Anatomy of the hand

Question 1

What forms the roof of the carpal tunnel?

Answer 1

Flexor retinaculum

Question 2

What structures lie deep to the flexor retinaculum?

Answer 2

-Flexor digitorum superficialis and profundus muscle tendons
- Flexor pollicis longus muscle tendons
- Median nerve

Question 3

What structure passes through the flexor retinaculum?

Answer 3

Tendon of the flexor carpi radialis muscle

Question 4

What is the name of the triangular fascial layer on the palm, and what is its function?

Answer 4

Palmar aponeurosis

-Protects structures of the palm
-It is the point of insertion for the palmaris longus muscle.

Question 5

Describe the lumbricals in terms of their origin, insertion, innervation and action

Answer 5

Origin: tendons of the flexor digitorum profundus muscle

Insertion: Lateral sides of the extensor hoods

Innervation:
- Lateral two lumbricals by the median nerve
- Medial two lumbricals by the ulnar nerve

Action:
Flexion at the metacarpophalangeal joints
- Extends the dorsal interphalangeal joints

Question 6

Describe the abductor pollicis brevis muscle in terms of its origin, insertion, innervation and action

Answer 6

Origin:
Tubercle of the trapezium and scaphoid
- Adjacent flexor retinaculum

Insertion:
Proximal phalanx and extensor hood of thumb

Innervation:
- Recurrent branch of the median nerve

Action:
Abduction of the thumb at the metacarpophalangeal joint

Question 7

Describe the opponens pollicis muscle in terms of its origin, insertion, innervation and action

Answer 7

Origin
- Tubercle of the trapezium and the flexor retinaculum

Insertion
- Lateral margin and palmar surface of the 1st metacarpal

Innervation
- Recurrent branch of the median nerve

Action
Medially rotates the thumb

Question 8

Describe the adductor pollicis muscle in terms of its origin, insertion, innervation and action

Answer 8

Origin
Oblique head: Capitate and Bases of 2nd and 3rd metacarpals
Transverse head: Anterior surface of the shaft of the 3rd metacarpal

Insertion:
Base of the proximal phalanx of the thumb
Extensor hood of the thumb

Innervation
- Deep branch of the ulnar nerve

Action
Adducts the thumb

Question 9

Describe the abductor digiti minimi muscle in terms of its origin, insertion, innervation and action

Answer 9

Origin
- Pisiform and the pisohamate ligament
- Tendon of the flexor carpi ulnaris muscle
Insertion
- Proximal phalanx of the little finger
Action
- Abducts little finger at metacarpophalangeal joint
Innervation by the Deep branch of the ulnar nerve

Question 10

Describe the flexor digiti minimi muscle in terms of its origin, insertion, innervation and action

Answer 10

Origin
- Hook of the hamate and the flexor retinaculum
Insertion
- Proximal phalanx of the little finger
Action
- Flexes little finger at the metacarpophalangeal joint
Innervation
- Deep branch of the ulnar nerve

Question 11

Describe the opponens digiti minimi muscle in terms of its origin, insertion, innervation and action

Answer 11

Origin
- Hook of the hamate and the flexor retinaculum
Insertion
- Medial aspect of the 5th metacarpal
Action
- Laterally rotates of the 5th metacarpal
Innervation
- Deep branch of the ulnar nerve

Question 12

How many interosseous muscle does the hand have? how are they positioned?

Answer 12

There are 7 interosseous muscles.
-3 on the palmer side (2nd, 4th and 5th fingers), 4 on the dorsal side (2nd, 3rd and 4th fingers)

Question 13

Describe the palmer interosseous muscles in terms of their origin, insertion, innervation and action

Answer 13

• Origin
• Sides of the metacarpals
• Insertion
• Extensor hoods of the index, ring and little fingers
• Proximal phalanx of the index, ring and little fingers
• Action
• Adduction of the index, ring and little fingers
• Extension at the dorsal interphalangeal joints
• Innervation
• Deep branch of the ulnar nerve

Question 14

What is the name of the structure that lies over the tendons of the posterior compartment?

Answer 14

Extensor retinaculum

Question 15

Which muscle tendons are found in compartment 1?

Answer 15

Abductor pollicis longus muscle
- Extensor pollicis brevis muscle

Question 16

Which muscle tendons are found in compartment 2?

Answer 16

Extensor carpi radialis longus muscle
Extensor carpi radialis brevis muscle

Question 17

Which muscle tendons are found in compartment 3?

Answer 17

• Extensor pollicis longus muscle

Question 18

Which muscle tendons are found in compartment 4?

Answer 18

• Extensor digitorum muscle
• Extensor indicis muscle

Question 19

Which muscle tendons are found in compartment 5?

Answer 19

• Extensor digiti minimi muscle

Question 20

Which muscle tendons are found in compartment 6?

Answer 20

Extensor carpi ulnaris muscle

Question 21

Describe the dorsal interosseous muscles in terms of its origin, insertion, innervation and action

Answer 21

• Origin
• Adjacent metacarpals
• Insertion
• Extensor hoods of the index, ring and middle fingers
• Proximal phalanx of the index, ring and middle fingers
  Action
• Abduction of the index, ring and middle fingers
• Extension at the dorsal interphalangeal joints
• Innervation
• Deep branch of the ulnar nerve

Question 22

What is an extensor hood?

