Short Muscles

Question 1

lumbricals 1 and 2

Answer 1

PA:
+ lateral two tendons of flexor digitorum profundus (as unipennate muscles)

DA:
+ lateral sides of extensor expansions of 2nd-5th fingers

N:
+ median nerve (C8, T1*)

A:
+ flex metacarpophalangeal joints
+ extend interphalangeal joints of 2nd-5th fingers

Question 2

lumbricals 3 and 4

Answer 2

PA:
+ medial 3 tendons flexor digitorum profundus (as bipennate muscles)

DA:
+ lateral sides of extensor expansions of 2nd-5th fingers

N:
+ deep branch of ulnar nerve (C8, T1*)

A:
+ flex metacarpophalangeal joints
+ extend interphalangeal joints of 2nd-5th fingers

Question 3

dorsal interossei 1-4

Answer 3

PA:
+ adjacent sides of two metacarpals (as bipennate muscles)

DA:
+ bases of proximal phalanges
+ extensor expansions of 2nd-4th fingers

N:
+ deep branch of ulnar nerve (C8, T1*)

A:
+ abduct 2nd-4th fingers from axial line
+ act with lumbricals in flexing metacarpophalangeal joints and extending interphalangeal joints

Question 4

palmar interossei 1-3

Answer 4

PA:
+ palmar surfaces of 2nd, 4th and 5th metacarpals (as unipennate muscles)

DA:
+ bases of proximal phalanges
+ extensor expansions of 2nd, 4th, and 5th fingers

N:
+ deep branch of ulnar nerve (C8, T1*)

A:
+ adduct 2nd, 4th, and 5th fingers toward axial line
+ assist lumbricals in flexing metacarpophalangeal joints and extending interphalangeal joints