Palmar Muscles of the Hand

Question 1

Name muscle #1

Answer 1

Flexor Retinaculum

Question 2

Name muscle #2

Answer 2

Opponens Pollicis

Question 3

Name Muscle #3

Answer 3

Abductor Pollicis Brevis

Question 4

Name Muscle #4

Answer 4

Flexor Pollicis Brevis (superficial head)

Question 5

Name muscle #5

Answer 5

Adductor Pollicis (oblique head)

Question 6

Name muscle #6

Answer 6

Adductor Pollicis (transverse head)

Question 7

Name muscle #7

Answer 7

1st dorsal interosseus

Question 8

Name muscle #8

Answer 8

Abductor digiti minimi

Question 9

Name muscle #9

Answer 9

Flexor digiti minimi

Question 10

Name muscle #10

Answer 10

Opponens digiti minimi

Question 11

Name muscle #11

Answer 11

lumbricals

Question 12

Name muscle #12

Answer 12

Deep transverse metacarpal 1

Question 13

If you remove the superficial flexor pollicis brevis and abductor pollicis brevis, what will you be able to see beneath?

Answer 13

Flexor pollicis brevis (deep head) and more of the opponens pollicis

Question 14

What are the 3 thenar muscles and what nerve innvervates them? Exception?

Answer 14

• Abductor pollicis brevis, opponens pollicis, and flexor pollicis brevis
• They are innvervated by the median nerve.
• Exception: deep head of the flexor pollicis brevis is innervated of the ulnar nerve.

Question 15

What are the hypothenar muscles? What are they innvervated by?

Answer 15

• Flexor digiti minimi brevis, abductor digiti minimi, and opponens digiti minimi.
• They are all innervated by the ulnar nerve.

Question 16

What are the 4 lumbricals? What’s their innervation?

Answer 16

• The 4 lumbricals link the extensor tendons to the flexor tendons. SO they originate at the tendons of the flexor digitorum profundus and insert on the lateral side of the extensor digitorum.
• Innervation: Lateral two (index and middle) are innvervated by the median nerve. Medial two (pinky and ring finger) are innervated by the ulnar nerve.

Question 17

What’s the action of the lumbricals?

Answer 17

They extend the the fingers at the interphalangeal joints and weakly flex fingers at metacarpophalangeal joint.

Question 18

Which is responsible for adduction and which is responsible for abduction?

Answer 18

Palmar Adduct

Dorsal Abduct

Question 19

Interossei Muscles… What are the two groups? How do they differ? What are they innervated by?

Answer 19

• Interossei muscles are located between the metacarpals.
• The two groups are the doral interossei and palmar interossei.
• They differ because there are 4 dorsal interossei muscles, but only 3 palmar. Middle finger does not have palmar muscle.
• They are innervated by the ulnar nerve.

Question 20

What are other muscles of the palm? What is the innvervation?

Answer 20

Palmaris brevis and adductor pollicis. They are both innvervated by the ulnar nerve.

Question 21

What causes carpal tunnel syndrome? What are the presenting symptoms?

Answer 21

Carpal tunnel is caused by compression of the median nerve. It causes neuralgia in the hand and diminished tactile sensation to lateral 3.5 digits and first two lumbricals.

Question 22

What causes Benediction Hand?

Answer 22

Cubital fossa injury to median nerve. Lack of sensation on lateral side of hand.

Question 23

What causes claw hand?