MSK Session 6- The Hand

Question 0

What are the three hypo thenar muscles (lateral to medial)?

Answer 0

• flexor digiti minimi brevis
• abductor digiti minimi
• opponens digiti minimi

Question 1

What are the three thenar muscles (lateral to medial)?

Answer 1

• opponens pollicis
• abductor pollicis brevis
• flexor pollicis brevis

Question 2

What does the median nerve innervate in the hand?

Answer 2

• lumbricals 1 and 2
• opponens pollicis
• abductor pollicis brevis
• flexor pollicis brevis

Question 3

What Innervates the hypothenar muscles?

Answer 3

The ulnar nerve

Question 4

What is the role of adductor pollicis and what is it innervated by?

Answer 4

• adducts the thumb

- ulnar nerve

Question 5

What are the two roles of the lumbricals?

Answer 5

• flexion of the metacarpophalangeal joints

- extension of the interphalangeal joints

Question 6

Which lumbricals are innervated by the ulnar and median nerves?

Answer 6

• ulnar nerve= 3rd and 4th lumbricals

- median nerve= 1st and 2nd lumbricals

Question 7

What is the role of the palmar interossei muscles and how many are there?

Answer 7

• adduct the fingers

- 3

Question 8

What is the role of the dorsal interossei muscles and how many are there?

Answer 8

• abduct the fingers

- 4

Question 9

Which nerve Innervates the interossei muscles?

Answer 9

Ulnar nerve

Question 10

What is the palmaris longus continuous with?

Answer 10

The palmaris longus tendon and the flexor retinaculum

Question 11

What is the function of the palmar aponeurosis?

Answer 11

To cover and protect underlying tissues, flexor tendons, blood vessels and digital nerves.

Question 12

What is the dorsal arterial supply of the hand?

Answer 12

The superficial and deep palmar arches

Question 13

Which structures enter the hand through Guyon’s canal?

Answer 13

The ulnar artery and nerve

Question 14

Which nerve enters the hand through the carpal tunnel?

Answer 14

The median nerve

Question 15

Which bones does the flexor retinaculum articulate with to form the carpal tunnel?

Answer 15

• lateral: scaphoid and trapezoid

- medial: pisiform and hook of hamate

Question 16

What causes carpal tunnel syndrome?

Answer 16

A lesion that reduces the size of the tunnel, or increases the size of structures within it.

• fluid retention
• infection
• excessive exercise of the fingers

Question 17

What I carpal tunnel syndrome?

Answer 17

Compression of the median nerve

Question 18

What are the consequences of carpal tunnel syndrome?

Answer 18

• Parasthesia- tingling
• hyposthesia- diminished sensation
• anaesthesia- complete loss of sensation

Question 19

If the median nerve is compressed, which digits are affected by carpal tunnel syndrome?

Answer 19

The lateral 3 1/2 digits

Question 20

Does a superficial laceration if the wrist cause loss of motor function? Why/why not?

Answer 20

No
Because a superficial lesion will only damage the palmar cutaneous branch of the median nerve. Therefore only causes a loss of sensation to the Palm.

Question 21

Does a deep laceration to the wrist cause loss of motor function? Why/why not?

Answer 21

Yes
Because the median nerve is damaged.
Therefore the motor function of the lateral 3 1/2 digits are affected -> ape thumb

Question 22

What is boxer’s fracture?

Answer 22

Fracture of the 5th metacarpal due to a punch delivered with a closed, abducted fist.

Question 23

Where would test the function of the median nerve?

Answer 23

2nd metacarpal fingertip

Question 24

Where would you test the radial nerve?

Answer 24

The dorsum of the hand- anatomical snuffbox area.

Question 25

Where would you test the ulnar nerve?

Answer 25

The tip of the 5th metacarpal

Question 26

What is Erb’s palsy and which nerves are affected?

Answer 26

A upper brachial plexus injury which is caused by an excessive angle between the neck and shoulder.
It affects the musculocutaneous and axillary nerves.
It results in the ‘waiters tip’ position.

Question 27

What is Klumpke palsy and which nerves are affected?

Answer 27

It is a lower brachial plexus injury.
The ulnar and median nerves are affected.
It results in ‘ulnar claw’

Question 28

How do people with ulnar nerve damage at the elbow present?

Answer 28

Can’t trip paper laced between their fingers because they cannot abduct and adduct the fingers.

Question 29

How do people with ulnar nerve injury at the wrist present?

Answer 29

Ulnar claw

Question 30

How do people with median nerve damage at the elbow present?

Answer 30

Hand of benediction

Question 31

How do people with median nerve damage at the wrist present?

Answer 31

Hand of benediction and a wasted thenar eminence.