Unit 15: Posterior Forearm and Hand Flashcards
What is the anatomical snuff box?
edges are tendons of muscles related to the thumb
- tendon of abductor pollicis longus and tendon of extensor pollicis brevis
- tendon of extensor pollicis longus
What muscles are in the superficial region of the posterior portion of the arm? Where do these muscles take their origin? What innervates these muscles?
brachioradialis muscle, extensor carpi radialis longus muscle, extensor carpi radialis brevis muscle, extensor digitorum muscle,extensor digiti minimi muscle, extensor carpi ulnaris muscle, anconeus muscle….
- all take partial origin from a common tendon from the lateral
epicondyle or the supracondylar line above it - all are innervated by the radial nerve and its branches
From where does the brachioradialis muscle originate? Where does it insert? What is its action? What innervates this muscle?
a. origin - from lateral supracondylar ridge
b. inserts - on distal radius above styloid process
c. flexes forearm at elbow
d. innervated by the main trunk of the radial nerve
Where is the origin of the extensor carpi radialis longus? Where does it insert? What innervates this muscle?
a. origin - from lateral supracondylar ridge
b. inserts - on base of second metacarpal
c. passes through the second compartment under extensor
retinaculum
d. innervated by the main trunk of the radial nerve
Where is the origin of the extensor carpi radialis brevis? Where does this muscle insert? What nerve innervates this muscle?
a. origin - from lateral epicondyle
b. inserts - on base of third metacarpal
c. passes through the second compartment under extensor
retinaculum
d. innervated by the deep branch of radial nerve
Where is the origin of the extensor digitorum? Where does this muscle insert? What nerve innervates this muscle?
a. origin - from lateral epicondyle
b. inserts - as extensor hood to middle and distal phalanges of
four fingers
c. passes through the fourth compartment under extensor
retinaculum
d. innervated by the posterior interosseous nerve
Where is the origin of the extensor digiti minimi muscle? Where is the insertion? What nerve innervates this musle?
a. origin - from lateral epicondyle
b. inserts - on extensor hood of little finger
c. passes through the fifth compartment under extensor
retinaculum
d. innervated by the posterior interosseous nerve
Where is the origin of the extensor carpi ulnaris? Where does this muscle insert? What nerve innervates this muscle?
a. origin - from lateral epicondyle
b. inserts on base of fifth metacarpal
c. passes through the sixth compartment under extensor
retinaculum
d. innervated by the posterior interosseous nerve
Where is the origin of the aconeus muscle? Where does it insert? What innervates this muscle?
a. origin - from lateral epicondyle
b. inserts - on upper one-fourth of ulna
c. innervated from main trunk of the radial nerve
What are the deep muscles of the posterior forearm?
supinator, abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus, extensor indicis
What is the origin of the supinator muscle? Where does this muscle insert? What nerve innervates this muscle?
a. origin - from lateral epicondyle and ulna, wraps around radius
b. inserts - on medial surface of the radius
c. innervated by the deep branch of radial nerve
What is the origin of the adbuctor pollicis longus muscle? Where does this muscle insert? What innervates this muscle?
muscle of anatomical snuff box
a. origin - from radius and ulna
b. inserts - on base of first metacarpal
c. passes through the first compartment under extensor retinaculum d. innervated by the posterior interosseous nerve
Where does the extensor pollicis brevis originate? Where does it insert? What innervates this muscle?
a. origin - from radius
b. inserts - on proximal phalanx of thumb
c. passes through the first compartment under extensor retinaculum
d. innervated by the posterior interosseous nerve
Where does the extensor pollicis longus muscle originate? Where does it insert? What innervates this muscle?
muscle of anatomical snuff box
a. origin - from ulna
b. inserts - on base of the distal phalanx of thumb
c. passes through the third compartment and changes direction at the
dorsal radial tubercle (Lister’s tubercle)
d. innervated by the posterior interosseous nerve
Where does the extensor indicis originate? Where does it insert? What innervates this muscle?
a. origin - from ulna
b. inserts - on extensor hood of index finger
c. passes through the fourth compartment under extensor retinaculum d. innervated by the posterior interosseous nerve
Where is the recurrent interosseous artery?
remains deep to the anconeus muscle
Where is the posterior branch of the anterior interosseous artery?
appears above the wrist
Where are the medial and lateral dorsal carpal arteries?
small arteries at the wrist
Where is the first dorsal metacarpal artery?
appears to be continuation of radial artery after the
perforating branch enters the palm
Where is the dorsal carpal arch?
supplied by the dorsal carpal branches of the radial and ulnar
arteries and anterior and posterior interosseous arteries
Where are the dorsal metacarpal arteries?
branches of the dorsal carpal arch to carry blood to
the fingers
Where is the dorsal digital artery?
one on each side of each finger
What nerve supplies the posterior muscles of the forearm?
radial nerve
What two muscles are supplies by the main trunk of the radial nerve in the forearm?
the main trunk supplies extensor carpi radialis longus and brachioradialis muscles
before it divides
What are the two branches of the radial nerve? What muscles do they serve? What nerve serves the rest of the muscles of the posterior forearm?
- superficial radial nerve - purely cutaneous to posterior forearm and
hand - deep radial nerve - supplies the extensor carpi radialis brevis and
supinator muscles - all other posterior forearm muscles are innervated by the posterior
interosseous nerve
