fiber is muscle cell. It stores each of the individual muscle filaments. (Thick and thin)
33
How do muscle fibers develope?
Muscle fibers develop from myoblasts, the fundamental cells in muscles.
34
What is hypertrophy?
Hypertrophy is an increase in the size of a muscle.
35
What is hyperplasia?
Hyperplasia is the an increase in the number of fibers or cells of a muscle. Growth by Cellular division.
36
What is atrophy?
Atrophy is the loss of myofibril a and therefore loss in the size if a muscle.
37
What is fibrosis?
Fibrosis occurs when there is damage to a muscle and scar tissue is layer down to replace the damaged cells and tissue.
38
What is a satellite cell?
A satellite cell is a remnant my oblast cell that persists in limited numbers to help with muscle repair. Satellite cells may still undergo mitosis to create more satellite cells.
39
What is a myoblast?
A myoblast cell is an immature muscle cell derived from mesenchymal cells that may fuse with each other to form a mature muscle fiber. Some may persist as satellite cells.
40
What is sarcolema?
Sarcolema is the plasma membrane of a muscle cell.
41
What is sarcoplasm?
Sarcoplasm is the cytoplasm of the muscle cell or muscle fiber.
42
What is myoglobin?
Myoglobin is a protein found only in muscle fiber. It binds with O2 when needed for ATP production.
43
What are myofibrils?
Myofibrils are contracting organelles of a skeletal muscle cell. These structures are the ones responsible for muscle contraction.
44
Muscle cells contain many triads. What are these triads composed of?
The muscle cell triads are composed of transverse tubules, and 2 terminal cisternaes.
45
What is a transverse tubule?
A transverse tubule is a tiny invagination of the sarcolemma.
46
What is a terminal cisternae?
A terminal cisternae is an enlargement of the sarcoplasmic reticulum.
47
What is the sarcoplasmic reticulum?
The sarcoplasmic reticulum is the smooth membranous sac than encircles and surrounds each myofibril. It's main job is to release and store calcium into the sarcoplasm to help with muscle contraction.
48
What is the sarcoplasmic reticulum's main job?
The sarcoplasmic reticulum's main job is to store and release calcium into the the sarcoplasm to help with muscle contraction.
49
What are filaments?
Filaments are found in the myofibril, to the organelle of a sarcomere. There are 2 types.
50
What are the 2 types of filaments found I the sarcomere?
The 2 types of filaments found in the sarcomere are thick filaments and thin filaments.
51
What is a thick filament of the sarcomere?
A thick filament is made up of myosin and is 16nm wide.
52
What is a thin filament of the sarcomere?
A thin filament of the sarcomere is made up of actin, troponin & tropomyosin proteins.
53
How are the the thick and thin filaments arranged?
The thick and thin filaments are in a staggered pattern within a sarcomere from z line to z line.
54
How many types of muscle proteins are there?
There are 3 muscle proteins.
55
What are the three muscle proteins?
The three muscle proteins are:
1. Contractile
2. Regulatory
3. Structural
56
What are the contractile muscle proteins?
The contractile muscle proteins are myosin and actin. Myosin are the thick filaments with golf club like heads and actin are the thin filaments with the binding sites for myosin.
57
What are the regulatory muscle proteins?
The regulatory muscle proteins are troponin and tropomyosin.
58
What are the structural muscle proteins?
The structural muscle proteins are titin, myomesin, nebulin, and dystrophin.
59
What is myosin?
Myosin is a contractile muscle protein. It makes up the thick filament of a sarcomere and is shaped like golf clubs. The clubs bind into the thin filament and moves along the thin filaments of actin.
60
What is actin?
Actin is a contractile muscle protein that has binding sites for myosin.
61
What is troponin?
Troponin is a regulatory muscle protein found on thin filaments. Troponin assists tropomyosin in blocking myosin binding sites during relaxation.
62
What is tropomyosin?
Tropomyosin is a regulatory muscle protein found on thin filaments. It assists in blocking the myosin binding sites during relaxation.
63
What is titin?
Titin is a structural muscle protein. Titin is the 3rd most plentiful structural muscle protein. It anchors a thick filament from m-line to z-disc. It helps return the filaments to the original positions after a full stretch or contraction.
64
What is myomesin?
Myomesin is a structural muscle protein that forms the M line and helps to stabilize the thick filaments.
65
What is nebulin?
Nebulin is a structural muscle protein that helps anchor the thin filaments to the Z discs.
66
What is dystrophin?
Dystrophin is a structural muscle protein that helps to link thin filaments to the sarcolemma for stability.
67
Which structural muscle protein is lacking in the pathology Muscular Dystrophy?
