Posted by esb on September 23, 2011 at 22:22:09:
In Reply to: Flexor Region of the Forearm: Learning Objectives and Review Questions posted by lae2 on September 22, 2011 at 14:36:33:
: Flexor Region of the Forearm: Learning Objectives and Review Questions
: These questions were not submitted by the lecturer.
: True/False - 2011
The posterior relationships of the medial humeral epicondyle include the ulnar nerve, inferior ulnar collateral artery, and the humeral head of origin of the flexor carpi ulnaris.
F - superior ulnar collateral artery
The proximal margin of the trochlear notch is contributed by the coronoid process.
F - distal
The interosseous membrane has fiber directions that resist proximal displacement of the radius.
F - Wouldn't the distal-medial direction resist distal displacement?
The interosseous membrane limits forces transmitted to the capitilum.
T
The styloid process of the ulna has an articular disk mediatiing articulations between the radius and the scaphoid bone.
F - There is an articular disk between the radius and the ulna, though it adjoins the medial aspect of the radius. The scaphoid articulates with the distal-lateral aspect of the radius.
The hook of the hamate provides attatchment for the medial side of the transverse carpal ligament.
T - or at least looks like it in Netter.
The medial epicondyle of the humerus provides a site of attachment for the common flexor tendon.
T
Pronator teres has two heads of origin and, by one head, is a flexor of the elbow.
T - by the humeral head
A complete lesion of the musculocutaneous nerve entirely eliminates flexion of the forearm.
F - see previous question. Pronator teres can flex the forearm and is innervated by the median nerve.
A complete lesion of the musculocutaneous and radial nerves entirely eliminates flexion of the forearm.
F - see above?
A complete lesion of the musculocutaneous, radial, and ulnar nerves entirely eliminates flexion of the forearm.
F - see above?
A complete lesion of the musculocutaneous, radial, median, and ulnar nerves entirely eliminates flexion of the forearm.
T - this would eliminate all the lines (branches?) of the brachial "M" descending into the forearm.
A complete lesion of the radial nerve weakens flexion at the elbow.
T - loss of brachioradialis
A complete lesion of the ulnar nerve is expected to cause the resting position of the wrist to be extended and radially deviated wrist.
T - loss of flexor carpi ulnaris
A complete lesion of the radial nerve is expected to cause the resting position of the wrist to be adducted and flexed.
T - loss of extensor carpi radialis?
A complete lesion of the medial nerve is expected to cause the resting position of the wrist to be adducted and extended.
There's a medial nerve?
A complete lesion of the musculocutaneous leaves the resting position of the wrist to be neutral.
T?
A complete lesion of the ulnar nerve is expected to cause the resting position radial two fingers to be hyperextended at the metacarpophalangeal joint.
F - ulnar two fingers?
A complete lesion of the ulnar nerve is expected to cause the resting position radial two fingers to be flexed at the interphalangeal joints.
F - 4th and 5th digits (the ulnar two fingers)
A complete lesion of the ulnar nerve is expected to cause the resting position ulnar two fingers to be hyperextended at the metacarpophalangeal joint.
T
A complete lesion of the ulnar nerve is expected to cause the resting position ulnar two fingers to be flexed at the interphalangeal joints.
T
The anterior interosseous nerve, but not the brachial artery, passes posterior to the humeral head of the pronator teres.
T - brachial has usually already split into radial/ulnar somewhere in the cubital fossa
The radial two heads of the flexor digitorum profundus muscle are innervated by the superficial branch of the radial nerve.
F? - anterior interosseus branch of median nerve? It seemed like in lecture there were only two heads of this muscle (coming from ulna and coming from interosseus membrane), so I'm not sure what "radial two heads" means here.
Flexion of the distal interphalangeal joints is provided for by one muscle only whereas intrinsic mucles and long extensors act together to extend the distal interphalangeal joints.
F? - It looks like only flexor digitorum profundus flexes the DIP joints and only extensor digitorum extends them.
The pronator quadratus receives the most distal motor innervation from the posterior interosseous nerve.
F - I don't know what receives the most distal innervation of this nerve, but it can't be pronator quadratus. It's innervated by the anterior interosseus branch of median nerve.
The antebrachial fascia has medial and lateral intermuscular septae.
F? - seems like in lab today I was dissecting through many small septae surrounding individual muscles, rather than a single medial or lateral septa on each side of the bones.
Immediately posterior to the small gap between flexor carpi radialis and palmaris longus at the wrist is the median nerve.
F - between plantaris and flexor pollucis longus.
At the mid-forearm level the ulnar artery and nerve are lateral to the flexor carpi ulnaris, medial to flexor digitorum superficialis, and anterior to the flexor digitorum profundus.
T - they are medial to most of flexor digitorum superficialis, although I think it could also be argued that they are instead posterior.
The pisiform bone and the tubercle of the scaphoid bone provide proximal attachments for the flexor retinaculum.
T
The ulnar nerve lies lateral to the ulnar artery within Guyen's tunnel.
F - medial
The tendon of flexor carpi radialis is at risk for compression ischemia if carpal tunnel syndrome is in effect.
F - it's in its own little tunnel? Mechanistically though, I'm thinking that if there's inflammation/irritation of the carpal tunnel, it will tighten the anterior and posterior layers forming the tunnel for FCR, thus maybe compressing it.
Compression of the median nerve within the carpal tunnel may lead to a supinated resting position for the thumb (ape hand).
T? If the thumb can supinate without the rest of the hand. The thumb is adducted and rotated (laterally?) and opposition is lost.
True/False - 2010
The posterior interosseous artery, together with the posterior interosseous nerve passes from the anterior compartment of the forearm to the posterior compartment on the forearm
through an interval superior to the interosseous membrane and inferior to the oblique cord.
