Midterm- Forearm Muscles

Question 1

Pronator teres

Answer 1

Origin: ∗ Humeral head: medial epicondyle of humerus
∗ Ulnar head: Coranoid process
Insertion: Lateral surface of radius distal to supinator insertion
Action: ∗ Pronation of forearm ∗ Flexion of forearm
Innervation: Median C6,C7

Question 2

Flexor carpi radialis

Answer 2

Origin: medial epicondyle of humerus
Insertion: Base of 2nd metacarpal
Action: Flexion of hand at wrist, abduction of hand at wrist (radial deviation)
Innervation:Median C6,C7

Question 3

Palmaris Longus

Answer 3

Origin: medial epicondyle of humerus
Insertion: Palmar aponeurosis
Action: flexion of hand at wrist, tenses palmar apneurosis
Innervation: median C6,C7

Question 4

Flexor carpi ulnaris

Answer 4

Origin: Humeral head: medial epicondyle of humerus
Ulnar head: olecranon
Insertion: pisiform, hook of hamate, 5th metacarpal
Action: flexion of hand at wrist, adduction of hand at wrist (ulnar deviation)
Innervation: Ulnar nerve C7, C8, T1

Question 5

Flexor digitorum superficialis

Answer 5

Origin: Humeroulnar head: medial epicondyle of humerus, coronoid process of ulna
Radial head: anterior, superior 1/2 of radius
Insertion: base of middle phalanx of digits 2-5
Action:flexion of middle phalanges of digits 2-5 at PIP joints, Flexion of proximal phalanges of digits 2-5 at MCP joint, Flexion of hand at wrist
Innervation: Median C8, T1

Question 6

Flexor digitorum profundus

Answer 6

Origin: proximal 2/3 of shaft of ulna, interosseous membrane
Insertion: base of distal phalanx of digits 2-5
Action: flexion of distal phalanges of digits 2-5 at DIP joints, Flexion of hand at wrist
Innervation: radial part; Median
ulnar part: ulnar C8,T1

Question 7

Flexor pollicis longus

Answer 7

Origin: Anterior surface of radius and adjacent interosseous membrane
Insertion: Base of distal phalanx of thumb (palmar surface)
Action: Flexion of thumb at CMC, MCP, and IP joints
Innervation:Median C7,C8

Question 8

Pronator quadratus

Answer 8

Origin: Distal 1/4 of anterior surface of ulna
Insertion: Distal 1/4 of anterior surface of radius
Action: Pronation of forearm, stabilization of distal radioulnar joint
Innervation: median C7, C8

Question 9

Brachioradialis

Answer 9

Origin: Proximal 2/3 lateral supraepicondylar ridge of humerus
Insertion: lateral surface of distal radius proximal to styloid process
Action: flexion of forearm at the elbow
Innervation: Radial C5, C6

Question 10

Extensor carpi radialis longus

Answer 10

Origin: lateral supracondylar ridge of humerus
Insertion: dorsum of base of 2nd metacarpal
Action: extension of hand at wrist, abduction of hand at wrist (radial deviation), active during fist clenching
Innervation: Radial C7, C8

Question 11

Extensor carpi radialis brevis

Answer 11

Origin: lateral epicondyle of humerus
Insertion: dorsum of base of 3rd metacarpal
Action: extension of hand at wrist, abduction of hand at wrist (radial deviation), active during fist clenching
Innervation: Radial C7, C8

Question 12

Extensor digitorum

Answer 12

Origin: lateral epicondyle of humerus
Insertion: extensor expansion of digits 2-5 (to dorsum of proximal, middle, and distal phalanges)
Action: Extension of digits 2-5 at MCP and IP joints, extension of hand at wrist
Innervation: Radial C7, C8

Question 13

Extensor digiti minimi

Answer 13

Origin: lateral epicondyle of the humerus
Insertion: extensor aspect of 5th digit
Action: extension of 5th digit at MCP and IP joints
Innervation: Radial C7, C8

Question 14

Extensor carpi ulnaris

Answer 14

Origin: lateral epicondyle of humerus, posterior border of ulna
Insertion: dorsal aspect of base of 5th metacarpal
Action: extension of hand at wrist, abduction of hand at wrist (ulnar deviation), active during fist clenching
Innervation: Radial C7, C8

Question 15

Supinator

Answer 15

Origin: Lateral epicondyle of humerus, radial collateral and annular ligaments, supinator fossa
Insertion: lateral, posterior, and anterior surface of proximal 1/3 of radius
Action: supination of forearm
Innervation: Radial C6, C7, C8

Question 16

Extensor indicis

Answer 16

Origin: Posterior surface of distal 1/3 of ulna, interosseous membrane
Insertion: extensor expansion of 2nd digit
Action: extension of 2nd digit at MCP and IP joints
Innervation: Radial C7, C8

Question 17

Abductor pollicis longus

Answer 17

Origin: posterior surface of middle 1/3 of radius, ulna, & interosseous membrane
Insertion: Base of 1st metacarpal
Action: Abduction of thumb at CMC joint (radial deviation), extension of thumb at CMC joint
Innervation: Radial C7, C8

Question 18

Extensor pollicis brevis

Answer 18

Origin: Posterior surface of distal 1/3 of radius, interosseous membrane
Insertion: dorsum of base of proximal phalanx of thumb
Action: Extension of proximal phalanx of thumb at MCP joint, assists extension of hand at CMC
Innervation: Radial C7, C8

Question 19

Extensor pollicis longus

Answer 19

Origin: posterior surface of middle 1/3 of ulna, interosseous membrane
Insertion: Dorsum of base of distal phalanx of thumb
Action: extension of distal phalanx of thumb at IP joint, assists extension of hand at MCP and CMC joints
Innervation: Radial C7, C8