Forearm Flashcards
Describe deep fascia of forearm and the formation of extensor retinacula.
deep fascia of forearm (antibrachial fascia) is a continuation of brachial fascia from the arm. Distally the antebrachial fascia will thicken and form the flexor and extensor retinacula.
Where does the extensor retinaculum extend?
extends across the posterior radiocarpal joint from the anterior border of the distal radius to the triquetrum and pisiform bones
Where is the flexor retinaculum (transverse carpal ligament)?
attached medially to pisiform and hook of hamate, and laterally to the trapezium and scaphoid bones of wrist
forms carpal tunnel and canal of Guyon
What happens if there is edema in the carpal area?
median nerve will be injured because it is the softest
Name the superficial muscles of the anterior forearm.
Where do they come off of?
pronator teres flexor carpi radialis palmaris longus flexor digitorum superficialis flexor carpi ulnaris
come off medial epicondyle
Which muscle is involved in the curling over of fingers tips, distal phlanges to bend?
flexor digitorum profundus (deep branch of median nerve)
Name the deep muscles of the anterior forearm.
flexor digitorum profundus
flexor pollicis longus
pronator quadratus
What are the superficial muscles of the posterior forearm?
Brachioradialis, anconeous, extensor carpi radialis longus (can influence elbow because cross it) extensor carpi radialis brevis extensor digitorum extensor digiti minimi extensor carpi ulnaris
What is the most powerful extensor of the elbow?
triceps
Name the deep forearm extensors (5)
supinator ABductor pollicis longus extensor pollicis longus extensor pollicis brevis extensor indicis
Describe the anatomical snuff box: How is it formed laterally and medially? What artery runs through floor? What runs across roof? What can be palpated distally? Which bones form the floor?
formed by abductor pollicis longus and extensor pollicis brevis tendons laterally
extensor pollicis longus tendon medially
-Radial artery runs through floor
Branches of superficial radial nerve run across roof
-Styloid process of radius can be palpated distally
-Scaphoid and trapezium bones form floor
Where does the radial artery extend?
Extends from the neck of the radius to the medial side of the styloid process. It lies deep to the brachioradialis muscle, but becomes superficial in the distal 1/3 of the arm. site of radial pulse.
Where does the ulnar artery extend?
extends from the neck of the radius to the flexor retinaculum on the medial edge of the wrist. Runs deep to superficial flexors in forearm. Runs with the ulnar n. in the distal half of the forearm and enters the hand via the canal of Guyon with the ulnar n.
Can be palpated just lateral to the tendon of FCU.
Gives of common interosseous artery in cubital fossa.
Describe the common interosseous artery.
Is a short trunk off ulnar artery extending laterally. Quickly divides into 2 branches : anterior interosseous and posterior interosseous
Describe the pathways of the anterior and posterior interosseouses.
divisions of common interosseous artery
anterior interosseous - travels down forearm superficial to the interosseous membrane. pierces the interosseous membrane distally to anastamose with the posterior interossesous artery. continues under the pronator quadratus muscle to the palmar carpal network
posterior interosseous - passes immediately deep to the interosseous membrane to supply the posterior forearm between the superficial and deep groups of muscles
