Physiology Flashcards

1
Q

How do muscles produce movement?

A

Through contraction

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

Cardiac muscle

A

Striated

Involuntary - regulated by ANS

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

Smooth muscle

A

Non-striated

Involuntary - regulated by ANS

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

Skeletal muscle

A

Striated
Voluntary - regulated by somatic nervous system
Multi-nucleated (nuclei at periphery)
Needs nervous stimulation to initiate contraction
Motor units present

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

What is the transmitter of the neuromuscular junction?

A

ACh

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

What is a motor unit?

A

Single alpha motor neurone which innervates many muscle fibres.
The number of muscle fibres per motor unit varies depending on the functions of the muscle

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

Muscles which serve fine movements (facial expression, intrinsic hand muscles) have LOTS/FEW fibres per motor unit?

A

Few

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

When power (e.g. thigh muscles) is more important than precision, there are LOTS/FEW fibres per motor unit?

A

Lots

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

Skeletal muscle organisation

A

Muscle fibres are held together by loose connective tissue.

Each muscle fibre = 1 muscle cell

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

Contractile units within muscle fibres?

A
Myofibrils 
contain actin (thin, light) and myosin (thick, dark) filaments
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Functional units of skeletal muscles?

And where are they found?

A

Sarcomeres

Found between 2 Z-Z lines

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

Z lines

A

Connect the thin filaments of 2 joining sarcomeres

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

A band

A

Made up of thick filaments

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

H zone

A

Lighter area in the middle of A band

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

M line

A

Extends vertically down the middle of an A band

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

I band

A

Remaining portion of thin filaments

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

How do muscles contract?

A

Sliding of actin filaments on myosin filaments.

ATP and calcium are needed

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

Cross bridge formation - muscle contraction

A

Calcium binds to troponin causing a conformational change.

This exposes the actin and myosin binding site so cross bridging occurs

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

Muscle relaxation

A

Calcium unbinds from Troponin and cross bridges between actin and myosin break.
ATP is required

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

If the muscle is stimulated continuously, it produces a STRONGER/WEAKER contraction

A

Stronger

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

Skeletal muscle action potential

A

The tension increases with increasing frequency of stimulation.
(if a skeletal muscle is stimulated once, a single twitch is produced. but if a skeletal muscle receives a second stimulation before it has time to completely relax, then greater muscle tension is developed.

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

What is tetanus?

A

A sustained contraction which occurs if a skeletal muscle is stimulated rapidly and it doesn’t have an opportunity to relax

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

Skeletal muscle optimum length

A

Resting length

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

Isotonic contraction of skeletal muscle

A

Length of muscle changes
Muscle tension remains constant
eg: body movements

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

Isometric contraction of skeletal muscle

A

Length of muscle constant
Muscle tension changes
eg: maintaining body posture

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

ATP production in skeletal muscle fibres

A

Transfer of high energy phosphate from creatinine phosphate to ADP (immediate source of ATP)

Oxidative phosphorylation produces an abundance of ATP (when O2 present)

Gycolysis produces ATP (when O2 absent)

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

Slow oxidative skeletal muscle fibres (type 1)

A

Low myosin ATPase activity, so contraction is slow
Lots of mitochondria -> lots of oxidative phosphorylation
Used for prolonged relatively low work aerobic activities (e.g.: walking)

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

Fast glycolytic muscle fibres (type IIb)

A

High myosin ATPase activity, so contraction is fast
Few mitochondria -> rely on glycolysis to get ATP
Mainly used for short term high intensity activities (jumping)

29
Q

Fast oxidative skeletal muscle fibres (type IIa)

A

Mixture of type I and type IIb.
High myosin ATPase activity, contraction is fast
Lots of mitochondria -> lots of oxidative phosphorylation
Use aerobic and anaerobic metabolism
Mainly used for prolonged activity (e.g. jogging)

30
Q

Function of synovial fluid

A

Lubricates joint - minimises wear and tear
Facilitates joint movement by reducing friction
Supplies chondrocytes with oxygen and nutrients

31
Q

Rapid movement causes an INCREASE/DECREASE in synovial fluid viscosity?

