Upper Limb 4 Flashcards
What is the action of the extensor carpi radialis longus and brevis on the wrist joint
They both extend and abduct the wrist joint
Muscles that extend and abduct or adduct the hand at the wrist joint
- extensor carpi radialis longus
- extensor carpi radialis brevis
- extensor carpi ulnaris
Where does the extensor digitorum originate
The common extensor origin - lateral epicondyle
Which muscles extend or abduct the thumb
- abductor pollicis longus
- extensor pollicis brevis
- extensor pollicis brevis
Which nerve innervates all the muscles of the posterior compartment of the forearm
Radial nerve
Action of the brachioradialis
Flexion of the elbow
Which muscles originate from the lateral epicondyle
- extensor carpi radialis brevis
- extensor carpi ulnaris
- extensor digitorum
- extensor digiti mimimi
- aconeus muscle
Name the muscles that extend the medial 4 digits
- extensor digitorum
- extensor indicis
- extensor digiti minimi
What is the nerve supply to the supinator
Radial (deep branch)
Where does the radial nerve divide and what does it divide into
Superficial and deep branches in the cubital fossa
What is the other name for the deep branch of the radial nerve
Posterior interosseous nerve
Where is the palmaris longus in relation to the flexor carpi radialis and flexor carpi ulnaris
In between
What is the anatomical snuffbox
A shallow depression on the lateral aspect of the wrist when the thumb is fully extended
Which artery lies on the floor of the anatomical snuff box
Radial
What is the medial border of the anatomical snuffbox
Extensor pollicis longus TENDON
Which muscles form the lateral border of the anatomical snuffbox
Extensor pollicis brevis and abductor pollicis longus TENDONS
What forms the floor of the anatomical snuffbox
The carpal bones; scaphoid and trapezium
Which nerve innervates the extensor pollicis longus, extensor pollicis brevis and abductor pollicis longus
The radial nerve
Contents of the anatomical snuff box
The radial artery and cephalic vein
What is the main action of the extensor pollicis longus
Extension of the thumb at the interpharyngeal joint
What is the main action of the extensor pollicis brevis
Extends the proximal phalanx of the thumb at the metacapopharyngeal joint
What is the main action of the abductor pollicis longus
Abducts thumb and extends it at carpometacarpal joint
Where is the supinator muscle in relation to the other muscles of the posterior forearm
Supinator is deep to all
During examination of the hand, where is the best area to test sensation for the radial nerve
The thumb and index finger web space
Where is best to test sensation of the ulnar nerve
Hypothenar eminence
Where is the best place to assess sensation of the median nerve
Thenar eminence
Name the 2 projections on the proximal ulna
- the olecranon - posterior
- the coronoid process - anterior
Main action of the pectoralis minor
Stabilise scapula by drawing inferiorly and anteriorly against thoracic wall
Insertion of the pectoralis major
Crest of the greater tubercle of the humerus
Action of the pectoralis major muscle
Adduction and medial rotation of the humerus
Or can flex the humerus with the clavicular head or extend from the flexed position with the sternocostal head
Effect of injury to the long thoracic nerve
Winged scapula due to failure of the serratus anterior muscle. The arm cannot be abducted above the horizontal position because the serratus anterior cannot rotate the glenoid cavity superiorly
What is the action when the superior and inferior fibres of the trapezius work together
Rotate the scapula on the thoracic wall
Which muscles are used to raise the trunk to the arm, e.g. During chin ups or climbing
Latissmus dorsi and pectoralis major
Actions of the rhomboid muscles
Retraction of the scapula and rotation to depress the glenoid cavity
Action of the teres major
Adducts and medially rotates arm
- from the inferior lateral border of the posterior scapular to the lesser tubercle of the humerus
Effect of axillary nerve damage
How might the damage occur
Atrophy of the deltoid muscle, loss of sensation may occur over the lateral side of the proximal part of the arm.
Surgical neck of humerus fracture
Structures supplied by the musculocutaneous nerve
Anterior arm - biceps brachii, Coracobrachialis and brachialis
Sensory innervation lateral forarm
Structures supplied by auxiliary nerve
Glenohumeral joint, deltoid, teres minor, skin of superolateral forearm (deltoid)
Structures supplied by the radial nerve
All posterior compartment of arm and forearm - triceps, extensor carpi radialis, extensor carpi ulnaris, extensor digitorum…
Skin of the posterior and inferiolateral forarm and dorsal hand lateral to axial line of digit 4
Structures supplied by ulnar nerve
Half of the flexor digitorum profundus, flexor Carpi ulnaris and most intrinsic muscles of hand and skin of hand medial to digit 4
Structures supplied by median nerve
Muscles of anterior forearm compartment (except flexor carpi ulnaris and half of flexor digitorum profundus); 5 intrinsic muscles in thenar half of Palm and palmar skin
