Upper Limb 3 Flashcards
What is the function of the anterior compartment of the forearm?
Flexors of the wrist and digits
Also facilitate pronation of the forearm at radio-ulnar joint
What is the common flexor origin for the superficial and intermediate flexors?
Medial epicondyle
What is A?
Flexor carpi radialis
What is B?
Plamaris longus
What is C?
Flexor carpi ulnaris
What is D?
Pronator teres
What is the action of the pronator teres?
Pronator forearm and flexes elbow joint
What muscle does ulnar deviation of the wrist?
Flexor carpi ulnaris
What muscle does radial deviation of the wrist?
Flexor carpi radialis
What nerve supplies the superficial muscles of the anterior forearm?
Median nerve except ulnar nerve supplying the flexor carpi ulnaris muscle
What is the only muscle in the intermediate group of the forearm?
Flexor digitorium superficialis (FDS)
To which digits are the 4 tendons of the FDS attached?
Medial 4 digits
On which phalanx are the tendons of FDS attached to?
Middle phalanx
What is the action of the FDS muscle?
Flexes the wrist, metacarpophalangeal and proximal interphalangeal joints
What nerve innervates the flexor digitorium superficialis?
Median nerve
What is the main action of the brachioradialis muscle?
Weak flexion of the elbow joint
Maximal when forearm in mid-pronated position
Which nerve supplies the brachioradialis muscle?
Radial nerve
What is A?
Flexor pollicus longus
What is B?
Pronator quadratus
What is C?
Flexor digitorium profundus
Describe the FDP
Long, thick muscle that lies deeply in the front of the forearm
Lies more superficially on medial border and back of forearm
What is the main action of FDP on the wrist and fingers?
Flexes wrist joint at carpometacarpal joint and flexes distal interphalangeal joints of digits 2,3,4 and 5
Describe the dual supply of the FDP
Medial part (digits 4 + 5) - ulnar nerve
Lateral part (digits 2 + 3) - median nerve
What is the action of the flexor pollicus longus (FPL)?
Long flexor of the thumb
What innervates the flexor pollicus longus?
Anterior interosseous nerve from median nerve
What is the origin and insertion of the pronator quadratus?
Origin - anterior aspect of ulna
Insertion - radius
What is the innervation of the pronator quadratus?
Anterior interosseous nerve from median nerve
What are the pronator muscles of the anterior forearm?
Pronator teres and pronator quadratus
What is 1?
Radial nerve
What is 2?
Radial artery
What is 3?
Median nerve
What is 4?
Ulnar artery
What is 5?
Ulnar nerve
What is the course of the median nerve in forearm?
Enters the forearm medial to brachial artery
Then passes under FDS muscle and passes down forearm between FDS and FDP
Enters the carpal tunnel inferior to the flexor retinaculum
What muscles does the median nerve not supply in the anterior forearm?
Flexor carpi ulnaris and medial half of flexor digitorium profundus
Describe the course of the ulnar nerve
Passes posterior to medial epicondyle of humerus, then enters forearm by passing between heads of flexor carpi ulnaris muscle
Where does the ulnar nerve lie in relation to the ulnar artery?
Medial and superficial
Where does the brachial artery divide?
At neck of the radius
Describe the course of the ulnar artery
Runs distally with ulnar nerve between FCU and FDP
Then forms the superficial palmar arch after running through the wrist
Describe the course of the radial artery
Initially starts under brachioradialis and runs over pronator teres and flexor pollicus longus lying on distal radius
Forms deep palmar arch
What is the carpal tunnel?
Passageway from forearm to hand, passing deep to flexor retinaculum
What is the flexor retinaculum?
Strong fibrous band which stabilises the concavity of the palmar surface of the carpus and transmits several structures
What carpal bones are attached to flexor retinaculum?
Scaphoid
Lateral side of the trapezium
Pisiform
Medial site of hamate
What are the contents of the carpal tunnel?
4 tendons of flexor digitorium profundus
4 tendons of flexor digitorium superficialis
1 tendon of flexor pollicus longus
Median nerve
Describe carpal tunnel syndrome
Condition where any reduction in space within carpal tunnel can result in weakness and tingling of muscles + skin supplied by median nerve
What is the treatment for carpal tunnel syndrome?
Flexor retinaculum is dissected under local or general anaesthetic and nerve is freed
What is the function of the palmar fascia?
Fibres provide a lattice structure that protects the deep muscles and neurovascular structures of the hand
Which muscle of the forearm is continuous with the fascia of the palm?
Plantaris longus
What are the 5 compartments of the hand from superficial to deep?
Thenar compartment
Hypothenar compartment
Lumbricals and long flexor tendons
Adductor compartment
Interosseous compartment
What do the thenar muscles form?
Fleshy muscle belly - thenar eminence on lateral aspect of the palm
What are 3 muscles of the thenar compartment?
Flexor pollicus brevis
Opponens pollicus
Abductor pollicus brevis
What is A?
Flexor pollicus brevis
What is B?
Abductor pollicus brevis
What is C?
Opponens pollicus
What is the innervation of the thenar muscles?
Median nerve except the deep belly of flexor pollicus brevis which is ulnar nerve
Which nerve segment from brachial plexus serves to provide most of innervation to thenar muscles?
C8
What are the muscles in the hypothenar compartment of the hand?
Abductor digiti minimi
Flexor digiti minimi
Opponens digiti minimi
What nerve innervates the hypothenar muscles?
Deep branch of the ulnar nerve
Which nerve from the brachial plexus serves to provide most of innervation to the hypothenar muscles?
T1
What is A?
Flexor digiti minimi
What is B?
Abductor digiti minimi
What is C?
Oppenens digiti minimi
What is the movement of opposition?
Movement of the thumb or little finger towards the other fingers
Where is the central compartment of the hand muscles?
Lying deep to palmar aponeurosis but between thenar and hypothenar eminence
What muscles are in the central compartment of the hand?
Long flexor tendons - Flexor digitorium superficialis + profundus and flexor pollicus longus
4 lumbricals
Where do the lumbricals arise from?
Medial and lateral aspects of FDP tendon between 1st to 5th metacarpals
What is the function of the lumbricals?
Flex the fingers at metacarpophalangeal joints and extend the interphalangeal joints of 2nd to 5th digits
What are the 2 medial lumbricals innervated by?
Ulnar nerve
What are the 2 lateral lumbricals innervated by?
Median nerve
