The Hand

Front 1

Thenar Space vs Thenar Compartment(Eminence)

Back 1

Thenar Space - 1st Lumbrical, its posterior to long flexor tendon of the index finger and anterior to the adductor pollicis muscle

Thenar Compartment(Eminence) - Abductor pollicis brevis, Flexor pollicis brevis, Opponens pollicis

Front 2

Superficial Palmar Arch

Back 2

Ulnar artery passes superficial to the flexor retinaculum, lateral to the ulnar nerve and pisiform.

Gives a deep palmar branch, curves deep to the palmar aponeurosis but anterior to the long flexor tendons to form the superficial palmar arch

Anastomoses with the superficial palmar branch of the radial artery

Branches - 3 common palmar digital arteries branch off distally fro mthe convexity of the arch, dividing themselves in the proper palmar digital arteries to the fingers and 1 proper palmar digital artery to the little finger.

The deep branch of ulnar artery passes between the abductor digiti minimi and the flexor digit minimi brevis muscles to join radial artery

Front 3

Radial Artery swings from anterior to posterior by passing beneath the tendons of......

Back 3

both the abductor pollicis longus and extensor pollicis muslces (SNUFF BOX)

Front 4

Radial artery then dives deep to the palm of the hand, by diving between the the 2 heads of what? then it passes between what?

Back 4

1st dorsal interosseous muscle.

between the transverse and oblique heads of the adductor pollicis muscle

Front 5

Deep Palmar Arch forms by the anastomosis of what?

Does it run deep to long flexor tendons (the tendons coming from the elbow and further up)?
And is anterior to metacarpal bones and interosseous muscles?

Back 5

the radial artery with the deep branch of the ulnar artery to form the deep palmar arch.

yes
yes

Front 6

Deep Palmar Arch - how many small palmar metacarpal arteries anastomose with the matching arteries from the superficial arch?

Back 6

3. the deep palmar arch looks like the superficial palmar arch. those deep palmar metacarpal arteries come on up and attach to the superficial arteries

Front 7

As soon as the radial artery pass anterior over to posterior under Snuff Box tendons and around the thumb it reach the palm and gives what 2 arteries?

Back 7

Radialis indicis artery (supplies lateral side of index finger)

and

Princeps pollicis artery (which divides in two to supply the lateral and medial sides of thumb)

Front 8

Allen's Test - What's it test for?

Back 8

used to test blood supply to the hand

* Step 1 occludes the radial artery for several minutes and compares the hand color to the other hand. The hand is said to have sufficient collateral circulation through the ulnar artery if there is no change in color.

* Step 2 occludes the ulnar artery. A change in hand color means the potential for radial artery occlusion is high. That is a positive Allen's test, which contraindicates radial-artery puncture

Front 9

Cutaneous innervation of hand is by what nerves?

Back 9

radial, median, and ulnar

Front 10

Motor innervation of hand is by what nerves?

Back 10

median and ulnar

Front 11

Median nerve passes between what muscles of the forearm (at the location of the wrist)?

Does it pass under flexor retinaculum?

Note that the Median nerves gives a motor recurrent branch to the 3 muscles of the thenar eminence.

Back 11

flexor digitorum superficialis and the flexor carpi radialis

yes

Thenar eminence (compartment) - abductor pollicis brevis, flexor pollicis brevis, and opponens pollicis

Front 12

Does median nerve provide cutaneous innervation?

2 common palmar digital branches also come from medial nerve and they divide into proper palmar digital branches that innervate what?

Back 12

Yes, its called proper palmar digital nerves which innervate thumb and index finger.

index finger, middle finger and ring finger.

Front 13

What motor innervates the 1st lumbrical muscle?

What motor innervates the 2nd lumbrical muscle?

Back 13

proper palmar digital nerve

the common palmar digital nerve (page 475)

Front 14

Ulnar nerve - runs superficial to flexor retinaculum but runs distally in a groove between......