F - just the posterior interosseus artery. The posterior interosseus nerve is a continuation of radial nerve and passes deep to supinator
The predominate fiber direction of the interosseous membrane is from proximal superior and lateral to distal inferior and medial.
T
The anterior boundary of the carpal tunnel is the flexor retinaculum.
T
The pronator teres has two heads of origin; one head is biarticulate and one head is monoarticulate.
F? It has two heads of origin (Common flexor tendon and coronoid process), but I'm not aware of either being biarticulate
At the level of the hook of the hamate the ulnar nerve lies medial to the ulnar artery.
F - nerve is lateral
Entrapment of the ulnar nerve in Guyan's canal is expected to cause a "claw hand" syndrome.
T
Entrapment of the ulnar nerve at the medial epicondyle of the humerus may cause the relaxed wrist to be abducted and extended.
T if radial deviation = abducted
True/False - 2009
Flexor carpi ulnaris shares an attachment with the abductor digiti minimi.
T? - flexor carpi ulnaris inserts on the pisiform. Abductor digiti minimi takes origin from there.
Passing between the two heads of origin of the flexor carpi ulnaris is the inferior ulnar collateral artery.
F - posterior ulnar recurrent
Passing between the heads of origin of the pronator teres is the median nerve and the brachial artery.
F? - Netter has the ulnar head inferior to the brachial artery split, the ulnar artery running deep to both heads, and the median nerve runs between the heads.
Passing posterior to the free edge of the flexor digitorum superficialis is the anterior interosseous nerve.
T
Tethering of the flexor digitorum superficialis tendons to the flexor digitorum profundus tendons permit superficialis to flex the distal interphalangeal joint.
T
The medial two heads of the flexor digitorum profundus are innervated by the median nerve whereas the lateral two heads are innervated by the radial nerve.
F - medial half is ulnar, lateral half is anterior interosseus branch of median
A lesion of the median and ulnar nerves within the axilla causes uncompensated loss of flexion at the elbow.
F - the musculocutaneous would still work, so brachialis, biceps brachii would still be functioning
Lesions of the median, ulnar, and musculocutaneous nerves within the axilla result in uncompensated loss of flexion at the elbow.
F - brachioradialis innervated by radial nerve would still be working
A complete lesion of the ulnar nerve at the ulnar groove results in an abducted and extended position of the wrist.
T?
Passing lateral to the pisiform bone and then medial to the hook of the hamate are the ulnar nerve and artery.
F? - Netter has them passing lateral to pisiform, but they still look lateral to hook of hamate
Compression of structures within the carpal tunnel are expected to weaken the hypothenar muscles.
F - thenar
Medial attachments of the flexor retinaculum include the pisiform bone and the hook of the hamate.
T
Lateral attachments of the flexor retinaculum include the scaphoid tubercle and the trapezoid bone.
F - trapezium
The most distal skeletomotor distribution of the posterior interosseous nerve is the pronator quadratus.
F - I think this gets innervation from the anterior interosseus N?
The median nerve is separated from the anterior interosseous nerve by the muscle belly of the flexor digitorum superficialis.
F - by profundus, maybe, but superficialis is superficial to both of them
Flexor Carpi Ulnaris orginates from the lateral epicondyle of the humerus and courses posterior to the flexor retinaculum.
F - inferior
Pronator teres is considered to be a deep flexor of the forearm
F - superficial
Palmaris Longus helps to tense the palmar aponeurosis, flexes the hand, and extends the forearm.
T
Flexor Carpi Radialis is included in the carpal tunnel.
F - it has its own little tunnel on the lateral side of the main tunnel, formed by anterior and posterior reflections of flexor retinaculum
The ulnar nerve enters the forearm between the two heads of flexor carpi ulnaris then courses deep to flexor carpi ulnaris and flexor digitorum profundus.
F - deep to ulnaris, superficial to profundus. Does it enter the forearm between the two heads or posterior to both heads?
The superficial branch of the radial nerve is anterior to pronator teres and deep to flexor carpi radialis and brachioradialis.
T - it's anterior to the insertion of pronator teres
Entrapment of the median nerve between the two heads of pronator teres with cause an inability to pronate the forearm.
T? - pronator teres and quadratus are both innervated by median nerve
As the median nerve courses distally in the forearm it is located anterior to flexor digitorum superficialis.
F - posterior
Flexor digitorum superficialis inserts on the sides of the distal phalanges of fingers 2-5.
F - anterior bases of middle phalanges
All of the muscles in the flexor region of the forearm are innervated by the median nerve or anterior interosseus nerve.
F - Flexor carpi ulnaris and half of flexor digitorum profundus are by ulnar
The anterior interosseus artery courses anterior to pronator quadratus.
T
The anterior ulnar recurrent artery courses between brachialis and pronator teres to anastomose with inferior ulnar collateral artery.
T
The radial recurrent artery is located within the cubital fossa.
T - by definition as per Dr Evey, 21 Sept 2011
A complete lesion of the ulnar nerve at the ulnar groove will cause the wrist to be partially extended and partially abducted (radially deviated).
T
The pronator teres has a humeral head of origin and a radial head of origin.
F - ulnar instead of radial
The interosseus recurrent artery will course through supinator and lie deep to anconeus.
T
The ulnar nerve is located in the carpal tunnel.
F - anterior to it
The flexor pollicus longus flexes the thumb as well as assisting in abduction of the hand at the wrist.
F - doesn't abduct?
The pronator quadratus' primary action is pronation, however is can "switch" origin and insertion and act as a supinator with the forearm and hand are fully pronated.
T?
The flexor digitorum profundus can flex the DIP, PIP, and MP joints as well as assisting in flexion of the hand at the wrist.
T