Brainscape's Knowledge GenomeTM

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


See full index

NMSK > Muscle Structure > Flashcards

Muscle Structure Flashcards

1
Q

What is the typical vasculature of a muscle like?

A

Sometimes a single artery enters the muscle belly
Sometimes two or more arteries will enter and join up
Intramuscular arteries expand into capillaries

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

What is the typical vascularature of a muscle

A

Some have just one artery running into muscle belly
Some have more than one artery and they meet up
Intramuscular arteries expand into capillaries

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

What is an anastomosis?

A

surgical connection between two structures. It usually means a connection that is created between tubular structures, such as blood vessels or loops of intestine.

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

What is the inervature of the muscle like/

A

Single nerve branches out into connective tissue
Have motor neurons and sensory neurons
Has neuromuscular junctions

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

What are synergists/

A

Muscles that don’t facilitate or oppose a movement, but may effect it

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

What are fixators?

A

Muscles that stabilise a joint but doesn’t move it

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

What is the orgiin

A

Most proximal POA

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

What is the insertion?

A

Most distal POA

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

Where are skeletal muscles located?

A

Trachea, arteries

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

What are the 4 functions of skeletal muscle?

A

Locomotion and breathing
Posture and support
Heat production during cold stress
Largest protein store in the body

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

What is the structure of skeletal muscles like

A

Striated
Synctium (multinucleated)
Peripheral nuclei (at edge)

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

What are fasicles?

A

Bundles of muscle fibres

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

How big is each muscle fibre/

A

10-100 um in diameter
Up to 30cm in length

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

What is the epimysium

A

Surrounds whole muscle

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

What is the perimysium>

A

Surrounds bundles of muscle fibres (fascicles)

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

What is the endomysium

A

Surrounds individual muscle fibres

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

What is the sarcolemma?

A

Muscle cell membrane

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

What are Myofibrils

A

Myofibrils are long filaments that run parallel to each other to form muscle (myo) fibers. The myofibrils, and resulting myofibers, may be several centimeters in length. The muscle fibers are single multinucleated cells that combine to form the muscle. Myofibrils are made up of repeating subunits called sarcomere
Tubular structures that pack the fibres

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

What are myofilamwnts?

A

Threadlike strands within the myofibrils
Actin and myosin

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

What is the I band?

A

Actin alone

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

What is the A band

A

Myosin and actin (ambos)

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

What is Z lime?

A

End of sarcomere
Defines boundaries

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

What is H zone

A

Myosin only

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

How do muscles contract?

A

Calcium binds to troponin
Causes tropomyosim to change shape and move away from myosin binding site on actin
Cross bridge bwteeen actin and myosin forms
ATP —> ADP + P breaks cross bridge

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

What are the three different types of fast fibres

A

Type IIa
Type IIb
Type 11x

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

How can you distinguish between different muscle fibre types

A

Each fibre type has a specific immunohistochemistry
Specific histochemistfy (ATPase activity)
Specific metabolic profiles

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

What is the following like for type I fibres? (Slow oxidative)
Size of motor unit
Itodhondira
Fatigue resistant
Speed of contraction
Typical functions

A

Small
Many
High
Low
Posture

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

What is the following like for type IIa fibres? (Fast oxidative)
Size of motor unit
Itodhondira
Fatigue resistant
Speed of contraction
Typical functions

A

Intermediate
Many
Intermediate
Moderate
Walk, run

29
Q

What is the following like for type IIx fibres? (Fast glycolytoc fibres)
Size of motor unit
Itodhondira
Fatigue resistant
Speed of contraction
Typical functions

A

Large
Moderate
Low
High
Jump, throw

30
Q

What is the following like for type II b fibres? (Very fast glycolytic fibres)
Size of motor unit
Itodhondira
Fatigue resistant
Speed of contraction
Typical functions

A

Very large
Few
Very low
Very high
Jump, throw

31
Q

What is muscle fatigue and what are the causes of it?

A

Decrease in maximum contractile force

No ATP for formation of cross bridges
Increase in inorganic phosphate
Decrease in Ca2+

32
Q

What is a motor unit?

A

Single motor neuron and all of the muscle fibres it innervates
All fibres innervated simulataneously
All same fibre type

33
Q

How does the neuromuscular junction work?

A

Action potential at end of neuron stimulates Ca2+ channels to open
Ca2+ channels open and causes vesicles carrying acetylcholine to move to membrane
Acetylcholine moves across synapse and binds to Na+ channels
Na+ enters in membrane of muscle

34
Q

What breaks down acetylcholine

A

Acetylcholinesterase

35
Q

What will happen if drugs act at Ach receptor

A

Muscle will stay relaxed

36
Q

What do antiacetylcholineestersse drugs do

A

Prevent breakdown of acetylcholine so more activation of muscle

37
Q

What do t tubules do?

