SM_229a: Functional Anatomy of the Hand

Question 1

The ulna articulates with the _____

Answer 1

The ulna articulates with the trochlea of the humerus

Question 2

Radius articulates with the ____ of the humerus

Answer 2

Radius articulates with the capitulum of the humerus

Question 3

Label the relevant landmarks on a right elbow AP x-ray

Answer 3

Question 4

Label the bones of the right wrist

Answer 4

Question 5

Trapezium articulates with the ____

Answer 5

Trapezium articulates with the thumb

Question 6

____ has a rounded head

Answer 6

Capitate has a rounded head

Question 7

Hamate has a ____, which defines the ____

Answer 7

Hamate has a hook, which defines the carpal tunnel

Question 8

Most common fractures of the wrist are the _____ and _____

Answer 8

Most common fractures of the wrist are distal radius and scaphoid

(occur from breaking a fall with an outstretched hand)

Question 9

Colles fracture of the radius involves a _____ deformity

Answer 9

Colles fracture of the radius involves a dinner fork deformity

(distal segment displaced dorsally)

Question 10

Scaphoid fracture may lead to _____ in the proximal segment

Answer 10

Scaphoid fracture may lead to avascular necrosis in the proximal segment

Question 11

If you can see both the radius and ulna when a scaphoid fracture is imaged, the orientation is _____

Answer 11

If you can see both the radius and ulna when a scaphoid fracture is imaged on CT, the orientation is coronal orientation

(if you only see the radius or the ulna) the CT is sagittal

Question 12

Describe the ligaments and articular disc of wrist joint

Answer 12

Ligaments and articular disc of wrist joint

• Annular ligament hold radius against ulna
• Interosseous membrane holds radius and ulna together
• Articular cartilage at end of radius continues

Question 13

Describe the important muscles of the forearm

Answer 13

Forearm

• Pronator teres is active in pronation
• Brachioradialis is anterior to axis and acts as flexor (strongest when forearm is halfway between flexion and extension)

Question 14

During pronation/supination, head of the ____ pivots on the ____ of the humerus

Answer 14

During pronation/supination, head of the radius pivots on the capitulum of humerus

(pronator quadratus goes from radius to ulna)

Question 15

Muscles on deep group of the forearm are ____, ____, and ____

Answer 15

Muscles on deep group of the forearm are flexor pillicis longus, flexor digitorum profundus, and pronator quadratus

Question 16

Palmar aponeurosis is a ____ that functions to ____

Answer 16

Palmar aponeurosis is a broad flat tendon that functions to strengthen group

(distal attachment is to tendon sheaths)

Question 17

____ branch of the ____ nerve is the motor branch to the thenar compartment and is superficial and susceptible to injury

Answer 17

Recurrent branch of the median nerve is the motor branch to the thenar compartment and is superficial and susceptible to injury

Question 18

Dupuytren contracture is when the _____ contracts with fibrosis and fingers become _____ over time

Answer 18

Dupuytren contracture is when the palmar aponeurosis contracts with fibrosis and fingers become flexed over time

Question 19

____ nerve passes through the carpal tunnel with the long flexor tendon

Answer 19

Median nerve passes through the carpal tunnel with the long flexor tendon

(ulnar artery is superficial)

(flexor retinaculum is connective tissue that holds down flexors and closes off the carpal tunnel)

Question 20

In carpal tunnel syndrome, repetitive use of fingers results in swelling of _____ and compression of the _____ nerve, causing loss of or decreased _____ function

Answer 20

In carpal tunnel syndrome, repetitive use of fingers results in swelling of synovial tendon and compression of the median nerve, causing loss of or decreased thumb function

Question 21

Synovial sheaths function to _____

Answer 21

Synovial sheaths function to reduce friction

Question 22

Fibrous tendon sheaths function to _____ and _____

Answer 22

Fibrous tendon sheaths function to anchor the tendons and act as pulleys

Question 23

_____ of digit _____ is continuous with the common flexor sheath at the wrist

Answer 23

Synovial sheath of digit V is continuous with the common flexor sheath at the wrist

Question 24

____ are discontinuous mesotendons

Answer 24

Vincula are discontinuous mesotendons

Question 25

Common sheath wraps the _____ and _____ tendons

Answer 25

Common sheath wraps the superficialis and profundus tendons

Question 26

\_\_\_\_ is an extensor seen in the posterior view of the right forearm

Answer 26

Extensor digitorum is an extensor seen in the posterior view of the right forearm

Question 27

\_\_\_\_ is in the anatomical snuff box

Answer 27

Radial artery is in the anatomical snuff box

Question 28

In anatomical position, _____ of the thumb is a pure lateral movement

Answer 28

In anatomical position, extension of the thumb is a pure lateral movement

Question 29

\_\_\_\_\_ of the thumb is a straight anterior movement

Answer 29

Abduction of the thumb is a straight anterior movement

Question 30

Describe intrinsic muscle functions around the anterior-posterior axis at MC joints

Answer 30

Intrinsic muscle functions around the anterior-posterior axis at MC joints\ * Dorsal interossei abduct * Palmar interossei adduct * Lumbricals radially deviate