A

Decrease

32
Q

Rapid movement causes an INCREASE/DECREASE in synovial fluid elasticity?

A

Increase

33
Q

Gross appearance of normal synovial fluid

A

Clear, colourless

34
Q

Gross appearance of trauma related synovial fluid

A

Red

35
Q

Gross appearance of mildly synovial inflammation

A

Slightly yellow

36
Q

Gross appearance of severe synovial inflammation

A

Opaque, cloudy

37
Q

What is cartilage?

A

Semi-rigid, deformable, permeable

No blood supply

38
Q

Hyaline (articular) cartilage - where is it found?

A

Tracheal rings, costal cartilages, epiphyseal growth plate during development

39
Q

Hyaline (articular) cartilage - function?

A

Covers articular surfaces of bones
Prevents wear and tear
Distributes pressure

40
Q

Hyaline (articular) cartilage - composition?

A

Elastic

Sponge-like properties

41
Q

Elastic cartilage - where is it found?

A

Ears

42
Q

Elastic cartilage - function?

A

Flexible

Bounces back into shape

43
Q

Cartilage components

A

Water
Collagen - mainly type II
Proteoglycans - responsible for compressive properties

44
Q

What is fibrocartilage

A

Hybrid between hyaline and tendon cartilage
Bands of densely packed type I collagen
eg: intervertebral discs

45
Q

Catabolic factors of cartilage matrix turnover

A

Stimulate proteolytic enzymes

Inhibit proteoglycan synthesis

46
Q

Anabolic factors of cartilage matrix turnover

A

Stimulate proteoglycan synthesis

47
Q

Markers of cartilage degeneration

A

Increased levels of type II collagen in synovial fluid (e.g. from cartilage erosion)
Increased levels of serum & synovial keratin sulphate

48
Q

Bone

A

Rigid, not permeable, has a blood supply

49
Q

Functions of bone

A

Support
Protection
Calcium store

50
Q

Outer layer of bone

A

Cortical bone

Makes up diaphysis (shaft)

51
Q

Inner layer of bone

A

Spongey

Fine meshwork of bone (aero bar appearance)

52
Q

What is a reflex?

A

Stereotyped response to a specific stimulus

53
Q

Stretch reflex

A

Causes contraction of stretched muscle

54
Q

How to elicit a stretch reflex

A

Tap the muscle tendon with a rubber hammer. this rapidly stretches the muscle resulting in its contraction

55
Q

Knee jerk

  • nerve involved
  • spinal nerve roots involved
A

Femoral nerve

L3, L4

56
Q

Ankle jerk

  • nerve involved
  • spinal nerve roots involved
A

Tibial nerve

S1, S2

57
Q

Biceps jerk

  • nerve involved
  • spinal nerve roots involved
A

Musculocutaneous nerve

C5, C6

58
Q

Intrafusal fibres

A

Muscle spindles

59
Q

Extrafusal fibres

A

Ordinary muscle fibres

60
Q

Nociceptive pain

A

Serves as an immediate warning that tissues have been damaged and could get damaged further
Protective signal
Initiates a withdrawal reflex

61
Q

Nociceptors

A

First order neurones that relay information to second order neurones.
The second order neurones ascend the spinal cord via 2 possible tracts to get to the CNS
- STT (spinothalmic tract) which transmits fast A-fibre
- SRT (spinoreticular tract) which transmits slow C-fibre

62
Q

What are nociceptors activated by?

A

Intense stimuli

63
Q

Inflammatory pain

A

Caused by activation of the immune system in injury or infection
Assists in healing of a damaged body part

64
Q

Pathological pain

A

Results from abnormal nervous system function

65
Q

Neuropathic pathological pain

A

Ongoing abnormal neuronal activity which results in spontaneous pain
(eg stroke)

66
Q

Dysfunctional pathological pain

A

No precipitating cause

67
Q

2 sub-types of nociceptor?

A

Alpha fibres

C-fibres

68
Q

Nociceptor alpha fibres

A

mediate fast pain which is localised (stabbing) and very painful

69
Q

Nociceptor C fibres

A

Mediate slow pain which is generalised (cramping)