Dystrophin.
68
What are the features of the anatomy of a sarcomere?
```
A-band
I-band
Z-discs, Z-line
M-line
H-zone
```
69
What is the A-band?
The A-band of a sarcomere is the entire length of thick filaments with ends overlapping thin filaments. ("A" in dark because of both types of filaments overlapping each other)
70
What is the I-band?
The I-band of the sarcomere is light because of thin filaments only (actin), no thick filaments. (I in light, not dark. No thick filaments)
A Z-line passes through the centre of each I band.
71
What are Z- discs and Z-lines?
Z-discs are protein structures located on the Z-line that stabilize the filaments.
Z-lines are the lines that dictate the terminal ends of 1 sarcomere unit.
72
What is the M-line?
The M-line is the exact middle of the sarcomere. The Midline. It passes through the middle of the thick filaments.
73
What is the H-zone?
The H-zone is the middle portion of the A-band of thick filaments only, no thin filaments.
74
What happens with the various zones of the sarcomere during muscle contraction?
1. Z-lines/discs come closer together as the sarcomere shortens.
2. H-zone shrinks/disappears.
3. I-band shrinks
4. A-band remains the same size. It never changes length!
75
What are the 4 steps to the sliding filament theory?
1. ATP hydrolysis.
2. Formation of cross bridges.
3. Power stroke.
4. Breaking of the cross bridges.
76
What is ATP hydrolysis?
ATPase cleaves ATP into ADP and releases a high energy P+(phosphate) group.
77
How does the formation of the cross bridges occur?
Ca+2 (calcium) from the sarcoplasmic reticulum binds to troponin, changes the troponin-tropomyosin complex and slides tropomyosin out of the way to allow myosin and actin to bind.
78
What happens during the power stoke?
During the power stroke, the cross bridge rotates towards the centre of the sarcomere and slides the complex towards the middle.
79
What occurs during the breaking of the cross bridges?
A new molecule of ATP binds to the cross bridge, causing release of the myosin from actin. Then the cycle begins again!
80
What is ACh?
ACh is acetylcholine.
81
Muscles contract due to what?
Muscles contract due to a rapid influx of calcium from the sarcastic reticulum.
82
What is an Action Potential?
An action potential is an electrical signal that causes changes to the membrane which causes different channels to open and close which in turn releases chemicals needed for a specific physiological response.
83
What are somatic motor neutrons?
Somatic motor neutrons are nerves that extend from the brain and the spinal cord that are responsible for body movement.
84
What is the neuromuscular junction?
The neuromuscular junction is a location on the sarcomere of a muscle fiber where the somatic motor nerves for the brain and spinal cord end. The synapse between the axon of a neuron and the muscle fiber. It is the junction where nerves and muscle meet.
85
What is the synaptic cleft?
The synaptic cleft is a minute/micro gap that separates the axon terminal and the muscle. "Synapse" applies to this cleft and how nerves communicate or connect with one another.
86
What is a neurotransmitter?
A neurotransmitter is a hormone or special chemical that sends the action potential or electrical impulse across the the synaptic cleft from the nerve to the muscle.
87
What is ACh or acetylcholine?
Acetylcholine is the main neurotransmitter that occurs at the neuromuscular junction. It is stored in synaptic vessels on the axon terminal side of the neuromuscular junction.
88
Where is acetylcholine stored?
Acetylcholine is stored in synaptic vessels on the axon terminal side of the neuromuscular junction.
89
What is the motor end plate?
The motor end plate is the side of the muscle sarcolemma that contains ACh receptors. ACh receptors are ligand-gated receptors. The motor end plate is also known as the post synapse side. "After the synaptic cleft"
90
How many steps are involved in the generation of the Action Potential and what are they?
There are 4 steps involved in the generation of the action potential. They are:
1. Release of ACh.
2. Activation of ACh.
3. Production of the AP.
4. Termination of ACh.
91
How does the release of ACh happen?
The Action Potential arrives at the axon terminal causing the stored acetylcholine vesicles to exocytose into the synaptic cleft and release the acetylcholine which then diffuses toward the motor end plate.
92
What happens during the activation of ACh receptors?
Acetylcholine binds to their corresponding receptor on the motor end plate and this in turn opens sodium channels, causing sodium to flow into the membrane (sarcolemma) of the muscle. Because sodium is mostly on he outside of the cell,when the channels open, sodium floods from the outside to the inside of the cell and this changes the electricochemical gradient which helps to create the Action Potential.
93
How is the Action Potential produced?
