UL 3 Station 4 - Muscles of the Hand

Question 1

The intrinsic muscles of the hand are located in what 5 compartments?

Answer 1

Thenar

Hypothenar

Adductor

Lumbricals (and long flexor tendons - central compartment)

Interosseous compartment

Question 2

The thenar muscles form the BLANK (2 words) on the BLANK part of the palm.

Answer 2

Thenar eminacne on the lateral part of the palm

Question 3

The thenar muscles are responsible for…

Answer 3

Apposition of the thumb

Question 4

What 3 muscles make up the thenar eminance of the thumb and roughly describe their locations?

Answer 4

Abductor pollicis brevis (more lateral)

Flexor pollicis brevis (more medial)

Opponens pollicis (most deep)

Question 5

Answer 5

Question 6

What nerve innervates all 3 muscles of the thenar eminance?

Answer 6

Median nerve

Question 7

Hypothenar muscles produce the BLANK (2 words) on the BLANK side of the palm.

Answer 7

Hypothenar eminance

Medial side of palm

Question 8

Name the 3 muscles that make up the hypothenar eminance. Roughly describe their locations.

Answer 8

Abductor digiti minimi

Flexor digiti minimi

Opponens digiti minimi

Question 9

Which nerve innervates all the hypothenar muscles?

Answer 10

Question 11

The adductor pollicis muscle is made up of how many heads? What are their names? What nerve innervates it? What is its action on the thumb?

Answer 11

Transverse head

Oblique head

Innervated by ulnar nerve

Adducts the thumb (towards lateral border of palm)

Question 12

How many lumbrical muscles are there?

Answer 12

4

Question 13

From which long flexor tendon do these lumbricals originate?

Answer 13

Tendon of flexor digitorum profundus

Question 14

Action of lumbricals?

Answer 14

Flex the fingers at the metacarpo-phalangeal joint (knuckles)

and simultanesously extend the interphalangeal joints of 2nd to 5th digits

Question 15

Innervation of lumbricals?

Answer 15

Medial two - ulnar

Lateral two - median

Question 16

Answer 16

Question 17

Interossi muscles are present between…?

How many are there?

Answer 17

The metacarpal bones

Inter = between Ossei = metacarpal bones

4 dorsal and 3 palmar - dorsal easy to spot on specimen

Question 18

How to spot interossei muscles?

Answer 18

Honestly I have no clue how to differentiate them from lumbricals

• I think lumbrical tendons will stretch to right inbetween the distal and proximal interphalangeal joints and the interossei stops round about the metacarpophalangeal joints

Question 19

Interossei functions? Good mnemonic to rememebr this?

Answer 19

Dorsal - abducts the fingers (DAB for Dorsal AB)

Palmar adducts the fingers (PAD for Palmar AD

Question 20

Interossei innervation? Name the nerve and the spinal segmental legels that provide the fibres to this nerve

Answer 20

Ulnar nerve - C8 and T1

Question 21

What brachial plexus trunk is affected when the interossei muscles are paralysed and what is the name of this paralysis?

Answer 21

Lower trunk - c8 and t1

Klumpkes paralysis