Hand & Wrist

Question 1

name the 8 carpal bones

Answer 1

scaphoid, lunate, triquetral, pisiform, trapezium, trapezoid, capitate, hamate

Question 2

what is retinacula?

Answer 2

thick deep fibrous bands running across the wrist to hold the tendons down (preventing bowstringing)

Question 3

what does the flexor retinaculum do?

Answer 3

runs over anterior carpal bones and holds down flexor tendons
median nerve passes under (carpal tunnel)

Question 4

what does the extensor retinaculum do?

Answer 4

runs on dorsal carpals and holds down extensor tendons

digits pass underneath

Question 5

explain the structure of the carpal tunnel in reference to the floor and roof

Answer 5

floor - concave arch of carpal bones covered by extrinsic palmar ligaments
roof - flexor retinaculum attached to scaphoid, trapezium, pisiform and hamate

Question 6

what are the contents of the carpal tunnel?

Answer 6

9 flexor tendons, vascular synovium and median nerve

Question 7

name the tendons in the carpal tunnel

Answer 7

4 flexor digitorum profundus
4 flexor digitorum superficialis
flexor pollicis longus

Question 8

explain the 2 main movements of the hand

Answer 8

non-prehensile - pushing, hitting
prehensile - grasp and grip

Question 9

what are the 2 types of grip?

Answer 9

power - palm grasp (strong, allows holding or punch), wrist extended

precision - fine control, done by extrinsic flexors and extensors

Question 10

what are the actions of the metacarpopharyngeal joints?

Answer 10

flexion/extension
abduction/adduction

Question 11

explain the actions of the interphalyngeal joints

Answer 11

flexion/extension

Question 12

what groups of muscles move the hand, wrist and fingers?

Answer 12

intrinsic - belly inside palm (intricate movements)

extrinsic - belly outside hand, long flexors and extensors (power grip)

Question 13

name the flexor muscles of the digits and their innervation

Answer 13

palmaris longus
flexor digitorum superficialis/profundus
flexor pollicis longus

innervation - median nerve

Question 14

name the extensor muscles of the digits and their innervation

Answer 14

extensor digitorum
extensor digiti minimi
extensor indices

innervation - radial nerve

Question 15

what muscles make up the hypothenar eminence and what is their innervation?

Answer 15

abductor digiti minimi
flexor digiti minimi
opponens digiti minimi

innervation - ulnar nerve

Question 16

what muscles make up the thenar eminence and what is their innervation?

Answer 16

abductor pollicis brevis
flexor pollicis brevis
opponens pollicis

innervation - median nerve

Question 17

lumbricals: actions and innervations

Answer 17

actions:
digit flexion (metacarpophalyngeal joints)
digit extension (interpharyngeal joints)

innervations - median nerve (lateral 2), ulnar nerve (medial 2)

Question 18

name the interossei muscles, how many there are, and state their actions and innervation

Answer 18

palmar (3) and dorsal (4)

actions:
digit adduction (palmar)
digit abduction (dorsal)

innervation - ulnar nerve

Question 19

what is the anatomical snuff box?

Answer 19

triangular deepening on the lateral dorsal hand
scaphoid and trapezium bones on floor

Question 20

what is the snuffbox bound by?

Answer 20

medial - extensor pollicis longus tendon

lateral - extensor pollicis brevis, abductor pollicis longus

proximal - radial styloid process

distal - 1st carpal-metacarpal joint