Question 31

Dorsal interossei ____ at the ____ joints

Answer 31

Dorsal interossei abduct at the MC joints

Question 32

Palmar interossei ____ at the ____ joints

Answer 32

Palmar interossei adduct at the MC joints

Question 33

Lumbricals ____ at the ____ joints

Answer 33

Lumbricals radially deviate at the MC joints

Question 34

\_\_\_\_ and ____ are intrinsic muscles that attach to extensor hoods/expansions and ____ at MC joints and ____ at IP joints

Answer 34

Interosseous muscles and lumbricals are intrinsic muscles that attach to extensor hoods/expansions and flex at MC joints and extend at IP joints

Question 35

\_\_\_\_ palmar arch is a larger source of blood than the ____ palmar arch

Answer 35

Superficial palmar arch is a larger source of blood than the deep palmar arch

Question 36

Deep palmar arch has connection to the _____ through the snuff box

Answer 36

Deep palmar arch has connection to the radial artery through the snuff box

Question 37

\_\_\_\_\_ and _____ are potential spaces with loose CT

Answer 37

Thenar space and midpalmar space are potential spaces with loose CT (lumbricals are on radial side of each tendon)

Question 38

Ulnar nerve innervates ____ and \_\_\_\_

Answer 38

Ulnar nerve innervates flexor carpi ulnaris and 1/2 flexor digitorum profundus (dorsal and palmar interossei: intrinsic muscles of the hand - delicate hand movement)

Question 39

Median nerve innervates the ____ of the hand

Answer 39

Median nerve innervates the flexor muscles of the hand

Question 40

Radial nerve innervates the _____ of the hand

Answer 40

Radial nerve innervates the extensor muscles of the hand

Question 41

Musculocutaneous nerve is the ____ nerve of the \_\_\_\_

Answer 41

Musculocutaneous nerve is the lateral cutaneous nerve of the forearm

Question 42

Digit ___ divides ulnar and median nerve territories

Answer 42

Digit IV divides ulnar and median nerve territories

Question 43

Median cutaneous nerve of the forearm comes off the \_\_\_\_

Answer 43

Median cutaneous nerve of the forearm comes off the brachial plexus

Question 44

Describe what occurs in deficit of the median nerve

Answer 44

Median nerve deficit * Loss of sensation in its territory * Loss of thumb function and thenar atrophy * Ape hand: adducted thumb with supinated extended wrist and extended fingers (except ulnar 2) (lose thumb flexion so thumb adducted)

Question 45

Describe what occurs in deficit of the ulnar nerve

Answer 45

Ulnar nerve deficits * Loss of sensation in its territory * Claw hand: abducted thumb with extended MCP joints and flexed IP joints * Cannot hold paper between fingers (lose adductor hollicus so thumb abducted)

Question 46

Describe what occurs in deficit of the radial nerve

Answer 46

Radial nerve deficits * Loss of sensation in its territory * Wrist drop: wrist flexed, forearm pronated * Looks similar to waiter's tip upper brachial plexus injury

Question 47

Ape hand is indicative of deficit of the _____ nerve

Answer 47

Ape hand is indicative of deficit of the median nerve (adducted thumb with supinated, extended wrist and extended fingers - except the ulnar 2)

Question 48

Claw hand is indicative of deficit of the _____ nerve

Answer 48

Claw hand is indicative of deficit of the ulnar nerve (abducted thumb with extended MCP joints and flexed IP joints)

Question 49

Wrist drop is indicative of deficit of the _____ nerve

Answer 49

Wrist drop is indicative of deficit of the radial nerve nerve (wrist flexed, forearm pronated)

Question 50

Superficial palmar arch is a continuation of the ____ artery

Answer 50

Superficial palmar arch is a continuation of the ulnar artery

Question 51

Deep palmar arch is a continuation of the \_\_\_\_

Answer 51

Deep palmar arch is a continuation of the radial artery

Question 52

Venous drainage of the hand begins in the \_\_\_\_

Answer 52

Venous drainage of the hand begins in the dorsal plexus (cephalic vein goes deep into deltopectoral triangle)

Question 53

Summarize important concepts regarding the hand

Answer 53

Question 54

Damage to the ulnar nerve leads to loss of \_\_\_\_\_

Answer 54

Damage to the ulnar nerve leads to loss of adduction of the digits

Question 55

Fracture of the ____ would diminish extension of the elbow joint

Answer 55

Fracture of the olecranon process would diminish extension of the elbow joint

Question 56

Widespread infection of synovial tendon sheaths within the carpal tunnel could result from a cut to digit \_\_\_\_

Answer 56

Widespread infection of synovial tendon sheaths within the carpal tunnel could result from a cut to digit V

Question 57

Fracture of the ____ would make thumb movements painful via its articulation with the thumb metacarpal bone

Answer 57

Fracture of the trapezium would make thumb movements painful via its articulation with the thumb metacarpal bone

Question 58

Laceration of the anterior boundary of the anatomical snuff box would diminish thumb extension and \_\_\_\_

Answer 58

Laceration of the anterior boundary of the anatomical snuff box would diminish thumb extension and thumb abduction

Question 59

\_\_\_\_ artery is the most significant source of blood to the hand

Answer 59

Ulnar artery is the most significant source of blood to the hand

Question 60

\_\_\_\_ bounds the cubital fossa medially

Answer 60

Pronator teres bounds the cubital fossa medially

Question 61

A puncture wound to a muscle between the metacarpal bones on the back of the hand would impair \_\_\_\_\_

Answer 61

A puncture wound to a muscle between the metacarpal bones on the back of the hand would impair abduction of the digits