B7.018 Forearm, Cubital Fossa and Hand

Question 1

2 compartments in the forearm

Answer 1

anterior (volar)
posterior (dorsal)
separated by the two bones and the interosseous membrane
each has its own deep fascia

Question 2

anterior forearm compartment

Answer 2

anteromedial
muscles originate from the medial epicondyle and medial epicondyle ridge of humerus
innervated by median and ulnar nerves

Question 3

posterior forearm compartment

Answer 3

posterolateral
muscles originate from the lateral epicondyle and lateral epicondyle ridge of the humerus
function as extensors and supinators
innervated by radial nerve

Question 4

structure of forearm muscles

Answer 4

fleshy masses at proximal part of forearm

form tendons as they approach the distal forearm and tendons continue into the wrist, hand, and digits

Question 5

what is the anterior interosseous nerve

Answer 5

branch of median nerve at distal cubital fossa

Question 6

what does the anterior interosseous innervate

Answer 6

lateral FDP
flexor pollicis longus
pronator quadratus
(deep anterior forearm muscles)

Question 7

forearm skin innervation

Answer 7

medial side = medial cutaneous

lateral side = musculocutaneous

Question 8

hand skin innervation

Answer 8

anterior radial 3.5 fingers/palm = median
posterior radial 3.5 fingers = radial
anterior / posterior ulnar 1.5 finger/palm = ulnar

Question 9

recurrent branch of median nerve

Answer 9

supplies 3 thenar muscles

comes out of the carpal tunnel woohoo

Question 10

flexor retinaculum

Answer 10

transverse carpal ligament
dense CT band that bridges between trapezium and pisiform, plus hook of hamate
roof of carpal tunnel

Question 11

palmar carpal ligament

Answer 11

superficial to flexor retinaculum

rook of Guyon’s canal (ulnar nerve)

Question 12

what structures make the canal of Guyon

Answer 12

pisiform and hook of the hamate

Question 13

branches of the brachial artery

Answer 13

branches into ulnar (larger) and radial (smaller) at the head of the radius in the lower cubital fossa region

Question 14

branches of the ulnar artery

Answer 14

-common interosseous artery
divides immediately into:
anterior interosseous artery
posterior interosseous artery
-muscular branches: muscles on medial forearm

Question 15

superficial palmar arch

Answer 15

continuation of the ulnar artery that anastomoses with the radial artery

Question 16

deep palmar arch

Answer 16

deep branch of ulnar artery that anastomoses with radial artery

Question 17

significance of radial artery location

Answer 17

demarcation for the separation of the flexors and extensors of the forearm
runs across floor of anatomical snuff box (pulse)

Question 18

US DR relationship

Answer 18

Superficial palmar arch is mainly Ulnar artery

Deep palmar arch is mainly Radial artery

Question 19

borders of anatomical snuff box

Answer 19

top: extensor pollicis longus
bottom: extensor pollicis brevis

Question 20

contents of anatomical snuff box

Answer 20

radial artery on floor

scaphoid, trapezium, and 1st CMC

Question 21

deep branch of radial nerve

Answer 21

muscular and articular

injury: inability to extend thumb and MCPs

Question 22

superficial branch of radial nerve

Answer 22

cutaneous and articular

supplies skin on dorsal side of hand and a number of joints in the hand

Question 23

function of fibrous digital sheath

Answer 23

anchors flexor tendons to each phalanx with synovial sheath in between

Question 24

annular

Answer 24

all the way around

Question 25

cruciform

Answer 25

X shaped

Question 26

how many digital arteries per finger

Answer 26

4

Question 27

superficial branch of ulnar nerve

Answer 27

supplies medial one and a half digits on the anterior surface

Question 28

deep branch of ulnar nerve

Answer 28

hypothenar muscles
medial 2 lumbricals
adductor pollicis
interossei muscles

Question 29

dorsal branch of ulnar nerve

Answer 29

supplies medial half of dorsum hand, 5th digit, and medial half of 4th digit

Question 30

radial nerve innervation of the hand

Answer 30

no intrinsic hand muscle innervation

innervates skin of lateral 2/3 of dorsum

Question 31

ligaments of elbow joint

Answer 31

radial collateral

ulnar collateral

Question 32

radial collateral ligament

Answer 32

from lateral epicondyle to annular ligament of the radius

Question 33

ulnar collateral ligament

Answer 33

from medial epicondyle to coronoid process and olecranon of the ulna (3 bands):

1. anterior cordlike (strongest)
2. posterior fanlike (weakest)
3. oblique (deepens the socket for the trochlea)

Question 34

bursa around elbow

Answer 34

subtendinous
intratendinous
subcutaneous

Question 35

subcutaneous bursa

Answer 35

located in subcutaneous tissue over the olecranon

Question 36

when are hand grips the strongest

Answer 36

when wrist is extended