Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

RRPA Pathophysiology II > Muscle Tissue - Mace: exam 2 > Flashcards

Muscle Tissue - Mace: exam 2 Flashcards

1
Q

What type of muscle has striations?

A

Skeletal muscle and cardiac muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What type of muscle is unbranched?

A

Skeletal and smooth muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What type of muscle is multinucleated?

A

Mostly skeletal muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What type of muscle has intercalated discs?

A

Cardiac muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the function of intercalated discs?

A

Allows for functional syncytium(allows for low resistance ion movement)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What types of muscle is unbranched?

A

Skeletal muscle and smooth muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

In what type of muscle cells is the nucleus pushed to the side of the cell?

A

Skeletal muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Order the following from innermost to outermost. Perimysium Endomysium Epimysium

A

Endomysium Perimysium Epimysium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the functions of skeletal muscle?

A

Body movement Maintenance of posture Protection and support Storage and support Heat production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is a fasicle?

A

A bundle of muscle cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What type of connective tissue are the following tissues composed of? Epimysium Perimysium Endomysium

A

Epimysium- dense irregular CT Perimysium- Dense irregular CT Endomysium - Areolar CT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Tendon is composed of what type of CT?

A

Dense regular CT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Individual muscle cells are separated by _____.

A

Endomysium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is a fascicle?

A

A bundle of muscle cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Fascicles are separated by ______.

A

Perimysium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Intercalated discs are composed of _____ and ________.

A

Desmosomes and gap junctions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Gap junctions allow for what important function?

A

Allows for ion movement between cells, allowing the heart to work as a functional syncytium.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the primary function of desmosomes?

A

Holding cells together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What types of muscle are under involuntary control?

A

smooth and cardiac muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Tendons are composed of what type of CT?

A

Dense regular CT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

A thin flattened sheet of tendon with a wide area of attachment is called a _______.

A

Aponeurosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Tendons and aponeuroses are made of how many layers of connective tissue?

A

3 - the endomysium, perimysium, and epimysium continue into tendons.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Deep fascia is made of what type of connective tissue?

A

Dense irregular CT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the difference between hypertrophy and hyperplasia?

A

Hypertrophy is an increase in the size of individual cells. Hyperplasia is an increase in the number of cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Does weight lifting cause hypertrophy or hyperplasia?

A

Hypertrophy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Do skeletal muscle cells have one nucleus or multiple?

A

Multiple

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the function of satellite cells in skeletal muscle?

A

Differentiate for repairing injured muscle cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the sarcolemma?

A

Muscle cell membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What are T-tubules?

A

Deep invaginations of the sarcolemma for transmitting nerve impulses from the sarcolemma inwards

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What are terminal cisternae?

A

Dilations ends of sarcoplasmic reticulum that serves as a reservoir for calcium ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is a triad in a muscle cell?

A

T tubule with terminal cisternae on the sides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is the sarcoplasmic reticulum?

A

A tubular network surrounding contractile proteins made of modified smooth endoplasmic reticulum.

33
Q

Functions of myoglobin?

A

Allows muscle cell to store oxygen

34
Q

What are myofibrils?

A

contractile proteins, composed of thin and thick myofilaments.

35
Q

Myofibrils occupy what percentage of total cell volume?

A

80%

36
Q

Thick filaments are composed of what?

A

Myosin - a protein with a globular head and elongated tail

37
Q

Thin filaments are composed of what?

A

G (globular) actin and F (filamentous) actin.

Tropomyosin

Troponin

38
Q

Explain the arrangement of molecules in the thin filaments.

A

G actin with F actin spiraling around it. Tropomyosin is bound to F actin and troponin is bound to tropomyosin.

39
Q

What happens to thin filaments when Ca++ binds to troponin?

A

Binding of troponin causes conformational shift in tropomyosin which exposes the myosin binding sites on F actin.

40
Q

What is the functional unit of muscle?

A

The sarcomere

41
Q

What separates sarcomeres?

A

Z discs

42
Q

Define the following terms: I band A band H zone M line

A
  • I band - Region containing only thin filaments
  • A band - central region of sarcomere, contains entire thick filament and partially overlapping thin filaments
  • H zone - Central portion of A band containing only thick filaments
  • M line - Protein meshwork structure at center of H zone
43
Q

What color are I bands and A bands under a microscope?

A

I bands are light A bands are dark

44
Q

T/F? Each muscle cell has only one neuromuscular junction

A

True

45
Q

Neuromuscular junctions are composed of what structures?

A

Synaptic knob, motor end plate, synaptic cleft

46
Q

Explain how the synaptic knob functions up to the point of ACh release.

A

Nerve signal causes voltage gated calcium channels to open. Calcium enters synaptic knob and binds to synaptic vesicles, which leads to exocytosis of synaptic vesicles containing ACh

47
Q

The synaptic cleft contains what enzyme? What is its function?

A

Acetylcholinesterase Breaks down ACh molecules after they’re released into synaptic cleft

48
Q

How does the binding of ACh by the motor end plate start an action potential?

