lecture 9: wrist and hand

Recall the bones of the hand and their key characteristics. Appreciate how they articulate with the radius and ulna. Describe the wrist joint, the range of movements that can occur at it, and the structures that stabilise it. Identify the major muscle groups in the hand and describe their actions. Identify the major nerves that supply the muscles of the hand and appreciate their segmental distribution. Describe the pattern of blood supply and venous drainage in the hand.

whats a Retinaculum

band of thickened tissue that stabilises tendons around joints, preventing them from popping up when the joint is flexed or extended. From the Latin verb retinere, "to retain".

what reticulums are in the wrist

flexor and extensor

label structures 1-3

dorsal venous arch, basilic vein, cephalic vein

label structures 1-4

DPA, RA, SPA, UA

label structures 1-4

right subclavian, axillary, deep brachial, brachial

label structure 5-9

radial, ulnar, deep palmar arch, superficial palmar arch, digital

label structures 1-5

subclavian, axillary, cephalic, subscapular, brachial

label structures 6-15

basilic, median cubital, cephalic, radial, median antebrachial

label structures 11-14

basilic, ulnar, palmar venous arches, digital

what are the blood vessels of the hand from aortic arch?

From arch of the aorta: L/R subclavian artery → axillary artery → brachial artery → radial and ulnar arteries → superficial and deep palmar arches + dorsal carpal arch

what are the blood vessels of the hand from the digits?

 digital veins → palmar venous arches + dorsal venous arch → cephalic and basilic veins (superficial) + radial and ulnar veins (deep) → brachial vein (deep)  ⇉ axillary vein →   L/R subclavian vein → L/R brachiocephalic vein → SVC

label structures 1-5

distal phalanx, middle phalanx, proximal phalanx, metacarpal, trapezium

label structures 6-10

trapezoid, scaphoid, radius, phalanges, metacarpals

label structure from 11-15

carpal bones, capitate, hamate, pisiform, triquetrum

label structure 16 and 17

lunate, ulna

what bones are in the proximal row of the hand?

Scaphoid

Lunate

Triquetrum

Pisiform

what bones are in the distal row of the hand?

Hamate

Capitate

Trapezoid

Trapezium

label structures 1-5

1st metacarpal, 2nd metacarpal, 3rd metacarpal, 4th metacarpal, 5th metacarpal

label structures 6-10

trapezium, trapezoid, hamate, capitate, pisiform

label structures 11-15

scaphoid, lunate, triquetrum, radius, ulnar

label structures pink to red

scaphoid, lunate, triquetrum, pisiform

label structures orange to blue

trapezium, trapezoid, capitate, hamate

what are these?

metacarpal phalangeal joints

what are these joint?

interphalangeal joints

what do the metacarpal phalangeal joints do?

Allow flexion, extension, adduction*, abduction* and circumduction (*very limited)

what do the interphalageal joints do?

Only allow flexion and extension

whats different between the joints on digits 2-5 and digit 1

2-5 have two interphalangal joints, 1 has 1

fill in the missing labels

flexion, extension, abduction, adduction, opposition

what is the thenar eminence associated with

pollicis (digit 1)

whats the hypothenar eminence associated with?

digit 5 (minimis)

what movements do the hand eminances control?

abduction, flexion and opposition of their respective digit

what are the missing structures that make up the thenar eminence?

flexor pollicis brevis, abductor pollicis brevis, opponens pollicis brevis

what is the missing structure which is part of the hypothenar eminence

opponens digit mininimi

what are the missing structures (part of the hypothenar eminance)

flexor digiti minimi brevis, abductor minimi brevis

what does the palmar brevis do?

pulls on skin over hypothenar eminence, deepening the cup of the palm and so improving grip

what does the adductor pollicis do?

adducts digit one

what do the palmar interossi do?

adduct digits 2,4,5 towards longitudinal axis

what muscle is this?

palmar brevis

what muscle is this?

adductor pollicis

what muscle is this?

palmar interossi

whats the blood supply to the thenar eminence?

superficial palmar arch

whats the innervation of the thenar eminence

median n.

whats the blood supply of the hypothenar eminence?

ulnar a.

whats the innervation of the hypothenar eminence?

ulnar n

what is the blood supply to the palmaris brevis, adductor pollicis, palmar interossi?

deep palmar arch

what is the innervation to the palmaris brevis, adductor pollicis, palmar interossi?

ulnar nerve

whats the innervation to the lumbricals?

superficial and deep palmar arches

whats the innervation to the lumbricals?

ulnar and median n.

whats the action of the lumbricals?

on digits 2-5 they flex MCP joints, extend IP joints

what muscle is this?

lumbricals

what muscle is this?

dorsal interossei

what is the action of the dorsal interrossei

abduct digits 2-4 away from the hand's longitudinal axis (middle finger). Assist in flexion at the MCP joints and extension at the IP joints of digits 2-4

whats the nemonic to remember the different actions of the palmar and dorsal interossei?

PAD (palmar interossei adduct) & DAB (dorsal interossei abduct

what is the blood supply to the dorsal interossei muscles?

dorsal carpal arch

what is the innervation to the dorsal interossei muscle?

ulnar n.