Forearm

Question 0

Joints

Answer 0

• Elbow joint = synovial hinge
• Proximal radioulnar joint = pivot joint => Radius pivots about the ulna during pronation (held in place by annular ligament)
• Distal radioulnar joint = synovial pivot

Question 1

Interosseous membrane

Answer 1

Unites radius and ulna.
Attachment for muscles.
Fibres pass predominantly inferiorly from radius to ulna.
Transfers force from radius -ulna- humerus- shoulder- clavicle- sternum

Question 2

Pronation

Answer 2

Rotation of radius on capitulum of humerus and enclosed by annular ligament.
Produced by the pronator quadratus and pronator teres.
Innervation by median nerve.

Question 3

Supination

Answer 3

Produced by the supinator and biceps brachii.

Innervation by musculocutaneous and radial nerves.

Question 4

Elbow joint

Answer 4

Synovial hinge joint
Articular surfaces covered with hyaline cartilage
Movements = flexion, extension

Question 5

Stability of elbow joint

Answer 5

Radial collateral joint

Ulnar collateral joint

Question 6

Medial (ulnar) collateral ligament

Answer 6

• Medial epicondyle of humerus to coronoid process and olecranon of ulna.
• Triangular ligament with anterior, posterior and oblique bands.

Question 7

Lateral (radial) collateral ligament

Answer 7

• Lateral epicondyle of humerus to radial notch of ulna and annular ligament; capitulum of humerus to head of radius.
• Is weaker than ulnar collateral ligament but provides posterolateral stability.

Question 8

Anterior forearm muscles

Answer 8

• Superficial layer:
Common flexor origin = medial epicondyle of humerus
• Flexors, pronators
• Mainly innervated by median nerve

Question 9

Blood supply

Answer 9

• Brachial artery
• Ulnar artery
• Radial artery

Question 10

Venous drainage

Answer 10

SUPERFICIAL: 
• Cephalic vein – lateral 
• Median vein – middle 
• Basilic vein - medial 
DEEP: 
• Radial veins 
• Ulnar veins

Question 11

Lymphatics

Answer 11

• Superficial lymphatic vessels follow superficial veins
• Deep lymphatic vessels follow deep veins
• All drains into AXILLARY LYMPH NODES

Question 12

Important structures lying in front of the wrist

Answer 12

Lateral - medial 
• Radial artery 
• Tendon of flexor carpi radialis 
• Tendon of palmaris longus (if present) 
• Tendons of flexor digitorum superficialis 
• Tendon of flexor carpi ulnaris 
• Ulnar artery 
• Ulnar nerve