Back 14

the pisiform and the hook of hamate
*Note a small band of fibrous tissue closes this groove and forms a tunnel (the tunnel of Guyon) which the ulnar nerve can sometimes be compressed

Front 15

Does ulnar nerve have superficial and deep layers?

What does the superficial layer innervate?

What does the deep layer innervate?

Back 15

yes

Motor to palmaris brevis
Cutaneous to to the medial aspect of the medial 1 1/2 fingers

The 3 hypothenar muscles, all dorsal and palmar interossei muscles, and 2 most medial lumbrical muscles and the adductor pollicis muscle

*Note that the deep branch nerves can be found running with the deep arterial palmar branch in the palm.

Front 16

What happens when there is severe compression of the tunnel of Guyon?

Back 16

The tunnel of Guyon is where the Ulnar nerve passes through

Patients will lose cutaneous innervation to the palmar aspect of their medial 1 1/2 fingers, and lose the ability to contract all the intrinsic muscles of the hand (motor innervation to palmaris brevis, the 3 hypothenar muscles (abductor digiti minimi, flexor digiti minimi, opponens minimi), all dorsal and palmar interossei muscles, the 2 most medial lumbrical muscles and the adductor pollicis), except for the 5 muscles innervated by the median nerve

Front 17

If ulnar nerve is injured at the tunnel of Guyon, will both the flexor and extensor extrinsic muscles be unopposed?

Back 17

YES

The fingers will looked CLAWED

Front 18

All interossei muscles are paralyzed in the case of the injury of the Ulnar nerve.

So what occurs with the MCP, PIP, and the DIP joints?

Back 18

MCP joint is extended

PIP and DIP joints are in flexion

Front 19

Why are the index and ring fingers not as affected as badly?

Back 19

Because the lumbrical muscles there are innervated by the median nerve and not the ulnar nerve.

Front 20

Although when ulnar nerve injury happens at the tunnel of Guyon and the adductor pollicis muscles is non-functional and you can't adduct your thumb and hold on to stuff, you can still use your flexor pollicis brevis to flex thumb to touch your index finger.

Back 20

Flexor pollicis brevis won't be affected by ulnar nerve injury because its innervated by the median nerve

Front 21

What would happen if the ulnar nerve injury happened behind the medial epicondyle of the humerus?

Back 21

the ulnar half of the FDP would also be paralyzed in the forearm.

The flexor carpi ulnaris would also be paralyzed.

If the injury of ulnar nerve occurs higher like in arm than wrist, then the patient will present with less clawing of the little fingers.

Front 22

What muscles in the hand does the Median Nerve innervate?

Back 22

Abductor pollicis longus, flexor pollicis longus, and the 3 muscles of the thenar eminence (Abductor pollicis brevis, Flexor pollicis brevis, Opponens pollicis)

and the first 2 lumbrical muscles

Front 23

How does median nerve provide cutaneous innervation in the hand?

Back 23

Through 2 common palmar digital branches of median nerve (they innervate the first 2 lumbricals and cutaneous to lower palm)


and

The common palmer digital branch of the median nerve divide to give you the proper palmar digital nerves which give cutaneous innervation to the thumb, index, middle, and lateral 1/2 of ring finger.

Front 24

C4 (dermatome)

Back 24

Skin of shoulder

Front 25

C5 (dermatome)

Back 25

Skin of the lateral part of the arm

Front 26

C6 (dermatome)

Back 26

Skin of the thumb and lateral part of the forearm

Front 27

C7 (dermatome)

Back 27

skin of the index, middle finger and ring fingers, and middle part of the hand

Front 28

C8 (dermatome)

Back 28

Skin of the little finger, medial hand, and distal portion of the forearm

Front 29

T1 (dermatome)

Back 29

Skin of the medial side of the elbow joint, proximal forearm and distal arm

Front 30

T2 (dermatome)

Back 30

Skin of the axilla and medial side of the proximal arm