Lecture 8-- Hand

Question 0

What do you see in carpal tunnel

Answer 0

Since the median nerve is mainly responsible for innervation many of the thumb muscles, in carpal tunnel you see atrophy in the thenar eminence. They maintain some sensation over the palm of the hand because there is a branch of the median nerve that comes off before the carpal tunnel that provides sensation to the median distribution area of the hand.

Question 1

What nerve Innervates the thenar muscles

Answer 1

The recurrent branch of the median nerve except the adductor pollicis which is the deep branch of the ulnar nerve.

Question 2

What is unique about the thenar muscles

Answer 2

Abductor pollicis brevis and flexor pollicis both cross the MCP joint. The opponens pollicis inserts into the metacarpal so the fibers don’t cross the joint. Also this is the recurrent branch of the median nerve and it goes in between these two muscles.

Question 3

Describe the webspace of the hand

Answer 3

On the palmar side the first webspace is the adductor pollicis if you flip over to the dorsal side it’s the first dorsal interossei.

Question 4

The hypothenar muscles are all Innervated by what nerve

Answer 4

Deep branch of ulnar nerve

Question 5

The flexor digiti minimi brevis is ____ to the abductor digiti minimi

Answer 5

Lateral

Question 6

What are the short muscles Innervated by

Answer 6

The deep branch of the ulnar nerve except for lumbricals 1 and 2 which are the lateral and medial branches of the median nerve.

Question 7

If you lose your ulnar nerve behind the medial epicondyle with an elbow fracture, will you still have flexion in digits four and five?

Answer 7

Yes, because flexor digitorum superficialis. You would not have flexion at the dips because you lose the FDP and would have some flexion at MCP and PIP because you still have the FDS.

Question 8

What is the main contributor to the superficial palmar arch

Answer 8

The ulnar artery

Question 9

Goes behind or around the trapezium, scaphoid, and first metacarpal. It enters the palm by passing the heads of the first dorsal intrrossei. It turns medial and passes between the heads of the adductor pollicis.

Answer 9

Radial artery

Question 10

What is the main thing that forms the deep palmar arch

Answer 10

Radial artery

Question 11

What are the terminal branches of the radial artery

Answer 11

Dorsal carpal arch (dorsal metacarpal–>dorsal digital)
Superficial branch (superficial palmar arch)
Deep palmar arch (palmar metacarpal–> common palmar digital)
Princeps pollicis off deep arch
Radialis indicis off deep arch

Question 12

Enters the hand through the carpal tunnel. Gives off a recurrent branch in the thenar compartment and splits lateral and medial branches to the lumbricals.

Answer 12

Median nerve

Question 13

Distribution of the median nerve

Answer 13

Motor to the thenar muscles except The adductor pollicis and half of the flexor pollicis brevis–deep head–both deep branch of ulnar nerve. And lumbricals one and two

Sensory: Palm and dorsum (from dip and ip joints distal) of the hand lateral to the line bisecting the 4th digit

Question 14

What would you see if the median nerve was compressed in carpal tunnel syndrome

Answer 14

Loss of sensory not in the palm but out in the digits and loss of the thenar eminance. You have the adductor pollicis and all the muscles supplied by the radial and ulnar nerves and the flexor pollicis longus. Which means you can do enough flexion to do opposition. So you have weakening of actions but not atrophy.

Question 15

What would happen if you compress the ulnar nerve in guyon’s canal

Answer 15

Claw hand, you would notice its opposite of the Z motion. It is extension at the MCPs and flexion at the IPs instead of the opposite. Much worse in the fourth and fifth digits, but we see it in others as well because it Innervates the interossei. It’s called klumpke’s palsy and gets rid of c8 and t1. There is an imbalance between the remaining flexors and extensors. Whether it happens at the brachial plexus, elbow, or hand it will be this. If at elbow or above you get the FDP and FCU knocked out and no ulnar deviation. Lumbricals 2 and 3 are supplied by the median nerve

Question 16

The superficial radial branch of the radial nerve gives off what branch

Answer 16

The dorsal digital branches

Question 17

Distribution of the superficial branch of the radial nerve

Answer 17

Sensory to the dorsum of the hand lateral to a line bisecting the 4th digit from the dip and ip joints proximal

Question 18

Describe the regions of the hand

Answer 18

Central: between the palmar aponeurosis and the intermuscular septum
Thenar: base of the thumb
Hypothenar: over 5th metacarpal
Adductor-interossei: includes the muscles that make up the deep palm and the dorsum of the hand.
Dorsum: thin superficial fascia and deep fascia in which the dorsal venison network lies.

Question 19

What is contained in the central region of the hand

Answer 19

tendons of FDS, FDP, AND FPL. lumbricals, superficial and deep palmar arches, and median and ulnar nerves.

Question 20

What does the thenar region of the hand contain

Answer 20

Tendon of FPL, thenar muscles except the adductor pollicis, and the recurrent branch of the median nerve.

Question 21

What is contained in the hypothenar compartment of the hand

Answer 21

Contains the hypothenar muscles and the deep branch of the ulnar nerve.

Question 22

What is contained in the dorsum region of the hand

Answer 22

TENDONS OF ED, EI, EDM, EPB, AND EPL, and the dorsal carpal arterial arch and branches.

Question 23

The ____ encircles the head of the radius, holding in position on the ulna

Answer 23

Annular ligament

Question 24

The wrist is a what kind of joint

Answer 24

Condyloid

Question 25

What are the ligaments of the wrist joint

Answer 25

Palmar radiocarpal
Dorsal radiocarpal
Ulnar collateral
Radial collateral

Question 26

What are the articulations in the wrist joint

Answer 26

Intercarpal
Carpometacarpal
Intermetacarpal
Metacarpophalangeal