Forearm Flashcards
What holds the tendons of most of the flexor muscles in place?
palmar carpal ligament and the flexor retinaculum (transverse carpal ligament)
What group of muscles are in the anterior part of the forearm?
flexor-pronator muscles
What flexor muscles are part of the superficial layer?
pronator teres, flexor carpi radialis, palmar longus, and flexor carpi ulnaris
What is the common flexor origin?
medial epicondyle of humerus
What flexor muscles are part of the intermediate layer?
flexor digitorum superficialis
What flexor muscles are part of the deep layer?
flexor digitorum profundus, flexor pollicis longus, and pronator quadratus
Which muscles do not cross the elbow joint?
the three deep flexor muscles; flexor digitorum profundus, flexor pollicis longus, and pronator quadratus
What is the prime mover for pronation?
pronator quadratus
The ___ flexes the fingers during slow action; this action is reinforced by the ___ when speed and flexion and resistance is required.
FDP; FDS
TRUE or FALSE.
Long flexor muscles of the fingers are more efficient when the wrist is flexed.
False
What muscles are located in the posterior compartment of the forearm?
extensor muscles
All extensor muscles are innervated by what nerve?
radial
What muscles extend and abduct or adduct the wrist joint?
extensor carpi radialis longus, extensor carpi radialis brevis, and extensor carpi ulnaris
What muscles extend the medial four digits?
extensor digitorum, extensor indicis, and extensor digiti minimi
What muscles extend or abduct the thumb?
abductor pollicis longus, extensor pollicis brevis, and extensor pollicis longus
What does the extensor retinaculum do?
holds the extensor tendons in place; prevents bowstringing of tendons during wrist extension
What do synovial tendon sheaths do?
reduce friction for extensor tendons
What are the superficial extensors of the forearm?
Brachiradialis, ECRL, ECRB, extensor digitorum, EDM, and ECU
What superficial extensors are commonly attached by a common extensor tendon to the lateral epicondyle?
ECRB, extensor digitorum, EDM, and ECU
What superficial extensor muscles are attached to the lateral supraepicondylar ridge of the humerus and the adjacent lateral intermuscular septum?
Brachioradialis and ECRL
TRUE or FALSE?
No finger can remain fully flexed as the other ones are fully extended.
True
What are the deep extensor muscles of the forearm?
APL, EPB, EPL
What are the outcropping muscles?
Deep extensor muscles; APL, EPB, EPL, and extensor indicis
What are the lateral borders of the snuff box?
The tendons of the APL and the EPB
What is the medial border of the snuff box?
Tendon of the EPL
What structures are at the floor of the snuff box?
The radial artery, scaphoid, and trapezium
What restricts independent extension of the fingers?
Intertendinous connctions
What are the major nerves of the forearm?
Median, ulnar, and radial nerves
What is the principal nerve of the anterior compartment of the forearm?
Median nerve
What is the major branch of the median nerve?
Anterior interosseous nerve
What are the main arteries of the forearm?
Ulnar and radial arteries
Where can pulsations of the ulnar artery be palpated?
Lateral side of the FCU tendon
Where can pulsations of the radial artery be palpated?
Distal radius between the tendons of FCR and APL
What is the origin of the anterior interosseous nerve?
median nerve in distal part of cubital fossa
What is the origin of the palmar cutaneous branch of median nerve?
median nerve of middle to distal forearm, proximal to flexor retinaculum
What is the origin of the palmar cutaneous branch of the ulnar nerve?
ulnar nerve near middle of forearm
What is the origin of the dorsal cutaneous branch of ulnar nerve?
ulnar nerve in distal half of forearm
What is the origin of the posterior cutaneous nerve of forearm?
radial nerve, as it transverses radial groove of posterior humerus
What is the origin of the superficial branch of radial nerve?
sensory terminal branch of radial nerve, in cubital fossa
What is the origin of the deep branch of radial/posterior interosseous nerve?
motor terminal branch of radial nerve, in cubital fossa
What is the origin of the lateral cutaneous nerve of forearm?
continuation of muscultaneous nerve distal to muscular branches
What is the origin of the medial cutaneous nerve of forearm?
medial cord of brachial plexus, receiving C8 and T1 fibers