Forearm Flexors

Question 1

Which muscles are superficial flexors?

Answer 1

Pronator teres, flexor carpi radialis, palmaris longus, flexor carpi ulnaris

Question 2

What are the origins of pronator teres?

Answer 2

Humeral head: medial humeral epicondyle

Ulnar head: coronoid process of the ulna

Question 3

What does pronator teres insert on?

Answer 3

Lateral aspect of radius

Question 4

What is the action of pronator teres?

Answer 4

Pronate and flex the forearm

Question 5

What innervates most of the forearm flexors?

Answer 5

Median nerve

Exceptions: flexor carpi ulnaris, medial part of flexor digitorum profundus

Question 6

What are the attachment sites of flexor carpi radialis?

Answer 6

O: medial humeral epicondyle
I: ventral aspect of the base of the 2nd metacarpal

Question 7

What is the action of flexor carpi radialis?

Answer 7

Flex forearm

Flex and abduct the hand at the wrist

Question 8

What are the attachment sites for palmaris longus?

Answer 8

O: medial humeral epicondyle
I: palmar aponeuroses and flexor retinaculum

Question 9

What is the action of palmaris longus?

Answer 9

Flexor forearm

Flex hand and tenses the palmar aponeurosis

Question 10

What are the origins for flexor carpi ulnaris?

Answer 10

Humeral head: medial humeral epicondyle

Ulnar head: olecranon and posterior ulna

Question 11

What is the insertion site for flexor carpi ulnaris?

Answer 11

Pisiform

Hook of hamate and base of 5th metacarpal

Question 12

What is the action of flexor carpi ulnaris?

Answer 12

Flex forearm

Flex and adduct the hand at the wrist

Question 13

What innervates flexor carpi ulnaris?

Answer 13

Ulnar N

Question 14

Which muscle is in the intermediate layer of forearm flexors?

Answer 14

Flexor digitorum superficialis

Question 15

What are the origins for flexor digitorum superficialis?

Answer 15

Humeroulnar head: medial humeral epicondyle and coronoid process of the ulna
Radial head: superior half of anterior aspect of the radius

Question 16

What is the insertion site for flexor digitorum superficialis?

Answer 16

Bifed insertion on the intermediate phalanges of digits 2-5

Question 17

What is the action of flexor digitorum superficialis?

Answer 17

Flex forearm
Flex hand at wrist
Flexor proximal and intermediate phalanges of digits 2-5 at the MP and PIP joints respectively

Question 18

Which muscles are in the deep layer of forearm flexor muscles?

Answer 18

Flexor digitorum profundus, flexor pollicis longus and pronator quadratus

Question 19

What are the attachment sites for flexor digitorum profundus?

Answer 19

O: proximal ulna and interosseous membrane
I: ventral aspect of bases of distal phalanges of digits 2-5 (the tendon passes through bifed tendon of FDS to its insertion)

Question 20

What is the action of flexor digitorum profundus?

Answer 20

Flex the hand at the wrist

Flex all phalanges of digits 2-5 at the MP, PIP and DIP

Question 21

What innervates the flexor digitorum profundus?

Answer 21

Lateral part: anterior interosseous N of the median N

Medial part: ulnar N

Question 22

What are the attachment sites for flexor pollicis longus?

Answer 22

O: anterior aspect of the radius and interosseous membrane
I: ventral aspect of the base of the distal phalanx of the pollux

Question 23

What is the action of flexor pollicis longus?

Answer 23

Flex the hand
Flex and abduct the 1st metacarpal at the 1st carpometacarpal joint
Flex both phalanges of the pollux at the intercarpal joint

Question 24

What innervates most of the deep flexor muscles?

Answer 24

Anterior interosseous N of the median N

Question 25

What are the attachment sites for pronator quadratus?

Answer 25

O: anterior aspect of the distal ulna
I: anterior aspect of the distal radius

Question 26

What is the action of pronator quadratus?

Answer 26

Pronate forearm

Deep fibers hold the ulna and radius together