Brainscape's Knowledge GenomeTM

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


See full index

Locomotor 2 > Muscles in Health and Disease > Flashcards

Muscles in Health and Disease Flashcards

1
Q

What is muscle important for

A
  • Store for intracellular ions such as potassium and small amounts of calcium in the dissolved water
  • Important for heat production
  • Glucose handling
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How much body weight and store of water is muscle

A

40% of body mass

80% of water

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

what are the different types of muscle

A

skeletal muscle/stirated
cardiac muscle
smooth muscle

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

what is sacromere made up of

A

actin and myosin

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

describe skeletal muscle

A
  • stripy appearance

- nuclei in the periphery

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

in skeletal muscle what is central nuclei are marker of

A

muscle regrowth - new muscle formation

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

describe the nerve supply to the skeletal muscle

A

LMN – ventral horn of the spinal cord, exit from the ventral root, enter from the peripheral nerves, motor neurone then spreads out to innervated 5 and up to 100 or more muscle fibres

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

what happens when you lose a single motor neurone innervation

A

Affects all muscle fibres innervated by that motor neurone

  • in about 2 months the muscles will atrophy
  • Small angulated muscle fibres
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is a motor unit

A

all muscles fibres innervated by that Motor neurone

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

if only one single motor neurone looses its innervation what can other neurones od

A

Sprouting of remaining motorneuron axons synapse with denervated fibres.

Motor units enlarge and rather than been scattered they appear as groups.

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

What is fibre type determined by

A

Fibre type determined by primary motor neuron

- motor unit fibres all same fibre time

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

describe what happens in motor neurone disease

A
  • In conditions where you have continuous loss of motor neurons it comes to the point where more of the motor neuornes have died and the remaining motor neurone have tried to asses the muscle fibres that are being innervated and the motor unit is larger

If that motor nuerone then dies then a lot of muscles loose innervation

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

what is infant hypotonia

A
  • infants muscles are hypotonic

- get a floppy hypotonic baby

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

what can cause infantile hypotonia

A
  • myopathic reason

- most of the fibres are small with a few massive hypertrophic fibres

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

What are the two types of infantile hypotonia

A
  • Large type 1 muscle fibres (paler) = Slow type 1 fibres aerobic metabolism mainly
  • Small type 2 muscle fibres (darker) = Fast type 2 fibres mixed aerobic and anaerobic metabolism
  • Small fibres = type 1 fibres = Slow type 1 fibres aerobic metabolism mainly
  • Type 2 fibres are normal to larger in diameter. = Fast type 2 fibres mixed aerobic and anaerobic metabolism
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is the good thing about infantile hypotonia

A
  • usually sort itself out but no lasting problems

- but may not be able to do lots of exercise as they may fatigue more easily

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

What are the two types of skeletal muscle

A

Slow type 1 fibres aerobic metabolism mainly

Fast type 2 fibres mixed aerobic and anaerobic metabolism

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

What is sarcopenia

A

the loss of skeletal muscle mass and strength as a result of ageing.

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

How much skeletal muscle mass is lost after the age of 50 years

A
  1. 5 – 1% loss after age of 50 years

- But up to 3% - 5% if physically inactive

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

what happens to bone mass and muscle mass with ageing

A
  • loss muscle mass = sarcopenia
  • loose bone mass = osteoporosis
  • muscle strengths is lost therefore impaired balance
  • decreased bone strength
  • these things contribute to fracture
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are general symptoms of muscle disorders

A 
Pain and weakness
Twitching and cramps
Muscle atrophy and contractures
Family history
Drug exposure
Endocrine disorders
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How do you diagnose muscle disorders

A

Biopsy

EMG - electromyography

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

What are the two inflammatory myopathies and what is the difference

A

Polymyositis

Dermatomyositis (only difference is with this one you get a skin rash)

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

where do inflammatory myopathies start

A

Starts at the periphery of the muscle fascile

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

describe the characteristics of inflammatory myopathies

A

Associated with microbial infection

Autoimmune

Proximal muscle weakness (around shoulder and around the hip)

5-10 million per year

2:1 prevalence in females

40-60 years

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

what are the clinical features of inflammatory myopathies

A

Symmetrical involvement of large proximal muscles of shoulders, arms and thigh

27
Q

how do you diagnose inflammatory myopathies

A

Serum creatine kinase elevated = marker of muscle damage

EMG
- typical irritability in 90%

Biopsy most definitive

  • Variation in fibre size
  • Central nuclei
  • Necrosis and regeneration
  • Infiltrate of inflammatory cells (lymphocytes)
28
Q

What is found in the biopsy in inflammatory myopathies

A

Lymphocytes surround and invade individual muscle fibres (CD8+ T lymphocytes) with some macrophages to remove necrotic fibres

  • damaged muscle fibres
  • centrally located nuclei where there is regeneration
29
Q

What does the Dermatomyositis rash look like

A

Dermatomyositis rash is typically purplish in colour and often
has a streaky pattern. Heliotrope
rash over eyelids with oedema

30
Q

in inflammatory myopathies what antibody is found positive

A

ANA positive in 90% of cases

- anti-Jo1 antibody (20-40% of cases)