A

Binding of ACh opens Na+/K+ channels on the motor end plate, creating an end plate potential (EPP). EPP triggers action potential which propagates along sarcolemma and T tubules. Action potential causes opening of Ca2+ channels leading to cross bridge cycling.

49
Q

Cross bridge cycling is responsible for the contraction of the muscle. Explain how it works.

A

Ca++ enters muscle cells, and binds to troponin. This causes conformational shift of tropomyosin and myosin binding sites become exposed. With myosin binding sites exposed, myosin heads on thick filaments bind to the thin filaments. Myosin heads swivel and causing thin filaments to be pulled past thick filaments. Myosin heads bind ATP and release from thin filaments ATPase breaks ATP down into ADP and Pi, which provides the energy to reset the myosin heads.

50
Q

Why aren’t H bands present on microscopy when muscle is contracted?

A

Thin and thick filaments are overlapping so H band is not visible.

51
Q

Explain the process of skeletal muscle relaxation.

A

AChesterase hydrolyzes ACh in synaptic cleft. Without ACh, no further action potential is generated. Ca++ channels close and Ca++ is pumped back into SR. Without Ca++ in cells, tropomyosin returns to its position covering myosin binding sites.

52
Q

Dantrolene is a drug that causes decrease in muscle spasticity. How does it work?

A

Interferes with release of Ca++ from SR.

53
Q

Succinylcholine is a drug used for surgery and intubation because it causes flaccid skeletal muscle paralysis. How does it work?

A

The drug binds to ACh receptors, but does not produce the effect of ACh, preventing the muscle from generating an action potential. AChesterase cannot break down the drug.

54
Q

In what ways can muscles produce ATP in order to work?

A

Phosphagen system Glycolysis Oxidative phosphorylation

55
Q

Rank the following from fastest to slowest in terms of energy production. Phosphagen system Glycolysis Oxidative phosphorylation

A

Phosphagen system - 5-6 seconds Glycolysis - 50-60 seconds Oxidative phosphorylation 5-6 minutes

56
Q

Which modes of skeletal muscle metabolism are anaerobic? Aerobic?

A

Phosphagen system - anaerobic Glycolysis - anaerobic Oxidative phosphorylation - aerobic

57
Q

Which mode of skeletal muscle metabolism is most efficient?

A

Oxidative phosphorylation

58
Q

Power of muscle contraction is determined by what factor?

A

Muscle fiber diameter

59
Q

Speed of muscle contraction is determined by what factor?

A

Slow or fast twitch muscle fibers

60
Q

Fast twitch muscle fibers use what type of metabolism?

A

Anaerobic (phosphagen system or gylcolysis)

61
Q

How many ATP are produced per glucose in glycolysis vs oxidative phosphorylation?

A

Glycolysis - 2 ATP per glucose Oxidative phosphorylation - 34 ATP per glucose

62
Q

What type of metabolism would you expect slow twitch muscle fibers to use?

A

Oxidative phosphorylation

63
Q

What type of muscles do you expect to be well vascularized? Why?

A

Slow twitch because they use aerobic metabolism so they need a good supply of oxygen from the blood

64
Q

What type of muscle is the most red in color? Why?

A

Slow twitch because it has higher concentration of myoglobin because myoglobin is used to store oxygen

65
Q

What is isometric contraction?

A

Muscle contracts and shortens, but the angle of the joint does not change.

66
Q

What is isotonic contraction?

A

Muscle contracts and shortens overcoming the load, joint angle changes

67
Q

What are the two types of isotonic contraction? Describe them.

A

Concentric - isotonic contraction with the muscle length decreasing Eccentric - isotonic contraction with the muscle length increasing

68
Q

Define a muscle twitch

A

Single brief contraction in response to a single stimulation

69
Q

Define threshold.

A

Minimum voltage needed to active a muscle

70
Q

Define the latent peroid

A

Time after stimulus is applied before contraction begins

71
Q

What is the mechanism of tetany?

A

Increased frequency of stimulation to muscles causes contraction

72
Q

What is the mechanism of rigor?

A

Lack of ATP, so myosin heads cannot reset to relaxed postion

73
Q

In what ways is cardiac muscle similar to skeletal muscle?

A

Striations, t-tubules, and CICR

74
Q

Is cardiac muscle metabolism aerobic or anaerobic?

A

Almost entirely aerobic

75
Q

What muscle cells would you expect to see a high volume of mitochondria?

A

Cardiac muscle

76
Q

T/F? Smooth muscle does not have sarcomeres?

A

True

77
Q

Describe the anchoring proteins of smooth muscle.

A

Smooth muscle has a cytoskeleton made of intermediate filaments. Dense bodies bind the filaments into the sarcoplasm, and dense plaques to the SL

78
Q

Thick filaments of smooth muscle have a latch mechanism. What benefit does this provide?

A

Allows muscle to stay contracted without using additional ATP

79
Q

Explain the pathway of smooth muscle contraction starting when calcium enters the cell.

A

Calcium binds to calmodulin forming Ca++ calmodulin complex. Ca++ calmodulin complex activates MLCK MLCK activates myosin Activated myosin can form cross bridges to contract.

RRPA Pathophysiology II (16 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions