KIN 100 - Muscles of the Anterior Forearm (Lecture 11)

Question 1

The forearm is divided into 2 muscle compartments, what are they divided by

Answer 1

Interosseous membrane

Question 2

What are the muscles in the superficial layer of the anterior forearm (4)

Answer 2

1. Pronator Teres
2. Flexor carpi radialis
3. Palmaris longus
4. Flexor carpi ulnaris

Question 3

What is the middle layer of the anterior forearm

Answer 3

Flexor digitorum superficialis

Question 4

What is the deep layer of the anterior forearm (3)

Answer 4

1. Flexor digitorum profundus
2. Flexor pollicis longus
3. Pronator quadratus

Question 5

What is the common flexor origin for the muscles of the anterior forearm

Answer 5

medial epicondyle of the humerus

Question 6

Pronator teres

Answer 6

proximal: common flexor origin and coronoid process of ulna

distal: mid-shaft radius on the lateral surface

Innervation: median nerve

Action: pronates forearm and assists with elbow flexion

Question 7

Flexor carpi radialis

Answer 7

proximal: common flexor origin

distal: base of 2nd metacarpal

innervation: median nerve

action: flex wrist and abduct wrist

Question 8

What type of muscle is Palmaris longus considered as

Answer 8

Vestigial muscle - absent on one or both sides in 15% of the population

Question 9

Palmaris longus

Answer 9

proximal attachment: common flexor origin

distal attachment: palmar aponeurosis

Innervation: median nerve

Action: flexes wrist and tenses palmar aponeurosis

Question 10

Flexor carpi ulnaris

Answer 10

proximal: common flexor origin, olecranon process, posterior shaft of ulna

distal: pisiform, hook of hamate, base of 5th metacarpa;

innervation: ulnar nerve

action: wrist flexion and wrist adduction

Question 11

What bone is formed within the tendon of flexor carpi ulnaris

Answer 11

pisiform ( a sesamoid bone)

Question 12

Flexor digitorum superficialis

Answer 12

proximal attachment: common flexor origin and shaft of radius

distal attachment: middle phalanges of digits 2-5

innervation: median nerve

action: flexes wrist, flex all joints in wrist except distal interphalangeal joints

Question 13

Flexor digitorum profundus proximal attachment

Answer 13

proximal: Interosseous membrane and ulna (does not cross elbow)

distal: distal phalanges of digits 2-5

Innervation: medial half: ulnar nerve
lateral half: median nerve

actions: wrist flexion, flexion of all joints in the wrist including distal interphalangeal joints

Question 14

Flexor pollicis longus

Answer 14

proximal: Interosseous membrane and radius (does not cross elbow)

distal: distal phalanx of the thumb

innervation: median nerve

Actions: only flexes all joint of the thumb

Question 15

Pronator quadratus

Answer 15

proximal: distal surface of ulna

distal: distal surface of radius

innervation: median nerve

actions: forearm pronation

Question 16

The concavity of the carpus due to what bony landmarks (4)

Answer 16

1. Tubercle of the scaphoid
2. Tubercle of the trapezium
3. Pisiform
4. Hook of Hamate

Question 17

What is the flexor retinaculum

Answer 17

a band of connecive tissue that attaches to the bony landmarks that make up the concavity of the carpus