Flexor and Pronator Muscles of the Forearm

Question 1

Anterior vs. Posterior Forearm Compartment separated by (3) structures

Answer 1

Separation:
Lateral Intermuscular Septum: Extends from the radius to deep fascia.
Interosseous Membrane: Links adjacent borders of the radius and ulna.
Deep Fascia: Attaches to the posterior border of the ulna.

Question 2

Flexor Carpi Ulnaris (Superficial Layer)
origin
insertion
function

Answer 2

Origin: Olecranon, posterior border of ulna, medial epicondyle of humerus.
Insertion: Pisiform bone, hamate bone, base of metacarpal V.
Function: Wrist flexion, wrist adduction.

Question 3

Palmaris Longus (Superficial Layer)
origin
insertion
function

Answer 3

Origin: Medial epicondyle of humerus.
Insertion: Flexor retinaculum, palmar aponeurosis.
Function: Accessory wrist flexion, tenses the skin of the palm during gripping.

Question 4

Flexor Carpi Radialis (Superficial Layer)
origin
insertion
function

Answer 4

Origin: Medial epicondyle of humerus.
Insertion: Anterior bases of metacarpals II and III.
Function: Wrist flexion, wrist abduction.

Question 5

Pronator Teres (Superficial Layer)
origin
insertion
function

Answer 5

Origin: Medial epicondyle of humerus, ulnar coronoid process.
Insertion: Lateral surface of the radius (midshaft).
Function: Pronation of the forearm.

Question 6

Flexor Digitorum Superficialis (Intermediate Layer)
origin
insertion
function

Answer 6

Origin: Medial epicondyle of humerus, coronoid process of ulna, oblique line of radius.
Insertion: Middle phalanges of fingers II-V.
Function: Flexion of the metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints.

Question 7

Flexor Digitorum Profundus (Deep Layer)
origin
insertion
function

Answer 7

Origin: Anterior surface of ulna, interosseous membrane.
Insertion: Distal phalanges of fingers II-V.
Function: Flexion of MCP, PIP, and distal interphalangeal (DIP) joints.

Question 8

Flexor Pollicis Longus (Deep Layer)
origin
insertion
function

Answer 8

Origin: Anterior surface of radius, interosseous membrane.
Insertion: Base of distal phalanx of thumb.
Function: Flexion of the thumb.

Question 9

Pronator Quadratus (Deep Layer)
origin
insertion
function

Answer 9

Origin: Distal ulna (anterior surface).
Insertion: Distal radius (anterior surface).
Function: Pronation of the forearm.