MSK

Question 0

What nerve innervates the anterior forearm?

Answer 0

Mainly the median nerve (C6-T1)
BUT
lateral part of flexor digitorum profundus and flexor carpi ulnaris are innervated by the ulnar nerve (C7-T1)

Question 1

What nerve innervated the posterior forearm?

Answer 1

The radial nerve (C5-T1 although most of them include at least C7)

Question 2

What muscle innervated the anterior upper arm?

Answer 2

Musculocutaneous (C5-C6)

Question 3

What muscle innervates the posterior upper arm?

Answer 3

The radial nerve (C5-T1 although posterior upper arm only uses C6-C8)

Question 4

What are the 3 muscles of the upper anterior arm?

Answer 4

Coracobrachialis
Biceps brachii
Brachialis

Question 5

What are the 2 muscles of the posterior upper arm?

Answer 5

Triceps brachii

Anyone us

Question 6

What are the muscles of the 1st layer of the anterior forearm?

Answer 6

Pronator teres
Flexor carpi radialis
Palmaris longus
Flexor carpi ulnaris

Question 7

What are the muscles of the 2nd layer of the anterior forearm?

Answer 7

Flexor digitorum superficialis

Question 8

What are the muscles of the third layer of the anterior forearm?

Answer 8

Flexor digitorum profundus

Flexor pollicis longus

Question 9

What are the muscles of the fourth and deepest layer of the anterior forearm?

Answer 9

Pronator quadratus

Question 10

What are the muscles of the superficial layer of the posterior forearm?

Answer 10

Extensor digiti minimi
Extensor digitorum
Extensor carpi radialis longus
Extensor carpi radialis brevis
Extensor carpi ulnaris
Anconeus
Brachioradialis

Question 11

What are the muscles of the deep layer of the posterior forearm?

Answer 11

Extensor indices
Abductor pollicis longus
Extensor pollicis longus
Extensor pollicis brevis
Supinator

Question 12

Where do most of the flexor of the wrist emerge?

Answer 12

Medial epicondyle of humerus EXCEPT pronator quadratus

Question 13

Where do most of the posterior forearm muscles originate and which don’t fit this pattern?

Answer 13

All the superficial layer originate at the lateral epicondyle of the humerus

Question 14

What are the intrinsic muscles of the hand and their innervation?

Answer 14

Palmaris brevis. Ulnar nerve
Lumbricals. Lateral 2 = median, medial 2
= ulnar
Interossei (dorsal and palmar). Both ulnar nerve
Opponens pollicis. Median nerve
Abductor pollicis brevis. Median nerve
Flexor pollicis brevis. Median nerve
Opponens digiti minimi. Ulnar nerve
Abductor digiti minimi. “
Flexor digiti minimi brevis “
Adductor pollicis. “

Question 15

What is the function of the lumbricals and the interossei of the hand?

Answer 15

Lumbricals extend IP joint but flex MCP

Dorsal interossei abduct fingers 2, 3 and 4

Palmar interossei adduct fingers 2, 3 and 4

Question 16

What type of grip do the 2 types of hand muscle focus on?

Answer 16

Intrinsic - precision grip

Extrinsic - power grip

Question 17

What order are energy stores used to supply a working muscle?

Answer 17

First few seconds - ATP
Phosphorylation of ADP by CrP using CK
Anaerobic respiration
Aerobic respiration

Question 18

What are the muscle arrangements and examples of these?

Answer 18

Unipennate (lateral 2 lumbricals, extensor digitorum)
Bipennate (medial 2 lumbricals)
Multipennate (deltoids)
Circular (orbicularis oris)
Fusiform (biceps brachii)
Convergent (pec major)

Question 19

What is a fixator muscle?

Answer 19

Muscles which stabilise the action of primer movers at joints that aren’t intending to move.

Question 20

What is an agonist in terms of muscle?

Answer 20

The prime mover of the joint.

Question 21

What is an antagonist in terms of muscle?

Answer 21

A muscle which opposes the prime movers

Question 22

What is a synergist muscle?

Answer 22

One which assists the prime mover by neutralising any extra motion.

Question 23

What is the fulcrum?

Answer 23

The pivotal point upon a muscular force

Question 24

What are the classes of movement and give examples?

Answer 24

First class

• force, fulcrum, load
• head movement

Second class

• force, load, fulcrum
• ankle joint

Third class

• fulcrum, force, load
• biceps moving elbow

Question 25

What are the types of muscle contraction and their features?

Answer 25

Isometric - muscle length stays same, tension is variable

Isotonic - muscle length changes, tension is constant

• -> 2 types
  1) . Concentric - muscle shortens to exert a force
  2) . Eccentric - muscle lengthens to exert a force

Question 26

What can measure electrical activity in a muscle?

Answer 26

EMG (electromyograph)

Question 27

How does feedback from muscles occur?

Answer 27

Proprioreceptors are within muscle fibres forming spindles that are associated with a nerve ending.
The nerve ending can detect force the muscle is exerting and its arrangement in 3D space, and sends this information either via a reflex, or to the brain via spinal cord.
This has a role in fibre recruitment

Question 28

How can extra muscle fibres be recruited?

Answer 28

1) . Temporal summation
- fire more a.p.

2) . Spatial summation
- activate more neurones

Question 29

Why do muscles have a baseline tone?

Answer 29

Muscle elasticity

Motor neurone activity

Question 30

What controls muscle tone?

Answer 30

The motor control centre of the brain.

It receives info from the afferent fibre signals via CNS

Question 31

What is hypotonia and how may it occur?

Answer 31

Loss of baseline tone of muscle

• damage to supplying nerve (motor neurone)
• damage to spinal cord
• damage to cerebellum
• damage to afferent nerve
• muscle degeneration

Question 32

What are the “crosstalk” signalling molecules between neurones and muscle?

Answer 32

Cytokines
IGF
Neutrophins

Question 33

How does nerve damage cause atrophy?

Answer 33

It prevents crosstalk between the neurone and its fibres = no longer stimulated = atrophy.