Upper Limb 4 Flashcards
What muscle is highlighted?
Adductor pollicis
What are the heads of the adductor pollicus?
Transverse and oblique head
What is the function of the adductor pollicis?
Adducts the thumb
What is the innervation of the adductor pollicis?
Deep branch of ulnar nerve
What muscles are in the deepest muscle layer of the hand?
Interossei - lie between metacarpal bones
What are the 2 types of interossei?
Palmar - 1-3
Dorsal - 1-4
What is the action of the dorsal interossei?
Abduct the fingers
What is the action of the palmar interossei?
Adduct the fingers
What is the innervation of the dorsal and palmar interossei?
Deep branch of ulnar nerve
Which spinal segment contributes the most to the innervation of the interossei?
T1
What arteries supply blood supply to the hand?
Ulnar and radial arteries
Which artery is the main contributor to the superficial palmar arch?
Ulnar artery
Which artery is the main contributor to the deep palmar arch?
Radial artery
Where is the deep palmar arch formed after?
After the radial artery crosses the anatomical snuff box, passing between 2 heads of 1st dorsal interossei and 2 heads of adductor pollicis
What does the median nerve innervate in the hand?
Majority of thenar eminence muscles apart from deep belly of flexor pollicis brevis, and the 1st and 2nd lumbricals
What nerves supply the muscles of the hand?
Median and ulnar nerve
What segmental fibres of median and ulnar nerves innervate the intrinsic muscles of the hand?
C8-T1
What cord is the ulnar nerve a branch of on the brachial plexus?
Median cord of brachial plexus
How is the axillary nerve tested for motor function?
Abducting the shoulders (deltoid)
How is the musculocutaneous nerve tested for motor function?
Flexing the elbow (bicpes and brachialis)
How is the radial nerve tested for motor function?
Extending wrist (posterior compartment of the forearm)
How is the ulnar nerve tested for motor function?
Spreading fingers (intrinsic muscles of the hand)
How is the median nerve tested for motor function?
Move your thumb towards your nose (abductor pollicis brevis)
What are bony features of the radius and ulna?
Radius tuberosity, styloid process of radius + ulna, olecranon of ulna and proximal + distal radio-ulnar joints
What is the interosseous membrane?
Incomplete fibrous structure - conforming stability to the forearm structure
It is lax enough to allow supination and pronation at radio-ulnar joints
What sits between the ulna and carpal bones?
Articular disc
What does the radius articulate with?
Articular disc and proximal row of carpal bones
What type of fluid is found between the forearm and carpal bones?
Synovial fluid which reduces friction
What does the combined action of the flexor and extensor carpi ulnaris cause?
Ulnar deviation or adduction of the wrist
What muscles are responsible for radial deviation or abduction of the wrist?
Flexor and extensor carpi radialis
What is 1?
Radius
What is 2?
Ulna
Where do the metacarpal bones articulate?
Proximally at the carpo-metacarpal CMC joints and distally at the metacarpophalangeal MP joints
What are the muscles that extend and abduct/ adduct the hand at wrist joint?
Extensor carpi longus
Extensor carpi brevis
Extensor carpi ulnaris
What is the orange muscle on the medial side?
Anconeus
What is the blue muscle?
Extensor carpi radialis longus and brevis
What is the yellow muscle?
Extensor digitorium
What is the green muscle?
Extensor digiti minimi
What is the purple muscle?
Extensor carpi ulnaris
What is the orange muscle on the lateral side?
Brachioradialis
What is the action of the extensor carpi radialis longus an d brevis on wrist joint?
Extension and abduction
Also with help of flexor radialis they can cause radial deviation
What are the muscles in the posterior forearm which extend the medial 4 digits?
Extensor digitorum
Extensor indicis
Extensor digiti minimi
Where does the extensor digitorum arise from?
Common extensor origin on lateral epicondyle of the humerus
Describe the extensor digitorum
The fleshy muscle belly runs distally under extensor retinaculum and divides into 4 tendons for the fingers
What are the muscles which extend or abduct the thumb?
Abductor pollicis longus
Extensor pollicis brevis
Extensor pollicis longus
What is the pink muscle?
Brachioradialis
What is the blue muscle?
Extensor radialis longus and brevis
What is the yellow muscle?
Extensor digitorum
What is the green muscle?
Extensor digiti minimi
What is the purple muscle?
Extensor carpi ulnaris
What is the red muscle?
Abductor pollicis longus
What is the orange muscle?
Extensor pollicis longus
What is the action of the supinator muscle?
Supinates forearm - rotates radius to turn palm anteriorly
What nerve innervates the posterior forearm?
Radial nerve
Where does the radial nerve split into superficial and deep branches?
At cubital fossa
What is the action of the deep branch of the radial nerve?
Main motor nerve of extensors of the forearm
What is the course of the deep branch (posterior interosseous nerve) of the radial nerve?
Runs deep to supinator muscle, eventually piercing it to enter the extensor compartment of the forearm
What is the action of the superficial branch of the radial nerve?
Purely sensory and distributed to skin on the dorsum of the hand
What is the course of the superficial branch of the radial nerve?
As it branches at cubital fossa it runs deep to brachioradialis and enters the hand passing over the anatomical snuff box
What is the arterial supply for the posterior forearm?
Arterial anastomoses
Posterior interosseous artery arising from ulnar artery
Recurrent interosseous artery which branches from posterior interosseous artery
Venous supply follows the same
Where does the cephalic vein lie?
Lateral side as a continuation of the dorsal venous arch running proximally
Where does the basilic vein lie?
Medial side as continuation of the dorsal venous arch
What is the anatomical snuff box?
Shallow depression located on lateral aspect of the wrist when thumb is fully extended
What is the medial border of the anatomical snuff box?
Tendon of extensor pollicis longus
What makes up the lateral border of he anatomical snuff box?
Tendon of extensor pollicis brevis and abductor pollicis longus
What makes up the floor of the anatomical snuff box?
Scaphoid and trapezium carpal bones
What artery can you feel pulsating on floor of anatomical snuff box?
Radial artery
What is the common innervation of the extensor pollicis longus + brevis and adductor pollicis longus?
Posterior interosseous nerve - radial nerve
