Muscular Tissue (L1 & C7) Flashcards
(84 cards)
1
Q
Name the 4 types of cells that can contract
A
Muscle cells/Fibers
Pericytes
Myoepithelial cells
Myofibroblasts
2
Q
Name the muscular tissues that are striated
A
Cardiac
Skeletal
3
Q
Name the muscular tissue that is not striated
A
Smooth
4
Q
Name the muscular tissues that are voluntary
A
Skeletal
5
Q
Name the muscular tissues that are involuntary
A
Smooth
Cardiac
6
Q
State the function of myofibroblasts
A
Secrete Collagen and contract
7
Q
State the structure and location of pericytes
A
Structure:
Smooth muscle-like
Location:
Surrounding blood vessels
8
Q
State the location of myoepithelial cells
A
Around certain glands
9
Q
State the other names for a muscle cell
A
Muscle fiber / Myofiber
10
Q
State the other name for a muscle cell’s cytoplasm
A
Sarcoplasm
11
Q
State the other name for smooth ER in a muscle cell
A
Sarcoplasmic reticulum
12
Q
State the other name for the cell membrane of the muscle cell
A
Sarcolemma
13
Q
What are the contents of the Sarcoplasm that allow the muscle to perform its function
A
Myofibrils
Myoglobin
Mitochondria
Sarcoplasmic reticulum
14
Q
State the structure of a skeletal muscle cell
A
Long thin cylinder
15
Q
State the contents of cell inclusions in a skeletal muscle
A
Myoglobin and glycogen
16
Q
State the structure and function of myoglobin
A
Structure:
Globular protein similar to haemoglobin
Contains iron atom
Function:
Store oxygen
17
Q
Myofibrils are made of
A
Overlapping Myofilaments - Actin and myosin
18
Q
What is the functional unit of a muscle
A
Sarcomere
19
Q
State the structure of a sarcomere
A
- The region between 2 successive Z lines
- Bisected by the M line
- Dark Central A Band with a pale area called H band
- 1/2 Light Peripheral I Band on each side
20
Q
What is the A band made of?
A
Overlapping Myosin (Thick) and actin (thin) myofilaments
21
Q
What is the H band made of?
A
Myosin myofilaments only
22
Q
What are the I bands made of?
A
Actin myofilaments only
23
Q
Why is the A band called so?
A
It is Anisotropic
24
Q
Why is the I band called so?
A
It is Isotropic
25
The arrangement of myofilaments in a sarcomere cross section is a central myosin molecule surrounded by actin molecules in a _____________ arrangement
1/ Pyramidal
2/ Diamond
3/ Pentagonal
4/ Hexagonal
Hexagonal
26
State the structure of Actin Molecules
* Thin (5nm)
* Made of F-protein
* F-protein is made of G-proteins
27
State the 2 proteins closely associated with Actin with their function
Troponin (T,C,I) and Tropomyosin
Function:
Responds to Ca2+ concentration in the sarcoplasm to allow or prevent cross-bridge formation
28
State the structure of Myosin Molecules
* Thick (15nm)
* Polarized
* 2 globular heads attached to a tail
* Heads contain ATPase
29
What is the function of ATPase in Myosin
Enables binding of myosin to actin for the power stroke
30
State the structure of T-Tubules
Invaginations of the sarcolemma
31
State the structure of a Triad
1 T-Tubule with a terminal cisterna of sarcoplasmic reticulum on each sides
32
How many Triads are in each sarcomere?
2
33
What happens to the sarcomere when it contracts
Z lines move toward M line
H band disappears
Sarcomere shortens and in turn myofibrils
34
State the different muscle accessory proteins
```
Titin
Nebulin
alpha-actinin
Tropomodulin
Dystrophin
```
35
State the function of Titin
* Large protein connecting M and Z lines to maintain sarcomere length.
* It’s elastic contributing to passive elasticity of muscle
36
State the function of Nebulin
Large protein spanning actin’s length to attach it to Z line
37
State the function of alpha-actinin
Attaches actin, titin and nebulin to Z line
38
State the function of Tropomodulin
Attaches to free end of actin to regulate its length
39
State the function of Dystrophin
Attaches to sarcolemma and cytoskeleton to maintain sarcomere during contraction
40
What is Myotonia and what are it’s causes?
Neuromuscular condition where muscle is slow to relax after voluntary contraction
Occurs due to exposure to cold
41
What is Myotonia Congenita?
Genetic condition causing muscle stiffness due to prolonged contractions
42
What is the structure that is nonfunctional in myotonic muscular dystrophy?
Voltage gated Cl- channels in the sarcolemma
43
How is myotonia congenita diagnosed and treated?
