Anatomy dissection 12

Question 1

What are the muscles of the anterior compartment of the arm ?

Answer 1

• Biceps brachii - long and short head
• Coracobrachialis
• Brachialis

Question 2

What is the anterior compartment of the arm innervated by ?

Answer 2

The musculocutnaeous nerve

Question 3

What are the attachments of the biceps brachii muscles ?

Answer 3

• Long head attaches to supraglenoid tubercle of scapula
• Short head attaches to coracoid process of scapula

Biceps tendon attaches to the radial tuberosity

Question 4

Describe the biceps deep tendon reflex and its use

Answer 4

• Hammer hit off biceps tendon which will bring about flexion of the forearm at the elbow
• Positive test shows C5 & 6 (musculocutaneous nerve) are working and the central connections of the spinal cord above are also working

Question 5

Describe the position of the muscles of the anterior compartment of the arm to each other

Answer 5

• The biceps brachii are the most anterior of the muscles
• The coracobrachialis is found deep to the biceps and medial to the brachialis
• Brachialis is deep to biceps brachii and lateral to coracobrachialis

Question 6

What is a good mnemonic to remember the anterior compartment muscles of the arm ?

Answer 6

BBC

Question 7

What are the attachments of the coracobrachialis muscle ?

Answer 7

• Proximally - Coracoid process of the scapula
• Distally - humerus

Question 8

What are the attachments of the brachialis muscle ?

Answer 8

• Proximally - humerus
• Distally - coronoid process of the ulna

Question 9

What is the function of the coracobrachialis ?

Answer 9

Flexion of the arm at the shoulder

Question 10

What is the function of the brachialis muscle ?

Answer 10

Flexion at the elbow.

Question 11

Describe the innervation of the anterior compartment muscles of the forearm

Answer 11

• All median nerve
• Except - Flexor carpi ulnaris and medial part (to digits 4 & 5) of flexor digitorum profundus which is supplied by ulnar nerve

Question 12

There are 3 layers to the anterior compartment of the forearm - what are they ?

Answer 12

Superficial, intermediate and deep

Question 13

What are the superficial muscles of the anterior compartment of the forearm ?

Answer 13

• Pronator teres
• Palmaris longus
• Flexor carpi radialis
• Flexor carpi ulnaris

Question 14

What is the muscle of the intermediate part of the anterior compartment of the forearm?

Answer 14

Flexor digitorum superficialis

Question 15

What are the muscles of the deep part of the anterior compartment of the forearm ?

Answer 15

• Flexor digitorum profundus
• Flexor pollicis longus
• Pronator quadratus

Question 16

What is a useful mnemonic for remembering the superficial and intermediate muscles of the anterior forearm?

Answer 16

• *Anterior forearm muscles: superficial group“P**imps F*ck Prostitutes For Fun”:
• *P**ronator teres
• *F**lexor carpi radialis
• *P**almaris longous
• *F**lexor carpi ulnaris
• *F**lexor digitorum superficialis

Question 17

When the tendons of the muscles of the anterior forearm cross the wrist what are they held in place by ?

Answer 17

Flexor retinaculum

Question 18

What is the general overall function of the anterior forearm muscles ?

Answer 18

• Perform flexion at the wrist and fingers
• And pronation.

Question 19

What is the distal attachment of the flexor digitorum superficialis ?

Answer 19

The muscle splits into four tendons at the wrist, which attaches to the middle phalanges of the four fingers

Question 20

What are the functions of the superifical anterior forearm muscles ?

Answer 20

• Flexor carpi ulnaris - adduction and flexion at the wrist
• Flexor carpi radialis - abduction and flexion at the wrist
• Palmaris longus - flexion at the wrist

Pronator teres - pronation of the forearm

Question 21

What is the function of the intermediate muscle of the anterior forearm ?

Answer 21

Flexor digitorum superficialis - Flexes the metacarpophalangeal joints and proximal interphalangeal joints at the 4 fingers, and flexes at the wrist.

Question 22

What are the distal attachments of the flexor digitorum profundus and its function ?

Answer 22

Distally it splits into 4 tendons and attaches to the distal phalanges of the 4 fingers

Function - flex the distal interphalangeal joints of the fingers. It also flexes at metacarpophalangeal joints and at the wrist.

Question 23

What is the distal attachment of the flexor pollicus longus and its function ?

Answer 23

Distally attaches to the base of the distal phalanx of the thumb

Function - Flexes the interphalangeal joint and metacarpophalangeal joint of the thumb.

Question 24

What is the distal attachment of the pronator quadratus and its function ?

Answer 24

Distall attahes to the anterior surface of the radius

Function - pronates the forearm

Question 25

What are the borders of the cubital fossa ?

Answer 25

• Lateral - brachioradialis muscle
• Medial - Pronator teres
• Superior - An imaginary line between the epicondyles of the humerus

Question 26

What are the contents of the cubital fossa ?

Answer 26

• Superficial contents - Median cubital vein, cephalic vein and basilic vein
• Deep contents - Median nerve, brachial artery and radial nerve

Question 27

Where does the ulnar nerve cross the elbow joint ?

Answer 27

Crosses it at the posterior surface of the medial epichondyle (can be palpated and readily injured) ‘‘funny bone site’’