Brainscape's Knowledge GenomeTM

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


See full index

Revision Notes - Year 1 > Wrist Injury - 112 > Flashcards

Wrist Injury - 112 Flashcards

0
Q

Describe (really simply) the structure of collagens

A

They are composed of 3 polypeptide chains wound into a triple helix

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

What is the most abundant class of proteins in the body?

A

Collagen

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

Collagen molecules are staggered to form fibrils. What cross links strengthen this assembly?

A

Lysine and hydroxylysine cross links

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

What is the role of tendons?

A

Link muscle to bone - have a high tensile strength to transmit muscle forces with minimal elongation

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

Describe the composition of tendons

A

Water = 55% wet weight.
Tendons consist of: collagen (mostly type I, which provides the tensile properties), elastin (provides the elastic properties), and proteoglycans (these bind water and help resist compression and regulate collagen fibril size).

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

Name some of the functions of tendons

A
  • Allow muscle belly to be away from site of action
  • Enable muscle pull to be focused
  • Eliminate the need for muscle to be an unnecessary length
  • Act as springs
    etc
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is present where the tendon inserts on the bone?

A

fibrocartilage - enthesis

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

What is the major proteoglycan of cartilage?

A

Aggrecan

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

What happens at myotendinous junctions?

A

Force is transferred from muscle to tendon

There is increased S/A for anchorage

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

What do ligaments connect?

A

Bone to bone

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

What is more vascular, ligaments or tendons?

A

Ligaments

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

Name some roles of ligaments

A
  • stabilise joints and guide joint motion

- supply proprioceptive information

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

What kind of cells do ligaments contain?

A

fibroblastic. They are mostly broad and flat and are more cartilage-like at bone insertion

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

What collagens do ligaments contain?

A

Type I (90%) and type III (10%)

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

Which glycosaminoglycan gives synovial fluid its lubricating properties?

A

Hyaluronan

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

What is a motor unit?

A

A single motor neurone and the muscle fibres it innervates

16
Q

What is a motor neurone pool?

A

All the motor neurones that supply 1 complete muscle

17
Q

What is a motor end plate?

A

The region of a muscle fibre membrane directly under terminal portion of an axon

18
Q

What is the NMJ?

A

The junction of the axon terminal with the motor end plate

19
Q

What is the resting potential and threshold potential for an AP at a motor nerve terminal? What happens when threshold potential is reached?

A

RP = -70mV
TP = -50mV
When threshold is reached an AP is fired

20
Q

What happens at the NMJ when an AP arrives?

A

Ca influxes, causing the release of ACh from vesicles.
ACh binds to nicotinic receptors on the motor end plate in the muscle fibre, causing Na influx.
This depolarises the membrane and generates an end plate potential

21
Q

What poison can block the ACh receptor?

A

Curare

22
Q

What are thin filaments in muscle fibres and what do they contain?

A

Actin. Also contain troponin and tropomyosin - which regulate contracion

23
Q

Describe the structure of a mysoin molecule

A

Thick filament with myosin heads extending from it. Each globular head has binding sites for actin and ATP

24
Q

During contraction, what happens to the sarcomere lenght,the H zone and the I band?

A

Sarcomere shortens, H zone and I band are both reduced

25
Q

Describe briefly the 4 steps of the cross bridge cycle in muscle contraction

A

1) Attachment of cross bridge to thin filament
2) Movement of cross bridge -> causes tension
3) detachment of cross bridge from thin filament
4) energising of cross bridge so cycle can repeat (ATP split to ADP and Pi)

26
Q

What is the role of calcium in muscle contraction?

A

Tropomyosin molecules block actin binding site. When Ca binds troponin, tropomyosin molecules are moved away from blocking actin.

27
Q

What is isometric contraction?

A

A muscle develops tension but does not shorten or lengthen. It stays constant in length. e.g. lifting an object that is too heavy

28
Q

What is muscle cramp?

A

Painful strong muscular contraction in response to ischaemia or metabolic disturbance

29
Q

What commonly occurs at the myotendinous junction and is associated with explosive activities and eccentric contractions?

A

Muscle strains/pulls

30
Q

What can be used to diagnose neuromuscular disorders?

A

Electromyography

31
Q

What is poliomyelitis?

A

A virus that destroys motor neurons -> affects lower motor neurons

32
Q

Name a disorder of the NMJ

A

Myasthenia gravis

33
Q

Name a disorder of the muscle fibres

A

Muscular dystrophy

Revision Notes - Year 1 (41 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions