FABS Quiz 5

What cutaneous nerve supplies the lateral half of the back of the hand?

Superficial branch and dorsal branches of radial nerve

What cutaneous nerve supplies the lateral side of fourth digit and palm?

Palmar digital branches of median nerve

What cutaneous nerve supplies medial side of fourth digit and palm?

Palmar digital branches of ulnar nerve

How many bones and articulations are in the hand?

19

How many muscles are in the hand?

29

What are the primary functions of the hand?

Support, manipulation, and prehension

What are the characteristics of manipulation of the hand?

repetitive and blunt, continuous and fluid

What are the characteristics of prehension?

Power grip

Precision grip

Power (Key) pinch

Precision pinch

Hook grip

Which digit has its own axis of rotation?

Thumb

Ab/adduction of the thumb is in what axis and plane?

x-axis and sagittal plane

Flex/extension of the thumb is in what axis and plane?

z-axis and coronal plane

Which tendon is missing in 30% of the population?

Palmaris longus

What makes the lateral border of the snuff box?

tendon of extensor pollicis brevis

What makes the medial border of the anatomical snuff box?

Tendon of extensor pollicis longus

Which artery is in the anatomical snuff box?

Radial

What makes the proximal transverse arch?

Proximal base carpal bones

What makes the distal transverse arch?

Distal row of carpal bones

What makes the longitudinal arch?

Third metacarpal, distal and medial carpal bones

What is continuous with the antebrachial fascia and fascia of the dorsum of the hand?

Dorsal fascia

What is the part of the deep fascia of the hand that covers the soft tissue and overlies the long flexor tendons?

Palmar aponeuroses

What are the muscles of the thenar compartment of the hand?

Abductor pollicis brevis

Flexor pollicis brevis

Opponens pollicis

What are the muscles of the hypothenar compartment of the hand?

Abductor digiti minimi

Flexor digiti minimi

Opponens digiti minimi

What are the muscles of the central compartment of the hand?

Lumbricals

Dorsal interossei

Palmar interossei

Adductor pollicis

All intrinsic muscles of the hand are innervated by what nerve?

Deep ulnar

All intrinsic muscles of the hand are innervated by the same nerve except for which muscles?

(1/2 LOAF) 1st/2nd lumbricals and the thenar muscles

O and I for the abductor pollicis brevis

O: flexor retinaculum and tubercles of the scaphoid and trapezium

I: Lateral side of base of proximal phalanx of thumb

A and N for the abductor pollicis brevis

A: Abducts thumb at CMC joint and assists the opponens pollicis

N: Recurrent branch of the median nerve (C8/T1)

O and I for the flexor pollicis brevis

O: flexor retinaculum and tubercles of the scaphoid and trapezium

I: Lateral side of base of proximal phalanx

A and N for the flexor pollicis brevis

A: Flexes thumb at the CMC and MCP joint and aids in opposition of thumb

N: Recurrent branch of median nerve

O and I for the opponens pollicis

O: flexor retinaculum and tubercles of the scaphoid and trapezium

I: Lateral side of first metacarpal

A and N for the opponens pollicis

A: Opposes the thumb

N: recurrent branch of median nerve

O and I for the adductor pollicis

O: Oblique head- bases of 2nd/3rd metacarpals, and adjacent carpals. Transverse head- anterior surface of body of 3rd metacarpal

I: Medial side of proximal phalanx of thumb

A and N for adductor pollicis

A: Adducts the thumb toward middle digit, moving thumb toward the palm

N: Deep branch of ulnar nerve

Where does the palmaris brevis lie and what does it overlie?

Lies in the subcutaneous tissue of hypothenar eminence

Overlies the ulnar nerve and artery at wrist

O and I for the palmaris brevis

O: Flexor retinaculum and palmar aponeurosis

I: Dermis of the ulnar border of the hand

A and N of the palmaris brevis

A: Contributes to grip by wrinkling and supporting of skin of the ulnar hand

N: Superficial branch of the ulnar nerve

O and I of the abductor digiti minimi

O: pisiform

I: Medial side of base of proximal phalanx of little finger

A and N of the abductor digiti minimi

A: abducts the 5th digit and helps flex its proximal phalanx

N: deep branch of the ulnar nerve

O and I of the flexor digiti minimi

O: hook of hamate and flexor retinaculum

I: Medial side of base of proximal phalanx of little finger

A and N for flexor digiti mini

A: flexes the proximal phalanx of the 5th digit at the MCP joint

N: Deep branch of the ulnar nerve

O and I for opponens digiti minimi

O: hook of hamate and flexor retinaculum

I: Medial border of 5th metacarpal

A and N for opponens digiti minimi

A: draws the 5th metacarpal anteriorly and rotates it laterally

N: deep branch of the ulnar nerve

Lumbricals 1 and 2 are what kind of muscles?

Unipennate

O and I for lumbricals 1 and 2

O: lateral two tendons of the FDP

I: Lateral sides of extensor expansions of 2nd and 3rd digits

A and N for lumbricals 1 and 2

A: flex the digits at the MCP joint and extend the IP joints

N: median nerve

What kind of muscles are lumbricals 3 and 4?

Bipennate

O and I for lumbricals 3 and 4

O: medial three tendons of the FDP

I: Lateral sides of extensor expansions of 4th and 5th digits

A and N for lumbricals 3 and 4

A: flex the digits at the MCP joint and extend the IP joints

N: deep branch of the ulnar nerve

What kind of muscles are the dorsal interossei 1-4?

Bipennate

O and I of the dorsal interossei 1-4

O: adjacent sides of two metacarpals

I: extensor expansions and bases of proximal phalanges of digits 2-4

A and N for dorsal interossei 1-4

A: abducts digits from the axial line and act with the lumbricals to flex the MCP joints and extend the IP joints

N: deep branch of the ulnar nerve

What kind of muscle is the palmar interossei?

Unipennate

O and I for palmar interossei

O: palmar surface of 2nd, 4th , and 5th metacarpals

I: extensor expansions of digits and bases of proximal phalanges of digits 2, 4, 5

A and N for palmar interossei

A: Adducts the digits toward axial line and assists the lumbricals in flexing the MCP joints and extending the IP joints

N: deep branch of ulnar

The tendons of the FDS and FDP enter what?

common flexor synovial sheath (ulnar bursa) deep to flexor retinaculum

Near the base of the proximal phalanx, what tendon splits and surrounds the tendon of the FDP?

Tendon of the FDS

What extends from the heads of the metacarpals to the bases of the distal phalanges? “Prevent bowstringing”

Fibrous digital sheaths

Which tendon passes deep to the flexor retinaculum within its own synovial sheath?

Tendon of the FPL

What artery enters the hand anterior to the flexor retinaculum between the pisiform and hook of hamate (Guyon’s canal)?

Ulnar artery

What is the area between the pisiform bone and hook of hamate?

Guyon’s canal

What two branches does the ulnar divide into?

Superficial palmar arch and deep palmar branch

Which artery curves dorsally around the scaphoid and trapezium in the floor of the anatomical snuffbox?

Radial

What structures does the radial artery pass between to enter the palm?

The heads of the 1st dorsal interosseous muscle

What the radial artery anastomoses with?

Deep palmar branch

What does the radial artery and deep palmar branch anastomoses to form?

deep palmar arch

The dorsal venous network (arch) gives rise to what two veins?

Basilic and cephalic

What are the contents of the carpal tunnel?

Median nerve, flexor pollicis longus tendon, flexor digitorum superficialis, flexor digitorum profundus

What makes up the borders of the carpal tunnel?

carpal arch and flexor retinaculum

How do you check for radiculopathy?

Check dermatomes, myotomes, and deep tendon reflex (DTR)

What is the DTR for C5?

Biceps tendon

What is the DTR for C6?

Brachioradialis

What is the DTR for C7?

Triceps tendon

What is the myotome for the deltoid and biceps?

C5

What is the myotome for the biceps, brachioradialis, and wrist extensor

C6

What is the myotome wrist flexor, finger extensor, and triceps?

C7

What is the cause of Erb-Duchenne’s palsy?

Injury to upper trunk (C5/C6)

What is the MOI that causes Erb-Duchenne’s?

Over stretch of upper trunk of brachial plexus due to fall

yanking on baby head at birth

Which affects of of Erb-Duchenne’s are partially?

Musculocutaneous nerve

What causes Klumpke’s palsy traction injuries?

Lower trunk injury of brachial plexus

What is the MOI of Klumpke’s palsy traction?

excessive abduction of the arm, presence of cervical rib, malignment metastasis from lungs in the lower deep cervical lymph nodes

What are the affects of Klumpke’s palsy traction?

Muscles of the distal forearm and hand, all ulnar-innervated muscles plus more distal radial and medial innervated muscles

What are the MOIs for injuring the axillary nerve?

crutch pressing into armpit, downward displacement of humeral head, fractures of surgical neck of humorous

What are the effects of an axillary nerve injury?

Teres minor and deltoid motor, shoulder joint, and skin over inferior part of deltoid sensory

What is the MOI for musculocutaneous nerve injury?

Rarely injured because protected position beneath biceps brachii

What are the affects of musculocutaneous nerve injury?

Muscles on anterior compartment of arm, forearm in pronation the ECRL and brachioradialis assist forearm flexion, and lateral aspect of skin of forearm

Radial nerve MOI

Using crutch, fracture shaft of humorous, Saturday night palsy

Injury affect in axilla and radial groove

Triceps, anconeus, and long extensors are paralyzed (Wrist drop)

Injury affect to deep radial nerve

fractures of proximal end of radius, dislocation of radial head, lost extension of fingers

MOI of median nerve

Injury at elbow or wrist

Affects of injury of median nerve

Pronator muscles, long flexors of wrist, loss of sensation of sympathetic control over skin