Hand

Question 1

Palmaris brevis

Answer 1

Attachments:
- flexor retinaculum and medial border of palmar aponeurosis
- dermis of medial border of hand
Actions:
- deepens groove along medial aspect of hyperthenar eminence, wrinkles skin and slightly accentuates eminence
- May contribute to grip
Innervation:
- superficial branch of the ulnar nerve C8, T1

Question 2

Flexor pollicis brevis

Answer 2

Attachments:
- flexor retinaculum, tubercles of trapezium and trapezoid 
- lateral aspect of base of 1st proximal phalanx 
Actions:
- flexion of 1st digit
Innervation:
- median nerve C8, T1
- deep head often ulnar nerve

Question 3

Abductor pollicis brevis

Answer 3

Attachments:
- flexor retinaculum, tubercles of trapezium and scaphoid
- lateral aspect base of 1st proximal phalanx
Actions:
- abducts 1st digit
- assists in opposition by rotating 1st digit medially
Innervation:
- median nerve C8, T1

Question 4

Opponens pollicis

Answer 4

Attachments:
- flexor retinaculum, tubercles of trapezium and scaphoid
- lateral surface of 1st metacarpal
Actions:
- opposes (draws medially and medially rotates) 1st metacarpal
Innervation:
- median nerve C8, T1

Question 5

Adductor pollicis

Answer 5

Attachments:
- oblique head: capitate, bases of metacarpals 2 & 3
- transverse head: anterior shaft of 3rd metacarpal
- medial aspect of base of 1st proximal phalanx
Actions:
- adducts 1st digit
Innervation:
- deep branch of ulnar nerve C8, T1

Question 6

Flexor digiti minimi brevis

Answer 6

Attachments:
- hook of hamate and flexor retinaculum 
- medial aspect of base of 5th proximal phalanx
Actions:
- flexion of 5th proximal phalanx 
Innervation:
- deep branch of ulnar nerve C8, T1

Question 7

Abductor digiti minimi

Answer 7

Attachments:
- pisiform 
- medial aspect of base of 5th proximal phalanx 
Actions:
- abducts 5th digit
Innervation:
- deep branch of ulnar nerve C8, T1

Question 8

Opponens digiti minimi

Answer 8

Attachments:
- hook of hamate and flexor retinaculum
- medial border of 5th metacarpal 
Actions:
- opposes (flexes and laterally rotates) 5th metacarpal 
Innervation:
- deep branch of ulnar nerve C8, T1

Question 9

Lumbricals

Answer 9

Attachments:
- tendons of flexor digitorum profundus
- lateral aspect of extensor expansion of digits 2-5
Actions:
- flexion of metacarpophalangeal joints of digits 2-5
- extension of interphalangeal joints of digits 2-5
Innervation:
- 1&2: median nerve C8, T1
- 3&4: deep branch of ulnar nerve C8, T1

Question 10

Palmar interosseous muscles

Answer 10

Attachments:
- 1: medial aspect of 2nd metacarpal 
- 2: lateral aspect of 4th metacarpal 
- 3: lateral aspect 5th metacarpal 
- base of proximal phalanx and extensor expansion of digits 2, 4 and 5 
Actions:
- adducts digits 2, 4 and 5
- assists in flexion of metacarpophalangeal joints and extension of interphalangeal joints
Innervation:
- deep branch of ulnar nerve C8, T1

Question 11

Dorsal interosseous muscles

Answer 11

Attachments:
- adjacent sides of 2 metacarpals (bipennate) 1:1&2, 2:2&3, 3:3&4, 4:4&5
- base of proximal phalanges 2-4, extensor expansion digits 2-4
Actions:
- abducts digits 2, 3, & 4
- assists in flexion at metacarpophalangeal joints and extension at interphalangeal joints
Innervation:
- deep branch of ulnar nerve C8, T1