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Flashcards in Week 4 Deck (46)
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1
Q

Name the superficial, intermediate, and deep muscles of the anterior compartment of the forearm

A

Superficial: flexor carpi ulnaris, palmaris longus, flexor carpi radialis, pronator teresIntermediate: flexor digitorum superficialisDeep: flexor digitorum profundus, flexor pollicus longus, pronator quadratus

2
Q

The superficial muscles in the anterior compartment of the forearm all originate from where?

A

They all originate from a common tendon, which originates from the medial epicondyle of the humerus (they hence all cross the elbow joint)

3
Q

What is the action of the flexor carpi ulnaris? What is its innervation?

A

Flexion and adduction at the wrist; ulnar nerve

4
Q

What is the action of the palmaris longus? What is its innervation?

A

Flexion at the wrist; median nerve

5
Q

Which structure is just underneath the palmaris longus? In what percentage of the population is the palmaris longus absent?

A

Median nerve; 15%

6
Q

What is the action of the flexor carpi radialis? What is its innervation?

A

Flexion and abduction at the wrist; median nerve

7
Q

What is the significance of the pronator teres with regard to the cubital fossa?

A

The lateral border of the pronator teres forms the medial border of the cubital fossa

8
Q

What is the action of the pronator teres? What is its innervation?

A

Pronates the forearm; median nerve

9
Q

Which two structures can be found passing between the two heads of the flexor digitorum superficialis?

A

The median nerve and ulnar artery

10
Q

To where do the four distal tendons of the flexor digitorum superficialis attach?

A

The middle phlanges of the four fingers

11
Q

What are the actions of the flexor digitorum superficialis?

A

Flexes the metacarpophalangeal joints, and proximal interphalangeal joints at the 4 fingers, and flexes the wrist

12
Q

What is the innervation of the flexor digitorum superficialis?

A

The median nerve

13
Q

The tendons of which two muscles pass through the carpal tunnel?

A

Flexor digitorum superficialis and flexor digitorum profundus

14
Q

To what do the tendons of the flexor digitorum profundus attach?

A

The distal phlanges of the four fingers

15
Q

What are the actions of the flexor digitorum profundus?

A

It is the only muscle that can flex the distal interphalangeal joints at the wrist; it also flexes the metacarpophalangeal joints and at the wrist

16
Q

What is the innervation of the flexor digitorum profundus?

A

Medial half is innervated by the ulnar nerve; the lateral half is innervated by the median nerve

17
Q

Describe the position of the flexor pollicis longus relative to the flexor digitorum profundus

A

The flexor pollicis longus lies laterally to the flexor digitorum profundus

18
Q

What are the actions of the flexor pollicis longus?

A

Flexes the interphalangeal joint and metacarpophalangeal joint of the thumb

19
Q

What is the innervation of the flexor pollicis longus?

A

Median nerve

20
Q

Describe the shape and location of the pronator quadratus

A

Square shaped muscle, lies deep to the tendons of the flexor digitorum profundus and flexor pollicis longus

21
Q

What is the action of the pronator quadratus? What is its innervation?

A

Acts to pronate the forearm; median nerve

22
Q

Which bones and what else form the carpal tunnel?

A

Pisiform, triquetrum, lunate, capitate, trapezoid trapezium, flexor retinaculum

23
Q

Which structures are of importance within the carpal tunnel?

A

Median nerve, tendons of the flexor digitorum superficialis, flexor digitorum profundus and flexor pollicis longus (9 tendons)

24
Q

What is carpal tunnel syndrome?

A

Compression of the median nerve within the carpal tunnel; thought to be due to increased pressure/thickening of tendon sheaths

25
Q

What are the typical signs of carpal tunnel syndrome?

A

Pins and needles in the sensory distribution of the median nerve and weakness of thenar muscles

26
Q

Why is some median nerve function retained in carpal tunnel syndrome?

A

The palmar cutaneous branch of the median nerve travels superficial to the flexor retinaculum

27
Q

Where is there sensation loss for people with Erb’s palsy?

A

The sensory areas that are supplied by the axillary and musculotaneous nerves; down the lateral side of the arm

28
Q

Does the musculotaneous nerve have any sensory function?

A

Lateral cutaneous nerve provides sensory function to the lateral side of the forearm

29
Q

Where would there be loss of sensation with a lesion of the musculotaneous nerve?

A

Lateral side of the forearm

30
Q

What sensory function does the axillary nerve contribute to?

A

Gives rise to lateral cutaneous nerve of arm; innervates the skin over the posterior deltoid, the ‘regimental badge’ area

31
Q

What sensory loss will occur with an injury to the axillary nerve?

A

If the lateral cutaneous nerve supply is interrupted, there will be loss of sensation over the regimental badge area

32
Q

Which to muscles does the median nerve travel in between as it passes through the forearm?

A

Flexor digitorum profundus and flexor digitorum superficialis

33
Q

Describe two important branches of the median nerve as it passes through the forearm, and their functions

A

Anterior interosseous nerve, supplying deep flexor muscles, and palmar cutaneous nerve, which innervates skin on the palmar, lateral aspect of the hand

34
Q

What are the respective areas supplied by the radial and ulnar arteries?

A

Radial: posterior aspect, Ulnar: anterior aspect

35
Q

What are some common risk factors for carpal tunnel syndrome?

A

TRAMP; trauma, rheumatoid arthritis, acromegaly, myxoedema, pregnancy

36
Q

Which myotome performs abduction of the arm at the glenohumeral joint?

A

C5

37
Q

Which myotome performs flexion of the forearm at the elbow joint?

A

Primarily C6 (some C5)

38
Q

Which myotome performs extension of the forearm at the elbow joint?

A

Mainly C7 (some 6/8)

39
Q

Which myotome performs flexion of the forearm of the fingers?

A

C8

40
Q

Which myotome performs abduction and adduction of the index, middle and ring fingers?

A

T1

41
Q

What is the cubital tunnel?

A

Formed by tendinous arch joing humeral and ulnar heads of the attachment of flexor carpi ulnaris; the median nerve enters the forearm through it

42
Q

Which myotome performs adduction at the shoulder?

A

C6, C7, (C8)

43
Q

Which myotome performs pronation?

A

C7, C8

44
Q

Which myotome performs supination?

A

C6

45
Q

What are the medial and lateral attachments of the flexor retinaculum?

A

Medially attached to the pisiform and hook of hamate; laterally attached to the tubercle of the scaphoid and trapezium bones

46
Q

Give causes of carpal tunnel syndrome

A

Tenosynovitis (thickening of synovium), repetitive trauma (compression forces and stretching), oedema, fractures, dislocations, inherited small bone fractures