Answer 22

Tendons of the Extensor digitorum and extensor pollicis longus expand over the proximal phalanges to form a hood. This is called the extensor hood.

Question 23

Which muscles insert on the extensor hood?

Answer 23

• Middle 4 fingers
• Interossei and lumbricals

In the thumb
- The adductor pollicis and abductor pollicis brevis muscles insert

Question 24

Which muscles are innervated by the deep branch of the ulnar nerve? (5)

Answer 24

-Adductor pollicis muscle
-Abductor digiti minimi
-Flexor digiti minimi
-Opponens digiti minimi
-Interosseus muslces (both palmar and dorsal)
Two median lumbricals

Question 25

Which muscles are innervated by the recurrent branch of the median nerve? (3)

Answer 25

Abductor pollicis brevis muscle Flexor pollicis brevis muscle Opponens pollicis muscle Two lateral lumbricals

Question 26

Describe the brachial artery

Answer 26

It is the continuation of the axillary artery. It spans from the inferior border of the teres major muscle to the cubital fossa. Not superficial

Question 27

What branches does the brachial artery gives off?

Answer 27

Muscular branches - Deep artery of the arm - Superior and inferior ulnar collateral - Terminates as the radial and ulnar artery

Question 28

List the branches of the ulnar artery

Answer 28

Common interosseus - Anterior and posterior interosseus Anastomotic branches - Anterior and posterior ulnar recurrent collateral

Question 29

List the branches of the radial artery

Answer 29

Muscular branches - Anastomotic branches - Radial recurrent artery

Question 30

Describe the superficial palmar arch

Answer 30

Superficial palmar arch - Joining of ulnar and radial arteries - Contribution mainly by the ulnar artery

Question 31

Describe the deep palmar arch

Answer 31

Deep palmar arch - Joining of ulnar and radial arteries - Contribution mainly by the radial artery

Question 32

Describe the palmar digital arteries that arise from the superficial palmar arch

Answer 32

Superficial palmar arch - Gives off common palmar digital arteries - They terminate as proper palmar digital arteries - Palmar digital artery to medial side of the little finger

Question 33

Describe the palmar digital arteries that arise from the deep palmar arch

Answer 33

Deep palmar arch - Gives off palmar metacarpal arteries - Radialis indicis artery to the index finger - Princeps pollicis artery to the thumb

Question 34

Describe the dorsal digital arteries

Answer 34

Dorsal carpal arch is formed by the dorsal branches of radial and ulnar arteries - Gives off dorsal metacarpal arteries which terminate as dorsal digital arteries

Question 35

Where do the dorsal superficial veins commence?

Answer 35

They commence at the dorsal venous network

Question 36

What is formed from the dorsal venous network?

Answer 36

Basilic and cephalic veins

Question 37

Describe the cephalic vein

Answer 37

- Lies laterally - Lies superficial - Disappears in deltopectoral triangle - Drains into subclavian vein

Question 38

Where do the basilic and cephalic veins join? What joins them?

Answer 38

They join at the cubital fossa. Median cubital vein joins them

Question 39

Describe the deep veins

Answer 39

Have same names as arteries * From digital veins to palmar venous arches * Radial and ulnar * Brachial * Axillary * Subclavian * Brachiocephalic vein (With jugulars) * Superior vena cava

Question 40

What nerve does the median nerve give off in the cubital fossa?

Answer 40

Anterior interosseus nerve

Question 41

Which muscles are innervated by the anterior interosseus nerve?

Answer 41

Deep flexors - Flexor pollicis longus - Lateral half of Flexor digitorum profundus - Pronator quadratus

Question 42

The median nerve enters the palm via the____________________

Answer 42

carpal tunnel

Question 43

Which muscles of the hand are supplied by the median nerve?

Answer 43

Supplies thenar group and lateral 2 lumbricals

Question 44

The median nerve gives sensory innervation to ____________________

Answer 44

lateral 3 ½ fingers

Question 45

The __________ nerve runs over the flexor retinaculum at the wrist

Answer 45

Ulnar

Question 46

Explain the division of the ulnar nerve and what they innervate

Answer 46

Superficial branch - Skin on medial 1 ½ fingers on both surfaces * Deep branch innervates - Hypothenar - 2 medial lumbricals - All interossei - Adductor pollicis muscle

Question 47

What is innervated by the deep branch of the radial nerve? (post. interosseus nerve)

Answer 47

- Extensor carpi radialis brevis muscle - Supinator muscle - Extensor digitorum muscle - Extensor digiti minimi muscle - Extensor carpi ulnaris muscle - Extensor pollicis longus and brevis muscles - Extensor indicis muscle

Question 48

What is innervated by the superficial branch of the radial nerve?

Answer 48

Superficial innervates lateral 3 ½ of dorsum

Question 49

Intrinsic hand muscles

Answer 49

Thenar Hypothenar Lumbricals Adductor pollicis Palmar interosseous Dorsal interosseous

Question 50

Thenar muscles

Answer 50

AFO -Abductor pollicis brevis -Flexor pollicis brevis -Opponens pollicis

Question 51

Hypothenar mucsles

Answer 51

AFO Abductor digiti minimi Flexor digiti minimi Opponens digiti minimi

Question 52

Where do lumbricals arise from?

Answer 52

FDP (flexor digitorum profundus) tendon

Question 53

Palmar interosseous

Answer 53

PAD (adduct)

Question 54

Dorsal interosseous

Answer 54

DAB (abduct)