L4 + L5: Forearm and Hand Muscles

Question 1

Brachioradialis

Answer 1

Attachment:
Originates from the lateral epicondyle of the humerus and inserts into the distal radius.

Function:
Responsible for forearm flexion,

Nerve Supply:
Innervated by the radial nerve (C5-C6).

Blood Supply:
radial artery.

Question 2

Flexor Carpi Radialis

Answer 2

Attachment:
Originates from the medial epicondyle of the humerus and inserts into the base of the second metacarpal.

Function:
wrist flexion and radial deviation.

Nerve Supply:
Innervated by the median nerve (C6-C7).

Question 3

Palmaris Longus

Answer 3

Attachment:
Originates from the medial epicondyle of the humerus and inserts into the palmar aponeurosis.

Function:
Assists in wrist flexion and tenses the palmar aponeurosis.

Nerve Supply:
Innervated by the median nerve (C6-C7).

Question 4

Flexor Carpi Ulnaris

Answer 4

Attachment:
Originates from the medial epicondyle of the humerus and the posterior border of the ulna, inserting into the pisiform bone and the base of the fifth metacarpal.

Function:
wrist flexion and ulnar deviation.

Nerve Supply:
Innervated by the ulnar nerve (C7-C8).

Question 5

Pronator Teres

Answer 5

Attachment:
Originates from the medial epicondyle of the humerus and the coronoid process of the ulna, inserting into the radius.

Function:
Pronates the forearm and assists in elbow flexion.

Nerve Supply:
Innervated by the median nerve (C6-C7).

Question 6

Pronator Quadratus

Answer 6

Attachment:
Originates from the distal part of the anterior ulna and inserts into the distal part of the anterior radius.

Function:
pronation of the forearm.

Nerve Supply:
Innervated by the median nerve (C6-C7).

Question 7

Flexor Digitorum Superficialis

Answer 7

Attachment:
Originates from the medial epicondyle of the humerus, the ulna, and the radius, inserting into the middle phalanges of the fingers.

Function:
Flexes the middle phalanges of the fingers.

Nerve Supply:
Innervated by the median nerve (C7-T1).

Question 8

Flexor Digitorum Profundus

Answer 8

Attachment:
Originates from the ulna and interosseous membrane, inserting into the distal phalanges of the fingers.

Function:
Flexes the distal phalanges of the fingers.

Nerve Supply:
Innervated by the median nerve (lateral) and the ulnar nerve (C7-T1) (medial)

Question 9

Flexor Pollicis Longus

Answer 9

Attachment:
Originates from the radius and interosseous membrane, inserting into the distal phalanx of the thumb.

Function:
Flexes the distal phalanx of the thumb.

Nerve Supply:
median nerve (C8-T1).

Question 10

Extensor Carpi Radialis Longus (blue)

Answer 10

Attachment:
Originates from the lateral supracondylar ridge of the humerus and inserts into the base of the second metacarpal.

Function:
wrist extension and radial deviation.

Nerve Supply:
Innervated by the radial nerve (C7-C8).

Question 11

Extensor Carpi Radialis Brevis (blue)

Answer 11

Attachment:
Originates from the lateral epicondyle of the humerus and inserts into the base of the third metacarpal.

Function:
wrist extension and radial deviation.

Nerve Supply:
Innervated by the radial nerve (C5-C8).

Question 12

Extensor Carpi Ulnaris (purple)

Answer 12

Attachment:
Originates from the lateral epicondyle of the humerus and the posterior border of the ulna, inserting into the base of the fifth metacarpal.

Function:
wrist extension and ulnar deviation.

Nerve Supply:
Innervated by the radial nerve (C7-C8).

Question 13

Extensor Digitorum

Answer 13

Attachment:
Originates from the lateral epicondyle of the humerus and the anterior shaft of the ulna, inserting into the middle and distal phalanges of the fingers.

Function:
Extends the fingers at the metacarpophalangeal and interphalangeal joints.

Nerve Supply:
radial nerve (C7-C8).

Question 14

Extensor Digiti Minimi

Answer 14

Attachment:
Originates from the lateral epicondyle of the humerus and the posterior surface of the ulna, inserting into the dorsal aspect of the proximal phalanx of the little finger.

Function:
Extends the little finger at the metacarpophalangeal and interphalangeal joints.

Nerve Supply:
radial nerve (C7-C8).

Question 15

Extensor Indicis

Answer 15

Attachment:
Originates from the posterior surface of the ulna, inserting into the extensor expansion of the index finger.

Function:
Extends the index finger at the metacarpophalangeal and interphalangeal joints.

Nerve Supply:
radial nerve (C7-C8).

Question 16

Extensor Pollicis Longus

Answer 16

Attachment:
Originates from the posterior surface of the ulna and interosseous membrane, inserting into the distal phalanx of the thumb.

Function:
Extends the thumb at the metacarpophalangeal and interphalangeal joints.

Nerve Supply:
radial nerve

Question 17

Extensor Pollicis Brevis

Answer 17

Attachment:
Originates from the radius and the interosseous membrane, inserting into the base of the proximal phalanx of the thumb.

Function:
Extends the thumb at the metacarpophalangeal joint.

Nerve Supply:
radial nerve (C7-C8).

Question 18

Abductor Pollicis Longus

Answer 18

Attachment:
Originates from the posterior surface of the ulna and radius and inserts into the base of the first metacarpal bone and the trapezium.

Function:
Abducts and extends the thumb at the carpometacarpal joint.

Nerve Supply:
radial nerve (C7-C8).

Question 19

Brachialis

Answer 19

Attachment:
Originates from the anterior surface of the humerus, specifically the distal half of the humerus, and inserts into the ulnar tuberosity.

Function:
The brachialis muscle is the primary flexor of the elbow joint, responsible for flexing the forearm.

Nerve Supply:
Innervated by the musculocutaneous nerve (C5-C6) and the radial nerve.

Blood Supply:
brachial artery.