9 Muscles (Anterior Antebrachium)

Question 1

How many muscles are in the anterior antebrachium, and what are their classifications?

Answer 1

Compartment: 8 muscles total
Superficial: 4
Intermediate: 1
Deep: 3

Question 2

What are the muscles of the anterior antebrachium (superficial compartment)?

Answer 2

Pronator teres
Flexor carpi radialis
Palmaris longus (in most people)
Flexor carpi ulnaris

Question 3

What is the muscle in the anterior antebrachium (intermediate compartment)?

Answer 3

Flexor digitorum superficialis

Question 4

What are the muscles of the anterior antebrachium (deep compartment)?

Answer 4

Flexor digitorum profundus
Flexor pollicis longus
Pronator quadratuS

Question 5

Practice an oral presentation of the superficial compartment of the anterior antebrachium muscles

Answer 5

Compartment:
there are 4 muscles in the superficial layer of the anterior antebrachium compartment.
The pronator teres, the flexor carpi radialis, the palmaris longus (in most people), and the flexor carpi ulnaris.

Function: the function of the superficial layer of the anterior antebrachium muscles are the flexion of the wrist joint, the pronation of the forearm, and radial and ulnar deviation.

PRONATOR TERES:
Location: crosses the elbow joint from the medial / ulna side and runs diagonally across the anterior forearm to attach to the radius
Structure: two headed muscle (ulnar head and humeral head)
PA:
Humeral head:CFO (medial epicondyle of the humerus)
Ulnar head: coronoid process of ulna
DA: lateral surface of the radius, in the middle third of the shaft
NS: median nerve (C6-7)
Action: pronation of the forearm

FLEXOR CARPI RADIALIS:
PA: CFO (medial epicondyle of the humerus)
DA: base of 2nd MC
NS: median nerve (C6-7)
Action: flexion of the wrist, radial deviation

PALMARIS LONGUS:
PA: CFO (medial epicondyle of the humerus)
DA: palmar aponeurosis, flexor retinaculum (C7-8)
NS: median nerve
Action: flexion of the wrist, tenses palmar aponeurosis

FLEXOR CARPI ULNARIS:
Structure: two headed muscle (humeral head and ulnar head)
PA:
Humeral head: CFO (medial epicondyle of the humerus),
Ulnar head: olecranon process of the ulna
DA: pisiform and hook of the hamate
NS: ulnar nerve (C7-8)
Action: flexion of the wrist, ulnar deviation

Question 6

Practice an oral presentation of the intermediate layer of the anterior antebrachium compartment

Answer 6

Only one muscle in the intermediate layer of the anterior antebrachium

Flexor DIgitorum Superficialis

Structure: two headed muscle (humeroulnar head and radial head), splits into 4 tendons that run through the carpal tunnel to enter the hand

PA:
Humeroulnar head: CFO (medial epicondyle of the humerus) and coronoid process of the ulna
Radial head: proximal half of the anterior radius
DA: shafts of the middle phalanges on digits 2-5
NS: median nerve (C7-T1)
Actions: flexion of the wrist, flexion of the middle phalanges on digits 2-5, producing flexion at the proximal interphalangeal joints and distal interphalangeal joints

Question 7

Practice an oral presentation of the deep layer of the anterior antebrachium muscles

Answer 7

There are 3 muscles in the deep layer of the anterior antebrachium: the flexor digitorum profundus, the flexor pollicis longus, and the pronator quadratus.

The functions of the deep layer of the anterior antebrachium muscles are flexion of the wrist and fingers, flexion of the thumb, and pronation of the forearm

FLEXOR DIGITORUM PROFUNDUS:
Location: runs deep to the flexor digitorum superficialis of the intermediate later. splits into 4 tendons that run through the carpal tunnel into the hand

PA: proximal third of anterior ulna and adjacent interosseous membrane
DA: distal phalanges of digits 2-5
NS:
medial half: ulnar nerve (C8-T1)
lateral half: median nerve (anterior interosseous branch) (C8-T1)
Action: flexion of the wrist, flexion of the distal interphalangeal joints

FLEXOR POLLICIS LONGUS:
PA: distal anterior radius and adjacent interosseous membrane
DA: base of the distal phalange of the thumb (digit 1)
NS: median nerve (anterior interosseous branch) (C8-T1)
Action: flexion of the thumb

PRONATOR QUADRATUS:
PA: distal quarter of anterior ulna
DA: distal quarter of anterior radius
NS: median nerve (anterior interosseous branch) (C8-T1)
Action: stabilises the connection between the radius and ulna distally, pronates the forearm

Question 8

Which muscles have a proximal attachment at the CFO (common flexor origin)?

Answer 8

There are 5 muscles that have a proximal attchment at the common flexor origin (medial epicondyle of the humerus).

All 4 muscles of the superficial layer of the anterior antebrachium, and the muscle of the intermediate antebrachium.

Superficial layer:
Pronator teres (humeral head)
Flexor Carpi Radialis
Palmaris Longus
Flexor Carpi Ulnaris (humeral head)

Intermediate layer:
Flexor Digitorum Superficialis (humeral head)

Question 9

How many muscles in the anterior antebrachium have two heads?

Answer 9

There are 3 two headed muscles in the anterior antebrachium (2 in the superficial layer and 1 in the intermediate layer)

Pronator teres (humeral head: CFO and ulnar head: coronoid process)

Flexor Carpi Ulnaris (humeral head: CFO and ulnar head: olecranon process)

Flexor Digitorum Superficialis (humeroulnar head: CFO and coronoid process and radial head: proximal anterior radius)

Question 10

Which muscles in the anterior antebrachium compartment are innervated by the median nerve, and which by the ulnar nerve?

Answer 10

The median nerve innervates all muscles in the anterior antebrachium compartment EXCEPT the Flexor Carpi Ulnaris, and the medial half of the Flexor Digitorum Profundus