Anatomy of the forearm Flashcards
Name the skeletal components of the forearm
Radius - head, radial tuberosity, styloid process of the radius
Ulnar - Olecranon, trochlea notch, ulna notch, styloid process the ulna
What is between the radius and ulnar?
Interosseous membrane
What type of joint is the elbow joint?
Synovial hinge joint
What movement does the forearm do?
Flexion/extension
What does the head of the radius articulate with?
Capitulum
What type of joint is the radioulnar joint?
Pivot joint
What movement does the radioulnar joint do?
Supination/pronation
What is the function of ligaments?
Stabilise/strengthen the joint
List some ligaments
Radial collateral ligament
Ulnar collateral ligament
Annular ligament
What is the cubital fossa?
Triangle region over the anterior elbow
Where is the cubital fossa located?
Lateral epicondyle
Medial epicondyle
Point where pronator teres crosses with brachioradialis
Which tendon passes through the cubital fossa?
Biceps tendon
Which nerves pass through the cubital fossa
Lateral cutaneous nerve to forearm
Median nerve
What is the median cubital vein important for?
Venepuncture
Where is the median cubital vein?
Between the basilic and cephalic vein
Name the two compartments of the forearm
Flexor compartments
Extensor compartments
What do the long tendons of the forearm enter?
The hand
Where do the superficial and intermediate muscles of the hand originate?
From common flexor origin
What is golfers elbow?
Epicondylitis at CFO (tendon inflammation due to overuse/excessive gripping)
Name the superficial muscles of the anterior forearm
Pronator teres
Flexor carpi radialis
Palmaris longus
Flexor carpi ulnaris
Where is the common flexor origin?
Medial epicondyle
Name the intermediate muscles of the forearm
Flexor digitorum superficialis
Name the deep muscles of the anterior forearm
Flexor digitorum profundus
Pronator quadratus
Flexor pollicis longus
Where is the extensor compartment of the forearm?
Posterior forearm
List the superficial muscles of the posterior forearm
Extensor carpi radialis longs/brevis
Extensor digitorum
Extensor digiti minimi
Extensor carpi ulnaris
What is tennis elbow?
Epicondylitis at CEO (tendon inflammation due to overuse/forceful extension)
What does anconeus do?
stabilises elbow
What does brachioradialis ?
Flexor when half protonated
List the deep muscles of the posterior forearm
Supinator Abductor pollicis longus Extensor pollicis brevis Extensor pollicis longus Extensor indicis
Which 3 muscles form the anatomical snuffbox?
Abductor pollicis longus
Extensor pollicis brevis
Extensor pollicis longus
Which muscles perform wrist abduction and adduction?
Carpi muscles
Which muscles perform wrist abduction?
- Flexor carpi radialis
- Extensor carpi radialis (longus + brevis)
Which muscles perform wrist adduction?
- Flexor carpi ulnaris
- Extensor carpi ulnaris
What do the deep muscles of the posterior forearm do?
Together muscles splint the wrist to allow fine movements of the hand
List the muscles involved in supination
Biceps brachii
Supinator
List the muscles involved in pronation
Pronator teres
Pronator quadratus
Describe the movement of the radius and ulna during pronation
Radius rotates over the ulna
What is the carpal tunnel?
Tunnel for flexor tendons to digits and median nerve
What is the function of the flexor retinaculum?
Prevents bowing of tendons
What does the carpal tunnel contain?
Median nerve
Flexor policis longus
Flexor digitorum superficialis
Flexor digitorum superficialis
What is carpal tunnel syndrome?
– median nerve compression
Due to increased pressure in carpal tunnel – associated with trauma, obesity, pregnancy
What is the function of the flexor retinaculum
- Prevents bowing of tendons
- Separates tendons into compartments
Where does the extensor digitorum insert?
Into middle and distal phalanx
Where does the flexor digitorum insert?
Into distal phalanx
Where does the flexor digitorum superficialis insert?
Into middle phalanx
Where does the brachial artery divide?
Radial artery
Ulnar artery
Which muscle overlies radial artery?
Brachioradialis
Which muscle overlies ulnar artery
- Under flexor carpi ulnaris
- Gives off common interosseous
Describe the nerve supply to the forearm
Musculocutaneous nerve
Radial nerve
Median nerve
Ulnar nerve
Describe the location of the median nerve
Lies mid forearm between FDS and FDP
Branch - Anterior interosseous nerve
(to deep flexor muscles)
Passes through carpal tunnel
What is the function of the median nerve?
Motor supply to anterior compartment except FCU/medial part of FDP
Sensory supply to lateral palm + d1, d2, d3, ½ d4
What is the function of the ulnar nerve?
Motor supply to FCU and medial part FDP
Sensory supply to medial hand including ½ d4 + d5
What is the clinical significance of the ulnar nerve?
Cubital tunnel syndrome
Give the location of the radial nerve
Enters forearm on lateral side under brachioradialis
Name and describe the branches of the radial nerve
Superficial branch (sensory) Under brachioradialis Winds round to dorsum of hand
Deep branch - posterior interosseous nerve (motor) Passes through supinator muscle Enters extensor compartment
What is the function of the radial nerve?
Deep branch supplies posterior compartment
Superficial branch supplies lat dorsum hand
Give the clinical significance of the radial nerve
Wrist drop