Re: Hand: Learning Objectives and Review Questions

Comments:
: : : Hand: Learning Objectives and Review Questions : : : These questions were not submitted by the lecturer. : Abduction of the thumb is orthogonal to abduction of the index finger. : : T : Agree. : : The ulnar is radial to the ulnar nerve at the proximal entrance to Guyen's canal. : : T - (ulnar artery?) : Agree. Ulnar artery : : Common digital arteries arise from the deep palmar arch. : : F - superficial palmar arch : Agree. Common metacarpal aa. : : The princips pollicis artery is generally regarded as a branch of the superficial palmar arch. : : F - deep palmar arch : Agree. Terminal branch radial a. : : A lesion of the recurrent median nerve causes atrophy of the hypothenar eminence. : : F - those muscles (opponens digiti minimi, abductor digit minimi, flexor digiti minimi) are innervated by the deep branch of the ulnar nerve : Agree. : : The insertion of extensor carpi radialis longus inserts radial (lateral) to the insertion of extensor carpi radialis brevis. : : T : Agree. : : Guyon's canal transmits the deep branch of the radial nerve. : : F - the ulnar nerve : Agree. : : Guyon's canal is anterior and radial to the transverse carpal ligament (flexor retinaculum). : : F - anterior and medial (ulnar) : Agree. : : The thenar muscles are innervated by the recurrent branch of the median nerve. : : T : Agree. : : Opposition of the thumb is lost, without compensation, in the case of recurrent medial nerve injury. : : T : Agree. : : The tendons of the interossei cross posterior to the deep transverse metacarpal ligament. : : T - and tendons of lumbricals cross anterior to it? : Agree. : : The tendons of the lumbricals cross posterior to the deep transverse metacarpal ligament. : : F? : Agree. See Gray's. : : The lateral bands of the extensor apparatus (hood) are largely derived from the tendons of the interossei and lumbrical mm. : : T? : False maybe. I don't remember my point at this minute. Still grading. Perhaps not a great question. : : The pisiform bone is anterior to the triquetrum. : : T : Agree. : : The triangular fibrocartilage complex is part of the distal radioulnar joint. : Agree. : : The pisiform bone is a sesamoid bone within the tendon of flexor carpi radialis. : : F - it's a sesamoid bone, but I'm thinking it's not completely encased in flexor carpi ulnaris. Does abductor digiti minimi originate on the bone itself or just from the flexor tendon? : True. You're splitting fibers (hairs) on this one I think. : : In part, the origin of the abductor digiti minimi is from the pisiform bone. : : Um. See above? : Agree. Forcefully abduct your fifth digit and watch FCU dance. : : The ulnar nerve enters the palm lateral to the pisiform bone and then passes the medial aspect of the hook of the hamate. : : T : Agree. Think about entrapment. Sports injuries to the hook. End of career. : : The hypothenar muscles are innervated by the median nerve with the exception of the lateral head of the flexor digiti mini brevis being innervated by the ulnar nerve. : : T - does flexor digiti minimi have two heads or a single head coming off both the hamate and the flexor retinaculum? : False. Hypothenar are in ulnar nerve territory. Two heads I believe. Check Gray's and lecture. : : The superficial branch of the ulnar nerve provides cutaneous sensation to the medial 1.5 fingers on the palmar side whereas the dorsal digital branch of the ulnar nerve innervates the nail bed of the middle finger. : : F in at least one way - the palmar digital branches of median nerve usually do middle finger nail bed. However, in the (relatively common) case that the innervation by the ulnar nerve extends one more digit medially, wouldn't the innervation of the nail bed still be the superficial branch of the ulnar nerve? : Agree. Palmar digital nerves, not dorsal, wrap around to the nail beds. The dorsal nn stop short. : : The third digit (middle finger), by definition, is not capable of adduction. : : T - it's defined as midline. Movement in either direction within the plane parallel to the palmar surface would be abduction. : Agree. Returning to the midline is NOT adduction. The reference moves with the digit. : : The intrinsic muscles of the hand, and the lumbricals in particular, play a key role in preventing hyperextension at the MP joint. : : T : Agree. Please understand claw hand and grip. : : In the event of paralysis of the medial lumbricals and all interossei (ulnar nerve injury), the thumb can be expected to supinate and, thus, the hand appears similar to an "ape hand." : : F - would be ulnar claw. Thumbb rotation would result from median nerve injury : Agree. : : The deep branch