Miscellaneous

Question 1

Lumbricals

Answer 1

Origin:
1st and 2nd lumbrical: lateral 2 tendons of flexor digitorum profundus
3rd and 4th lumbrical: medial 3 tendons of flexor digitorum profundus

Insertion:
1st and 2nd lumbrical: lateral sides of extensor expansion of digits 2 and 3
3rd and 4th lumbrical: lateral side of extensor expansion of digits 4 and 5

Innervation:
1st and 2nd lumbrical: digital branches of median nerve
3rd and 4th lumbrical: deep branch of ulnar nerve

Blood Supply: superficial and deep palmar arches

Action: extends digits at IP and flex MCP

Question 2

Dorsal Interossei

Answer 2

Origin: adjacent sides of two metacarpal bones

Insertion: base of proximal phalanges and extensor expansion of digits 2-4

Innervation: deep branch of ulnar nerve

Blood Supply: deep palmar arch

Action: abduct digits from 3rd digit, flex digits at MCP, extend digits at IP

Question 3

Palmar Interossei

Answer 3

Origin: sides of metacarpals of 2,4,5

Insertion: bases of proximal phalanx of digits 2,4,5 and extensor expansion of digits 2,4,5

Innervation: deep branch of ulnar nerve

Blood Supply: deep palmar arch

Action: adducts digits toward 3rd digit, flex digits at MCP, and extends digits at IP

Question 4

Adductor Pollicis

Answer 4

Origin: oblique head - bases of 2nd metacarpals and capitate and adjacent bones, transverse head - anterior surface of 3rd metacarpal

Insertion: medial side of base of proximal phalanx of thumb

Innervation: deep branch of ulnar nerve

Blood Supply: deep palmar arch

Action: adducts thumb

Question 5

Palmaris Brevis

Answer 5

Origin: palmar aponeurosis and flexor retinaculum

Insertion: skin of medial border of palm

Innervation: superficial palmar branch of ulnar nerve

Blood Supply: superficial palmar arch

Action: deepens hollow of hand and assists grip