Hand

Question 1

Thenar muscles

Answer 1

Abductor pollicis brevis
Flexor pollicis brevis
Opponens policis
Adductor pollicis

Question 2

Abductor pollicis brevis

Answer 2

Origin:
* Scaphoid tubercle + trapezium
* Flexor retinaculum
Insertion: Lateral portion of the base of the proximal phalanx of thumb
Innervation: Median nerve (recurrent branch)
Blood supply: Superficial palmar arch
Action: Abduction of thumb

Question 3

Opponens Pollicis

Answer 3

Origin: Flexor retinaculum + tubercle of trapezium
Insertion: lateral surface of the 1st metacarpal
Innervation: median nerve (recurrent branch)
Blood supply: superficial palmar arch
Action: opposition of the thumb

Question 4

Flexor pollicis brevis

Answer 4

Origin:
* Superficial head: flexor retinaculum
* Deep head: tubercle of trapezium
Insertion: MCPJ of thumb (radial sesamoid bone of metacarpal)
Innervation:
* Superficial head: median nerve (recurrent branch)
* Deep head: ulnar nerve (deep branch)
Blood supply: Superficial palmar arch
Action: Flexion of MCPJ of thumb

Question 5

Adductor Pollicis Brevis

Answer 5

Origin:
* Oblique head: shaft of 3rd metacarpal
* Transverse head: base of 2nd and 3rd metacarpals
Insertion: MCPJ of thumb (ulnar sesamoid bone of metacarpal)
Innervation: ulnar nerve
Blood supply: deep palmar arch
Action: adduction of thumb

Question 6

Hypothenar muscles

Answer 6

Abductor Digiti Minimi
Flexor Digiti Minimi Brevis
Opponens Digiti Minimi
Palmaris Brevis

Question 7

Innervation of the hypothenar muscles

Answer 7

All ulnar nerve

Question 8

Innervation of the thenar muscles

Answer 8

All median apart from the adductor pollicis brevis and the deep head of the flexor pollicis brevis

Question 9

Abductor digiti minimi

Answer 9

Origin: pisiform + pisohamate ligament
Insertion: base of proximal phalanx of 5th digit
Innervation: ulnar nerve
Blood supply: deep palmar arch
Action: abduction of the little finger

Question 10

Flexor Digiti Minimi Brevis

Answer 10

Origin: Hook of hamate + flexor retinaculum
Insertion: base of the proximal phalanx of 5th digit
Innervation: ulnar nerve
Blood supply: deep palmar arch
Action: flexion of MCPJ of little finger

Question 11

Opponens Digiti Minimi

Answer 11

Origin: Hook of hamate + flexor retinaculum
Insertion: ulnar margin of 5th metacarpal
Innervation: ulnar nerve
Blood supply: deep palmar arch
Action: opposition of the little finger

Question 12

Palmaris brevis

Answer 12

Origin: palmar aponeurosis + flexor retinaculum
Insertion: dermis of the skin on the medial margin of the hand
Innervation: ulnar nerve
Blood supply: Superficial palmar arch
Action: Wrinkles the skin of the hypothenar eminence and deepens the curvature of the hand, improving grip.

Question 13

Innervation of the forearm muscles

Answer 13

All median apart from:

1. The ulnar sides of the FDP
2. The FCU

Question 14

Mesothenar muscles

Answer 14

Lumbricals
Dorsal interosseous muscles
Palmar interosseous muscles

Question 15

Innervation of the mesothenar muscles

Answer 15

Ulnar apart from the 2 radial heads of the lumbricals which is median nerve

Question 16

Lumbricals

Answer 16

Origin: Radial aspect of FDP tendon
Insertion: radial aspect of extensor hood 2nd - 5th digit
Innervation: radial 2 heads: median nerve; ulnar 2 heads: ulnar nerve
Blood supply: deep palmar arch
Action: Flexion of MCPJ & Extension of IPJ

Question 17

Number of dorsal interosseous muscles

Answer 17

4

Question 18

Number of palmar interosseous muscles

Answer 18

3

Question 19

Dorsal interosseous muscles

Answer 19

Origin: shafts of metacarpals
Insertion: 1 + 2 radial surface of proximal phalanx; 3 + 4 ulnar surface of proximal phalanx via extensor hood
Innervation: ulnar nerve
Action: abduction + assist in flexion of MCPJ and extension of IPJ (lumbricals)

Question 20

Palmar interosseous muscles

Answer 20

Origin:
* Metacarpal shafts (ulnar/medial surface for index finger + radial/lateral surface for ring and little finger).
Insertion:
* Proximal phalanx via extensor hood
o Index finger (ulnar/medial surface)
o Ring + little finger (radial/lateral surface)
Innervation: ulnar nerve
Blood supply: palmar metacarpal arteries
Action: Adduction of digits. Assists in flexion of the MCPJs + extension of the IPJ (helps lumbricals)