Diagnosis:
Muscle Biopsy
Electrodiagnosis
Genetic Testing
Treatment:
No permanent cure
Physiotherapy and rehabilitation improve muscle action
44
State the features of Red muscle fibers regarding
```
1/ Myoglobin and mitochondria content
2/ Blood supply
3/ Enzymes (ATPase and oxidative)
4/ ATP Generation Method
5/ Contraction Speed
6/ Fatigue
```
1/ Myoglobin and mitochondria content - High
2/ Blood supply - Extensive
3/ Enzymes
ATPase - Low
Oxidative - High
4/ ATP Generation Method - Oxidative phosphorylation
5/ Contraction Speed - Slow and repetitive
6/ Fatigue - Not easily fatigued
45
State the features of white muscle fibres regarding
```
1/ Myoglobin and mitochondria content
2/ Blood supply
3/ Enzymes (ATPase and oxidative)
4/ ATP Generation Method
5/ Contraction Speed
6/ Fatigue
```
```
1/ Myoglobin and mitochondria content - Low
2/ Blood supply - Low
3/ Enzymes
ATPase - High
Oxidative - Low
4/ ATP Generation Method - Anaerobic Glycolysis
5/ Contraction Speed - Fast
6/ Fatigued - Easily
```
46
State the features of Intermediate muscle fibers regarding
```
1/ Myoglobin and mitochondria content
2/ Blood supply
3/ Enzymes (ATPase and oxidative)
4/ ATP Generation Method
5/ Contraction Speed
6/ Fatigue
```
1/ Myoglobin and mitochondria content - Intermediate
2/ Blood supply - Intermediate
3/ Enzymes (ATPase and oxidative) - Intermediate
4/ ATP Generation Method - Both
5/ Contraction Speed - Fast
6/ Fatigue - Not easily
47
True or false
| All skeletal muscles contain all types of muscle Fibers
True
48
Marathon runners have predominance of __________ muscle fibers
Intermediate (Type IIA)
49
Red muscle fibers are also called
Type I
50
Intermediate muscle fibers are also called
Type IIA
51
White muscle fibers are also called
Type IIB
52
Weight lifters have predominance of ___________ muscle fibers
White (Type IIB)
53
Muscle composition is changed by
Training
54
Vessels and nerves enter muscles by
Neurovascular bundle
55
Which of the following is absent in the endomysium?
1/ Capillaries
2/ Nerve Endings
3/ Lymphatics
Lymphatics
56
Lymphatics are present in all connective tissue components of the muscle except
Endomysium
57
Presence of skeletal muscle inclusions in electronmicropgraphs is a feature of
Nemaline Rod myopathy
58
A symptom of Nemaline Rod myopathy is
Mild to severe muscle weakness
59
Nemaline Rod myopathy is caused by
Mutations of genes coding proteins of thin myofilaments
60
Patients with Nemaline Rod myopathy have predominance of Type ______ fibers
Type I (Red)
61
A common site of injury in muscles
Muscle-Tendon Junction
62
State the structure of Muscle-Tendon Junctions
Extensions of myofibrils with projections of adjacent tendon
63
Single unaccustomed muscle exercise causes
Delayed onset muscle soreness
64
What are the symptoms of delayed muscle onset soreness?
Stiffness, pain and soreness
65
Where does delayed muscle onset soreness begin
Muscle-Tendon Junction
66
What are the causes of the symptoms of delayed muscle onset soreness
* Sarcolemmal Tear
* Cytoskeleton disarray
* Myofilament disruption
* Z Band streaming
* Acute Inflammation of endomysium causing stimulation of pain receptors (nocireceptors)
67
State the function Myo-satellite cells
* Reserving Stem cells
* Resting myoblasts
* Repair and regeneration of muscles
68
Myo-satellite cells are predominant in which type of muscles?
Slow twitch
69
Dense CT surrounding the entire muscle is called?
Epimysium
70
Septa that extend from the Epimysium to divide a muscle into fascicles is called?
Perimysium
71
Loose CT surrounding a single muscle fiber is called?
Endomysium
72
Muscle fibers and satellite cells are surrounded by
Basal Lamina
73
The external lamina of a muscle is made of
Reticular fibres and glycoproteins
74
Capillaries supplying muscles run along which axis of the muscle?
Longitudinal
75
What is the cause of Duchenne muscle dystrophy?
Mutation in gene on short arm of X chromosome.
| This gene codes for the protein dystrophin
76
What are the symptoms of Duchenne muscle dystrophy?
Progressive wasting and weakness of muscles
| Progressive Heart weakness
77
Duchenne muscle dystrophy is more common in which gender?
Males
78
The functional unit of a muscle is
Sarcomere
79
Muscle fibers have pleomorphic ____________
Mitochondria
80
The site of excitation-contraction coupling in a sarcomere is
Triad
81
State the location of T tubules
Junctions of A and I bands
82
State the function of T-tubules
Conduct electrical impulse from the sarcolemma to deeper part of the muscle fiber
83
State the location of Triads
Junction of A-I band
84
State the function of Triads
Regulate Ca2+ concentration in sarcoplasm by releasing or sequestering it