of the ulnar nerve passes deep into the palm of the hand along with the radial artery. : : F - along with the deep palmar branch of the ulnar artery : Agree. : : Both the superficial and deep palmar arches are fed by both the ulnar and radial arteries. : : T - radial predominates in deep palmar, ulnar predominates in superficial, but both arches involve both arteries : Agree. There is a clinical test for dominance. Demo by Dr. Hauck in the AM. : : The anterior interosseous nerve, after providing motor innervation pronator quadratus, continues onto the hand and supplies sensation to the joints of the wrist. : : T? : Agree. : : The radial artery approaches the hand along the lateral side of flexor carpi radialis but does not enter the palm of the hand without first entering the anatomical snuff box. : : T : Agree. : : The radial artery leaves the anterior compartment of the forearm by passing deep to the tendon of abductor pollicis longus and along the dorsal surface of the lunate bone. : : F - along dorsal surface of scaphoid? : Agree. : : Branches of the superficial radial nerve can be palpated as they cross the superficial surface of the extensor pollicis longus tendon. : : T? - they run there, but I don't know if they're palpable : Agree. Palpable in a much celebrated manner. : : Variable interdependence of the finger extensor tendons can be accounted for by variability in the intertendinus connections (nothing to do with vincula). : : T? : Agree. See Dr. Hauck's lecture. : : Vincula longa and brevia are continuous with the flexor tenden sheaths. : : T : Agree. They are synovial reflections. : : Although the vinculae are known for tethering the tendons, their primary function is to transport synovial fluid from the periosteal lining of the phalanges. : : F? - nerves and vessels. Synovial fluid would surround the vincula? : Agree. Synovial fluid is from the serous membrane. : : In the case of a "graceful grasp," flexion of the IP joints is retarded as the long flexors begin to flex the MP joint. : : T? : Agree. Think lumbricals. : : A graceful grasp depends on the integrity of the intrinsic muscles whereas a strong grip is largely dependent on flexor digitorum profundus. : : T? : False. Oddly. The long extensors put the zap into the grip. Mechanics of grip. Try to squeeze a tennis ball without extending your wrist. See Dr. Hauck's lecture in regard to wrist fusion. : : Although the long extensors are antagonistic to the long flexors, the long extensors are critical for a strong grip. : : T? : Agree. : : When fusing the wrist as a treatment for loss of extension the wrist is fused in a flexed position. : : F - at about 10* of dorsiflexion? : Agree. : : The heads of origin of the first dorsal interosseous muscle provide a passage way for the radial artery to leave the dorsum of the hand. : : T : Agree. : : The princeps pollicis artery passes along the medial border of the radial head of the first dorsal interosseous and the lateral border of the oblique head of adductor pollicis. : : T? - I need to find a better picture of this somewhere other than Netter, but it seems like it would work. : Agree. An appreciation for anatomical position of the thumb (90 deg orthogonal to palm) helps to evaluate this question. : : In anatomical position the volar surface of the thumb is 90 degrees opposed to the volar surface of the fingers. (This relates to the previous question) : : T : Agree. : : The anterior border of the "anatomical snuff box" is the dorsal surface of the scaphoid bone. : : T : Agree. : : A lacertion of the the thenar eminence can be expected to involve the recurrent median nerve. : : T : Agree. : : Median nerve injury at the wrist may result in uncompensated loss of opposition of the thumb. : : T : Agree. Please resist any depressive thoughts you may be having. Especially if you lack protection from the palmaris longus. That is why Anna is always happy. She dare not be. : : A fracture of the hook of the hamate can end the career of a professional athlete due to injury of the median nerve. : : F - ulnar nerve. Golfers and are scared of this one. Hit the ball, not the ground. : Agree. I hit the ground anyway. Gave my clubs away after one time. : : The extensor hood of the third digit receives contributions from the attachments of five tendons. : : F? - two dorsal interosseus, no palmar interosseus, one lumbrical, one extensor : Agree. : : The extensor hood of the second digit receives contributions from the attachments of five tendons. : : F? - one dorsal interosseus, one palmar interosseus, one lumbrical, one extensor : True. Extensor indicis. Sarah's lecture tomorrow.

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