Anatomy Quiz 5+

"Which of the following concerning the movement of the metacarpophalangeal joints is *not* correct?" Which is correct?

*NOT*: The movement away from the midline of the middle finger is performed by the palmar interossei *CORRECT*: > the lumbrical and interossei, assisted by the flexor digitorum superficialis, produce flexion > adduction is performed by the palmar interossei > extension is performed by the extensor digitorum, extensor indicis, and extensor digiti minimi

What are the 3 thenar muscles (the swollen part of the palm under the thumb) and what nerve innervates them?

1. abductor poliicis brevis (deep ulnar) 2. flexor pollicis brevis (recurrent median) 3. opponens pollicis (recurrent median)

Anatomical snuffbox: 1. What structures lie within? 2. What structures make up the borders? 3. What carpal bone lies deep to it?

1. radial artery, radial nerve, cephalic vein, 2. extensor pollicis longus and brevis, retinaculum 3. scaphoid

What test is used to check patency of palmar arches or occlusion of the radial or ulnar artery? (failure of change of hand color when opening fist)

Allen Test

Deformity? Injury to the recurrent branch of the *median nerve*--> paralysis of the three thenar muscles

Ape thumb REMEMBER: Adductor policis is supplied by *ulnar nerve*, and would not be affected

A fracture/separation, common in children because of frequent falls that transmit force from the hand to the radius:

Epiphyseal injury

"Regarding the superficial palmar arch, which of the following is correct?"

It is formed by the continuation of the ulnar artery in the palm

Which (palmar or dorsal) performs abduction or adduction?

PADS and DABS Palmar: adduction Dorsal: abduction

What are the 8 carpal bones?

Scaphoid, Lunate, Triquetrum, Pisiform, Trapezium, Trapezoid, Capitate, Hamate "She Looks Too Pretty Try To Catch Her"

"One of the following is correct regarding the radiocarpal joint"

The distal surfce of the radius articulates with the scaphoid and lunate bones (and triquetral bones) side note: > biaxial synovial joint, ellipsoid

Condition in which one of the fingers gets stuck in a bent position and may straighten with a snap (quickly), stenosing tenosynovitis:

Trigger finger

Compression of the ulnar nerve at the wrist where it passes between the pisiform and hook of hammate; handlebar neuropathy:

Ulnar Canal Syndrome (Guyon Canal syndrome) side note: weakness of intrinsic muscles of the hand and clawing of the 4th and 5th digits may occur

What thumb muscle do humans have that chimpanzees do not that differentiates between a hook grip and a precision grip?

abductor pollicis longus

Thumb movement that combines flexion and rotation to facilitate movement of the thumb across the palm to touch other digits is:

apposition

"Which of the following muscles acts on the radioulnar joints?"

biceps brachii (attached at radial tuberosity, assists supination)

What makes up the osteofibrous canal of the carpel tunnel? What structures lie in the carpel tunnel? (10)

carpels and flexor retinaculum (4) flexor digitorum superficialis (4) flexor digitorum profundus (1) flexor pollicis longus (1) median nerve

"*Dupuytren's contracture* deformity is caused by:"

fibrosis of the palmar aponeurosis (affecting 4th and 5th digits)

If there is infection of the midpalmar hand and it progresses through the tunnel and involved space, where would an incision be made for draining?

forearm

"Dinner fork deformity is seen in:"

fracture in the distal end of the radius (*Colles fracture*)

If not drained immediately, pulp space infection can lead to___ due to loss of blood supply.

gangrene

What carpal bone is likely to be fractured while golfing?

hook of hammate

"A 44-year-old woman is diagnosed with posterior interosseous nerve palsy. When muscle function is examined, what findings are most likely to be present?"

inability to extend the digits at the metacarpophalangeal joints

"Regarding the extensor expansion (hood), which of the following is correct?"

it is found on the dorsum of the proximal phalanx (2nd-5th phalanges)

What is the function of the interosseous membrane?

load-sharing between radius and ulna

What carpal bone is most likely to dislocate?

lunate

"Carpel tunnel syndrome is a common clinical condition caused by a pinched:"

median nerve

"A dislocated lunate bone may compress on which of the following structures?"

median nerve in the carpel tunnel

"A 53-year-old man visits the clinic complaining of a *swelling over the dorsal aspect of the elbow*. The swelling is gradually increasing in size and is cystic in consistency. The patient feels *pain in the swelling when he fully flexes the elbow*. What is most likely diagnosis?"

olecrenon bursitis

"Which of the following muscles acting on the 1st digit (thumb) receives motor innervation from the recurrent branch of the median nerve?"

opponens pollicis

"Which of the following structures pass through the gap between the oblique cord and the upper border of the interosseous membrane?"

posterior interosseous artery side note: accompanied by posterior interosseous nerve; supplies deep extensor muscles

"Which of the following structures lies in the floor of the anatomic snuffbox?"

radial artery

What carpal bone is most likely to be fractured?

scaphoid

"The cephalic vein is constantly found in the superficial fascia posterior to the:"

styloid process of the radius side note: the styloid process is one of the bony structures near the anatomical snuffbox; the cephalic vein can be found in the superficial part of the anatomical snuffbox.

"Which of the following structures lies in the carpel tunnel?"

tendon of flexor pollicis longus muscle

"The annular ligament is attached to:"

the (anterior and posterior) margins of the radial notch of the ulna side note: no attachment to radius, allows radius to freely rotate within annular ligament

"Regarding Nursemaid's elbow, which of the following is correct?"

the head of the radius slips out of the annular ligament side note: *sublaxation of the radial head* usually when jerking child out of street- *arm jerked upward while pronated*

"The ulnar collateral ligament of the elbow joint is easily closely related to the:"

ulnar nerve

Dislocation of the elbow likely causes injury to what nerve?

ulnar nerve (numbness of little finger, weak flexion and adduction of wrist and intrinsic muscles of the hand)

"The carrying angle of the elbow disappears:"

when the forearm is pronated