B7.018 Forearm, Cubital Fossa and Hand Flashcards
2 compartments in the forearm
anterior (volar)
posterior (dorsal)
separated by the two bones and the interosseous membrane
each has its own deep fascia
anterior forearm compartment
anteromedial
muscles originate from the medial epicondyle and medial epicondyle ridge of humerus
innervated by median and ulnar nerves
posterior forearm compartment
posterolateral
muscles originate from the lateral epicondyle and lateral epicondyle ridge of the humerus
function as extensors and supinators
innervated by radial nerve
structure of forearm muscles
fleshy masses at proximal part of forearm
form tendons as they approach the distal forearm and tendons continue into the wrist, hand, and digits
what is the anterior interosseous nerve
branch of median nerve at distal cubital fossa
what does the anterior interosseous innervate
lateral FDP
flexor pollicis longus
pronator quadratus
(deep anterior forearm muscles)
forearm skin innervation
medial side = medial cutaneous
lateral side = musculocutaneous
hand skin innervation
anterior radial 3.5 fingers/palm = median
posterior radial 3.5 fingers = radial
anterior / posterior ulnar 1.5 finger/palm = ulnar
recurrent branch of median nerve
supplies 3 thenar muscles
comes out of the carpal tunnel woohoo
flexor retinaculum
transverse carpal ligament
dense CT band that bridges between trapezium and pisiform, plus hook of hamate
roof of carpal tunnel
palmar carpal ligament
superficial to flexor retinaculum
rook of Guyon’s canal (ulnar nerve)
what structures make the canal of Guyon
pisiform and hook of the hamate
branches of the brachial artery
branches into ulnar (larger) and radial (smaller) at the head of the radius in the lower cubital fossa region
branches of the ulnar artery
-common interosseous artery divides immediately into: anterior interosseous artery posterior interosseous artery -muscular branches: muscles on medial forearm
superficial palmar arch
continuation of the ulnar artery that anastomoses with the radial artery
deep palmar arch
deep branch of ulnar artery that anastomoses with radial artery
significance of radial artery location
demarcation for the separation of the flexors and extensors of the forearm
runs across floor of anatomical snuff box (pulse)
US DR relationship
Superficial palmar arch is mainly Ulnar artery
Deep palmar arch is mainly Radial artery
borders of anatomical snuff box
top: extensor pollicis longus
bottom: extensor pollicis brevis
contents of anatomical snuff box
radial artery on floor
scaphoid, trapezium, and 1st CMC
deep branch of radial nerve
muscular and articular
injury: inability to extend thumb and MCPs
superficial branch of radial nerve
cutaneous and articular
supplies skin on dorsal side of hand and a number of joints in the hand
function of fibrous digital sheath
anchors flexor tendons to each phalanx with synovial sheath in between
annular
all the way around
