Hand - Deep Muscles

Question 0

Palmar Interossei

Answer 0

Origin: Palmar Surface of Metacarpals 2 (Medial), 4 (Lateral), and 5 (Lateral)
Insertion: Proximal Phalanx of 2nd (Medial), 4th (Lateral), and 5th (Lateral) Digits and Dorsal Digiti Expansions of Same Digits
Action: Adducts Digits 2, 4, and 5; Flex MP and extend PIP and DIP
Nerve: Ulnar (via Deep Branch)

Question 1

Dorsal Interossei (4)

Answer 1

Origin: 2 Heads - Adjacent Sides of Metacarpals 1/2, 2/3, 3/4, 4/5
Insertion: Proximal Phalanx of 2nd (lateral side), 3rd (Medial and Lateral), and 4th (Medial) Digits and Dorsal Digiti Expansions of Same Digits
Action: Abducts 2nd, 3rd, and 4th Digits; Flex MP and extend PIP and DIP
Nerve: Ulnar (via Deep Branch)

Question 2

Lumbricals (4)

Answer 2

Origin: Tendons of Flexor Digitorum Profundis
Insertion: Lateral Side of Dorsal Digiti Expansions of the tendons of extensor digitorum
Action: Flex MP and extend PIP and DIP
Nerve: Lateral Half (1 and 2) are Median, Medial Half (3 and 4) are Ulnar (via Deep Branch)