31
Q

what is subcutaneous calcifications

A

Autoimmune connective tissue disease

Calcification in muscles and in skin

32
Q

what is the treatment of inflammatory myopathies

A

Corticosteriods

  • High dose 1mg/kg prednisone per day
  • Maintained until creatine kinase normal
  • If stopped early flares in disease and difficult to control
  • Azathioprine
  • Methotrexate
33
Q

what is the survival rate for inflammatory myopathies

A

5 year survival = 80%

8 year survival = 73%

Death from malignancy, infection and pulmonary involvement

More likely if anti-Jo 1 positive

34
Q

what is inclusion body myositis

A
  • most common muscle disease of the elderly
  • poor prognosis
  • loss of specific muscle groups
35
Q

what is the must common muscle disease of the elderly

A

inclusion body myositis

36
Q

what is inclusion body myositis more common in

A

males

37
Q

what is elevated in inclusion body myositis

A

Mild elevation in creatine kinase

38
Q

what muscles are affected by inclusion body myositis

A

Finger and wrist flexors more than extensors and shoulder abductors

Knee extensors more than hip flexors

39
Q

what problems are associated with inclusion body myositis

A

Associated polyneuropathy

Loss of quadriceps reflex

Dysphagia

40
Q

what does the biopsy of inclusion body myositis

A

Fibres contain empty vacuoles and clumps
of cellular material
that contain amyloid
like material (congo red).

Filamentous inclusions of IBM
have optical properties of amyloid and contain beta amyloid, hyperphosphorylated
tau, apolipoprotein E,
presenillin 1, prion protein,
and other proteins that accumulate in muscle

41
Q

give example of x linked muscular dystrophies

A

Duchenne and Becker muscular dystrophies

Limb girdle muscular dystrophy

Emery-Dreifuss muscular dystrophy

42
Q

What are muscular dystrophies

A

Progressive genetically linked degenerative myopathies
- Effecting the cytoskeletal proteins that maintain the integrity of the muscle membrane and the connection with the extracellular matrix outside the cell

43
Q

name some autosomal recessive muscular dystrophies

A

Limb girdle muscular dystrophy

Emery-Dreifuss muscular dystrophy

44
Q

name some autosomal dominant muscular dystrophies

A

Facioscapulohumeral muscular dystrophy

Limb girdle muscular dystrophy

Emery-Dreifuss muscular dystrophy

Oculopharyngeal muscular dystrophy

45
Q

name the muscle areas that are affected by

  • Duchenne and Becker
  • Limb Girdle
  • Facto-scapulo humeral
  • emery- Dreifuss
A

Duchenne and Becker

  • arm
  • plantar flexors
  • thigh

Limb Girdle

  • thigh
  • shoulder region

Facto-scapulo humeral

  • face
  • shouter region
  • plantar flexors

emery- Dreifuss

  • shoulder and arm
  • plantar flexors
46
Q

What is the most common muscular dystrophy

A
  • Duchenne muscular dystrophy is the most common
47
Q

what happens in Duchenne muscular dystrophy

A

It is the completely loos of dysphotrin protein,

Usually connects the contractile apparatus to the ECM and maintains the integrity of the muscle membrane

48
Q

How many people get Duchenne muscular dystrophy

A

20-30 per 100,000 males per year (1:3,500 male babies)

49
Q

what muscles are affected by Duchenne muscular dystrophy

A

Proximal muscle weakness during first 2 years

50
Q

describe duchen muscular dystrophy and its progression

A

Continuous slow decline

  • Unable to walk by 7-12 years
  • Death usually mid twenties to early thirties
  • heart is affected therefore they often die from cardiomyopathy
51
Q

What happens to creatine kinase in Duchenne muscular dystrophy

A

severely elevated

52
Q

describe the biopsy of Duchenne muscular dystrophy

A
  • Fibre size variability
  • Endomysial fibrosis
  • Degenerating muscle fibres undergoing myophagocytosis
  • repeated degeneration and regeneration of muscle fibres therefore you end up depleting the muscle stem cells
  • eventually you loose the muscle fibres and replace it with fibrotic or fat
53
Q

what is Beckers disease

A
  • Dysphotrin protein is shortened and is not as good as protecting the muscle membrane but still works
  • Therefore it is milder
54
Q

What is the treatment for Duchenne muscular dystrophy

A
  • corticosteroids
55
Q

what can corticosteroids induce

A

Type 2 fibre atrophy

  • Has implications on person being able to move
  • Type 1 is for posture whereas type 2 is for movement and generating force- has influence of ability of individual to move
  • Take them off corticosteroids and this fibre goes back to its original size therefore the atrophy is not permanent
56
Q

what can stains lead to

A

Approx 10% of patients

Rhabdomyolysis - myoglobin clogs the kidneys and can cause potential renal filature

57
Q

how can alcohol damage the muscle

A
  • have muscle atrophy
  • Chronic - slow progressive proximal weakness
  • Acute - single heavy session
58
Q

What is fibromyalgia

A
  • connective tissue disorder

- Widespread muscle pain

59
Q

describe fibromyalgia diagnostic criteria

A

Both sides of the body, above and below waist, in axial skeleton

Combination of 11 or more of 18 specific tender points - 2kg of pressure applied

60
Q

what is the trigger of fibromyalgia

A

Antipolymer antibodies

- 50% of patients positive

61
Q

what is fibromyalgia associated with

A

Associated fatigue and sleep disturbance

30-60 year age group

80-90% patients female

62
Q

describe the cycle of fibromyalgia

A

Muscle tension from daily stress leads to fatigue muscle stiffness and pain
Pain leads to poor quality of sleep
Sleep increases the stress levels and you ability to be able to cope with stress so you feel more pain and this leads round

63
Q

what is the treatment of fibromyalgia

A

Tricyclic antidepressants
- amitriptyline

SSRIs
- fluoxetine

Exercise

Complementary therapy

Locomotor 2 (30 decks)

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