The wrist and hand

Question 1

Name three muscles in the thenar compartment

Answer 1

1. Abductor Pollicis Brevis
2. Opponens Pollicis
3. Flexor Pollicis Brevis

Question 2

What is the origin, insertion, action and innervation of Abductor Pollicis Brevis

Answer 2

Origin: Flexor retinaculum, scaphoid, trapezium

Insertion: lateral side of proximal phalanx of the thumb

Action: abducts the thumb

Innervation: median nerve

Question 3

What is the origin, insertion, action and innervation of Opponens Pollicis

Answer 3

Origin: Flexor retinaculum, scaphoid, trapezium

Insertion: 1st metacarpal

Action: draws 1st metacarpal to oppose the pinky in the center of the palm

Innervation: median

Question 4

What is the origin, insertion, action and innervation of Flexor Pollicis Brevis

Answer 4

Origin: Flexor retinaculum, scaphoid, trapezium

Insertion: lateral side of proximal phalanx of the thumb

Action: flexes thumb

Innervation: median and ulnar

Question 5

Name the 3 muscles in the hypothenar compartment

Answer 5

1. Abductor Digiti Minimi
2. Opponen Digiti Minimi
3. Flexor Digiti Minimi

Question 6

What is the origin, insertion, action and innervation of Abductor Digiti Minimi

Answer 6

Origin: pisiform

Insertion: medial side of the proximal phalanx of the pinky

Action: abducts the pinky

Innervation: ulnar nerve

Question 7

What is the origin, insertion, action and innervation of Opponen Digiti Minimi

Answer 7

Origin: flexor retinaculum and hook of hamate

Insertion: medial 5th metacarpal

Action: draws 5th metacarpal to oppose the thumb in the center of the palm

Innervation: ulnar nerve

Question 8

What is the origin, insertion, action and innervation of Flexor Digiti Minimi Brevis

Answer 8

Origin: flexor retinaculum and hook of hamate

Insertion: medial side of the proximal phalanx of the pinky

Action: flexes pinky

Innervation: ulnar nerve

Question 9

Name the 2 interossei muscles and describe there origin, insertion, function and innervation

Answer 9

Palmer and Dorsal interossei

Origin: palmar or dorsal metacarpals

Insertion: digits 2-5

Action: adducts digits like Spock hands when he says live long and prosper

Innervation: ulnar nerve

Question 10

What is the origin, insertion, action and innervation of Lumbricals

Answer 10

found inbetween the metacarpals

Origin: distal portion of flexor digitorum profundus tendons

Insertion: distal portion of extensor digitorum tendons

Action: flexes and extends fingers

Innervation: median and ulnar nerves

Question 11

What is the origin, insertion, action and innervation of Adductor Pollicis

Answer 11

Origin: anterior side of 2nd and 3rd metacarpals

Insertion: medial side of proximal phalanx of the thub

Action: adducts thumb

Innervation: ulnar nerve

Question 12

What is the extensor retinacula and what is it fxn

Answer 12

Fascia in the that extends over the posterior portion of the radius and ulna

fxn= to keep the extensor tendons in position and prevent “bowstringing”

Question 13

What bones do the is the flexor retinacula (transverse carpal ligament) connect

Answer 13

the scaphoid and trapezium bones on the radial side to the hamate and pisiform on the ulnar side

Question 14

What is the area inferior to the flexor retinacula and superior to the distal carpals

Answer 14

the carpal tunnel

Question 15

What important structures lie within the carpal tunnel

Answer 15

the tendons of the flexor pollicis longus, the flexor digitorum superficialis, flexor digitorum profundus, and the median nerve

Question 16

What nerve does carpal tunnel syndrome affect

Answer 16

the median nerve

Question 17

Even though the palmer cutaneous nerve is a branch of the median nerve why is NOT affected in carpal tunnel syndrome

Answer 17

because it branches from the median nerve proximal to the carpal tunnel

Question 18

What important structures lie between the palmar carpal ligament and the flexor retinacula

Answer 18

the ulnar nerve, the palmaris longus nerve, and the ulnar artery (These are NOT in carpal tunnel)

Question 19

Why is coordination of thumb lost in carpal tunnel

Answer 19

because the median nerve innervates the thenar muscles

Question 20

How can you detect irritated nerves like in the case of carpal tunnel

Answer 20

Tinels sign= its were you tap on a nerve to illict a pins and needles feeling (paraesthia)

Question 21

What is skiers thumb

Answer 21

the rupture of the ulnar collateral ligament of the thumb

Question 22

What important structures lie deep to the anatomical snuff box

Answer 22

the radial artery, the radial nerve, the scaphoid and the trapezium

Question 23

Pain in the anatomical snuff box after a fall on an outstretched hand may indicate what and why is it important

Answer 23

fx scaphoid

important because scaphoid fx may cause loss of blood supply to that area, and since this area is where the wrist/hand articulates with the radius loss of blood= necorsis= loss of wrist fxn.

Question 24

What 2 arteries form the superficial palmar arch

Answer 24

the superficial ulnar and radial arteries

Question 25

What is Allen’s test

Answer 25

test the patency of the radial and ulnar arteries as well as the collateral circulation of the hand

commonly used to reduce risk of ischemia prior to radial ABG