Because sodium is mostly on he outside of the cell,when the channels open, sodium floods from the outside to the inside of the cell and this changes the electricochemical gradient which helps to create the Action Potential. A post synaptic Action potential is generated and propagates along the sarcolemma in both directions, into the muscle T-tubule system and causes a secondary release of calcium for the sarcoplasmic reticulum. The calcium binds onto the troponin causing the the tropomyosin to slide out of the way so that the myosin can bind to the actin and cause the muscle fibers to slide past on another and hence contract.
94
How does the termination of ACh (acetylcholine) occur?
ACh (acetylcholine) is broken down by an enzyme called acetylcholinesterase NAND the end products are recycled back into the axon terminal to make new ACh molecules for the next time it is needed.
95
Where is the muscle innervated by the neuromuscular junction?
The NMJ tends to innervate the middle of the muscle to allow the impulses to travel in both directions, towards the origin and the insertion. The keeps the distribution of the Action Potential even so that the stimulation of corresponding muscle fibers is even allowing for maximum force in contraction of the entire muscle.
96
What is Botox?
Botox is actually poison derived from the bacterium clostridium botulism. Tilt has the effect of blocking the release of acetylcholine for the axon terminal. When ACh is not released the action potential is not generated and muscles do not contract. Large amounts of clostridium botulism leads to paralysis of the respiratory muscles and the heart. Death will occur.
97
How is it that cardiac muscle tissue is able to contract up to 10-15 time singer than skeletal muscle?
The high levels of calcium I cardiac muscles allow prolonged contraction.
98
What is autorhythmicity?
Autorhythmicity is a property of cardiac muscle, it contracts in response to its own self generated action potentials.
99
What is the SA node?
The SA node is the sino atrial node and is found in the upper half of the heart. (The atrium)
100
What is the AV node?
The AV. Ode is the atrial ventricular node and is found in the lower half of the heart. ( the ventricles)
101
What do the SA nodes and the AV nodes do?
The SA and the AV nodes are responsible for electrical signals of the heart. The electrical signals create the staggered automatic rhythmic contractions of the upper and lower portions of the heart.
102
What characteristic is unique to cardiac muscle?
Cardiac muscle has intercalated discs made up of gap junctions & desmosomes.
103
How does auto-rhythmicity occur in smooth-non striated muscle?
Auto-rhythmicity in smooth non-striated muscle occurs when a nervous signal sent from the autonomic nervous system sends an Action Potential to a muscle, it then is sent to all associated muscle fibers.
104
How are thin filaments attached in smooth non-striated muscle?
Thin filaments are attached to structures called dense bodies which are functionally similar to Z discs.
105
What are dense bodies?
Dense bodies are found in smooth non-striated muscle and are similar tomZ discs. Thin filaments attach to them.
106
Aside from thin filaments, what else attaches into dense bodies in smooth non-striated muscle?
Bundles of intermediate filaments attach to the dense bodies, they receive tension from the contracting sarcomeres of the muscle.
107
What are caveolae?
Caveolae are pouchlike invaginations that contain calcium within the smooth non-striated muscle.
108
What is calmodulin?
Calmodulin is a protein in smooth muscle proposed to bind calcium. It plays a role similar to troponin in skeletal muscles.
109
What are the 2 types of smooth muscle?
The 2 types of smooth muscle are visceral (single unit) and multi unit.
Visceral is more common, multi unit is less common.
110
Smooth muscle is very physiolocally,similar to skeletal muscle except for 2 things, what are the 2 things?
1. Physiologically, smooth muscle has much slower contractions, both onset and duration. It takes much longer for a contraction to initiate and the duration may last for hours.
2. Smooth muscle has the ability to stretch and distend to much greater lengths.
111
How many ways can muscles generate ATP?
3
112
What are the 3 ways that muscles generate ATP?
1. Creatine phosphate
2. Anaerobic metabolism
3. Aerobic metabolism
113
Where is creatine phosphate found?
Creatine phosphate is high in energy and found nelly in muscles.
114
Where is creatine phosphate produced?
Creatine phosphate is produced in the liver, kidneys & pancreas, then transferee to muscles for storage.
115
What is creatine kinase?
Creatine kinase (CK) is an enzyme that transfers a phosphate group from ATP to creatine making creatine phosphate. This reaction also reverses.
116
How long does creatine phosphate provide maximum muscle contraction for?
Creatine phosphate provides maximum muscle contraction for about 15 seconds, about long enough to run a 100 meter dash.
117
What is the by product of creatine metabolism?
The by product of creatine metabolism is creatinine, a metabolite excreted out with urine.
118
The creation of creatine phosphate + ADP is a reversible reaction.
ATP + creatine -> creatine phosphate + ADP -> ATP + creatine