A

Help spread single from motor neuron throughout muscle

38
Q

What channel does sarcoplasmic reticulum contain?

A

Ryanodine receptor for Ca2+

39
Q

How do t tubules help muscle contraction

A

Action potential in t tubules
Opens Ca2+ in sarcoplasmic reticulum
Ca2+ releases indices more Ca2+ to be released
Them Ca2+ pumped back into SR

40
Q

What are the two types of receptors in muscles/

A

Muscle spindles
Golgi tendon organ

41
Q

What are muscle spindle fibres

A

Provide information on length of muscle and how quickly it is changing (velocity)
Sensory neurons in fibres to detect this
Uensitive to stretch

42
Q

What are Golgi tendon organs?

A

Monitor tension developed in muscle
Prevents damage during excessive force generation

43
Q

What is an aponeurosis

A

A flat sheet of muscle with flat tendons

44
Q

What is the structure of a smooth muscle like?

A

Single centrally located nucleus
No striations

45
Q

Where would you find smooth muscle

A

In viscera (internal organs)
Blood vessels
Uterus wall

46
Q

What controls each type of muscle

A

Skeletal- somatic
Cardiac/ smooth- autonomic

47
Q

What can stimulate smooth muscle to contract

A

Hormones
Neuronal communication

48
Q

What is the structure of skeletal muscle like?

A

40cm in length
100um in diameter
Multinucleated at periphery
Striations

49
Q

What are the two types of skeletal muscles

A

Slow twitch
Fast twitch

50
Q

What is the structure of cardiac muscle like?

A

Up to 90um in length
Up to 15um in diameter
One or two nuclei in centre of cell
Show striations
Cardiomyocytes are often branched for cell to cell connectiin

51
Q

What happens to muscle structure is immobilised?

A

Sarcomeres deleted

52
Q

What is hypertrophy and hyperplasia?

A

Hypertrophy- cells increasing in size
Hyperplasia- increasing number of cells

53
Q

How do muscles grow?

A

Due to hypertrophy
Muscle fibre increases in size, increase in myofibrils and myofilaments

54
Q

What factors can cause hypertrophy in muscles?

A

Building up the muscle
Anabolic steroids

55
Q

What factors cause atrophy (breakdown of muscles)

A

Disuse
Denervation
Disease
Malnutrition

56
Q

How does a mechanical stimukus increase muscle size?

A

IGF 1 causes:
satellite cell profilerstiom
Protein synthesis (myosin and actin)

57
Q

What is the problem with IGF 1?

A

Cause cause too much cell proliferation, so results in tumour production

58
Q

Why does necrosis of muscle cells occur?

A

Torn/ damaged sarcolemma
Influx of Ca2+, which triggers necrotic mechanisms

59
Q

What is the function of satellite cells and where are they?

A

Activated following damage
Profilerste and differentiate to form muscle cells and daughter cells
In between sarcolemma and endomysium

60
Q

What is stringhalt?

A

Onset of excessive Flexion in one or both hind limbs
Causes severe muscle spasms (tetanises)
Muscle atrophy
Most likely by nerve damage, and muscles stay fully contracted

61
Q

What is neuropathy of the laryngeal muscles?

A

Only affects left muscles, as left recurrent laryngeal nerve goes round aorta so more likely to get damaged
Affects ability to open glottis (opens into windpipe)
Turbulent air flow, so causes roaring

62
Q

How can you detect muscle damage?

A

Myoglobinuria —>check urine for myoglobin (like heamoglobin in muscle, binds to O2), too much can indicate muscle damage and could cause kidney damage

Creatine kinase —> enzyme used by muscles, but not specific. Increase levels can indicate muscle damage or wasted

63
Q

What is polymyosistois?

A

Generalised inflammatory myopathy
Due to over active immune response, from cell mediated

64
Q

What is masticating muscle myositis?

A

Focal inflammatory myopathy, only affects muscles in jaw for chewing
Lock jaw
Prominence of zygomatic arch (cheekbone)

65
Q

What is Duchenne Muscular dystrophy?

A

Congenital/ inherited myopathy
Occurs in dog, humans and mice
Mutation in the gene coding for membrane protein dystrophin
Links to degeneration of respiratory muscles

66
Q

What are the two examples of endocrine myopathies

A

Hypothyroidism —> stiffness, weakness, muscle wastage, atrophy of type II fibres

Cushing disease —> muscle weakness, stiff gait, muscle atrophy and inability to walk in dogs. Atrophy of type II Fibres, inhibition of muscle protein synthesis

67
Q

What is selenium/ vitamin D deficiency

A

Still birth/ weak calf
Doesn’t usually affect carnivores

68
Q

What is sarcopenia

A

Atrophy associated with ageing
Due to loss of motor neurons
Degeneration
Loss of motor fibres
Fibrosis—> build up of connective tissue

NMSK (47 decks)

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