SM_229a: Functional Anatomy of the Hand Flashcards
The ulna articulates with the _____
The ulna articulates with the trochlea of the humerus
Radius articulates with the ____ of the humerus
Radius articulates with the capitulum of the humerus
Label the relevant landmarks on a right elbow AP x-ray
Label the bones of the right wrist
Trapezium articulates with the ____
Trapezium articulates with the thumb
____ has a rounded head
Capitate has a rounded head
Hamate has a ____, which defines the ____
Hamate has a hook, which defines the carpal tunnel
Most common fractures of the wrist are the _____ and _____
Most common fractures of the wrist are distal radius and scaphoid
(occur from breaking a fall with an outstretched hand)
Colles fracture of the radius involves a _____ deformity
Colles fracture of the radius involves a dinner fork deformity
(distal segment displaced dorsally)
Scaphoid fracture may lead to _____ in the proximal segment
Scaphoid fracture may lead to avascular necrosis in the proximal segment
If you can see both the radius and ulna when a scaphoid fracture is imaged, the orientation is _____
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
Describe the ligaments and articular disc of wrist joint
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
Describe the important muscles of the forearm
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)
During pronation/supination, head of the ____ pivots on the ____ of the humerus
During pronation/supination, head of the radius pivots on the capitulum of humerus
(pronator quadratus goes from radius to ulna)
Muscles on deep group of the forearm are ____, ____, and ____
Muscles on deep group of the forearm are flexor pillicis longus, flexor digitorum profundus, and pronator quadratus
Palmar aponeurosis is a ____ that functions to ____
Palmar aponeurosis is a broad flat tendon that functions to strengthen group
(distal attachment is to tendon sheaths)
____ branch of the ____ nerve is the motor branch to the thenar compartment and is superficial and susceptible to injury
Recurrent branch of the median nerve is the motor branch to the thenar compartment and is superficial and susceptible to injury
Dupuytren contracture is when the _____ contracts with fibrosis and fingers become _____ over time
Dupuytren contracture is when the palmar aponeurosis contracts with fibrosis and fingers become flexed over time
____ nerve passes through the carpal tunnel with the long flexor tendon
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)
In carpal tunnel syndrome, repetitive use of fingers results in swelling of _____ and compression of the _____ nerve, causing loss of or decreased _____ function
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
Synovial sheaths function to _____
Synovial sheaths function to reduce friction
Fibrous tendon sheaths function to _____ and _____
Fibrous tendon sheaths function to anchor the tendons and act as pulleys
_____ of digit _____ is continuous with the common flexor sheath at the wrist
Synovial sheath of digit V is continuous with the common flexor sheath at the wrist
____ are discontinuous mesotendons
Vincula are discontinuous mesotendons
Common sheath wraps the _____ and _____ tendons
Common sheath wraps the superficialis and profundus tendons
____ is an extensor seen in the posterior view of the right forearm
Extensor digitorum is an extensor seen in the posterior view of the right forearm
____ is in the anatomical snuff box
Radial artery is in the anatomical snuff box
In anatomical position, _____ of the thumb is a pure lateral movement
In anatomical position, extension of the thumb is a pure lateral movement
_____ of the thumb is a straight anterior movement
Abduction of the thumb is a straight anterior movement
Describe intrinsic muscle functions around the anterior-posterior axis at MC joints
Intrinsic muscle functions around the anterior-posterior axis at MC joints\
- Dorsal interossei abduct
- Palmar interossei adduct
- Lumbricals radially deviate
Dorsal interossei ____ at the ____ joints
Dorsal interossei abduct at the MC joints
Palmar interossei ____ at the ____ joints
Palmar interossei adduct at the MC joints
Lumbricals ____ at the ____ joints
Lumbricals radially deviate at the MC joints
____ and ____ are intrinsic muscles that attach to extensor hoods/expansions and ____ at MC joints and ____ at IP joints
Interosseous muscles and lumbricals are intrinsic muscles that attach to extensor hoods/expansions and flex at MC joints and extend at IP joints
____ palmar arch is a larger source of blood than the ____ palmar arch
Superficial palmar arch is a larger source of blood than the deep palmar arch
Deep palmar arch has connection to the _____ through the snuff box
Deep palmar arch has connection to the radial artery through the snuff box
_____ and _____ are potential spaces with loose CT
Thenar space and midpalmar space are potential spaces with loose CT
(lumbricals are on radial side of each tendon)
Ulnar nerve innervates ____ and ____
Ulnar nerve innervates flexor carpi ulnaris and 1/2 flexor digitorum profundus
(dorsal and palmar interossei: intrinsic muscles of the hand - delicate hand movement)
Median nerve innervates the ____ of the hand
Median nerve innervates the flexor muscles of the hand
Radial nerve innervates the _____ of the hand
Radial nerve innervates the extensor muscles of the hand
Musculocutaneous nerve is the ____ nerve of the ____
Musculocutaneous nerve is the lateral cutaneous nerve of the forearm
Digit ___ divides ulnar and median nerve territories
Digit IV divides ulnar and median nerve territories
Median cutaneous nerve of the forearm comes off the ____
Median cutaneous nerve of the forearm comes off the brachial plexus
Describe what occurs in deficit of the median nerve
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)
Describe what occurs in deficit of the ulnar nerve
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)
Describe what occurs in deficit of the radial nerve
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
Ape hand is indicative of deficit of the _____ nerve
Ape hand is indicative of deficit of the median nerve
(adducted thumb with supinated, extended wrist and extended fingers - except the ulnar 2)
Claw hand is indicative of deficit of the _____ nerve
Claw hand is indicative of deficit of the ulnar nerve
(abducted thumb with extended MCP joints and flexed IP joints)
Wrist drop is indicative of deficit of the _____ nerve
Wrist drop is indicative of deficit of the radial nerve nerve
(wrist flexed, forearm pronated)
Superficial palmar arch is a continuation of the ____ artery
Superficial palmar arch is a continuation of the ulnar artery
Deep palmar arch is a continuation of the ____
Deep palmar arch is a continuation of the radial artery
Venous drainage of the hand begins in the ____
Venous drainage of the hand begins in the dorsal plexus
(cephalic vein goes deep into deltopectoral triangle)
Summarize important concepts regarding the hand
Damage to the ulnar nerve leads to loss of _____
Damage to the ulnar nerve leads to loss of adduction of the digits
Fracture of the ____ would diminish extension of the elbow joint
Fracture of the olecranon process would diminish extension of the elbow joint
Widespread infection of synovial tendon sheaths within the carpal tunnel could result from a cut to digit ____
Widespread infection of synovial tendon sheaths within the carpal tunnel could result from a cut to digit V
Fracture of the ____ would make thumb movements painful via its articulation with the thumb metacarpal bone
Fracture of the trapezium would make thumb movements painful via its articulation with the thumb metacarpal bone
Laceration of the anterior boundary of the anatomical snuff box would diminish thumb extension and ____
Laceration of the anterior boundary of the anatomical snuff box would diminish thumb extension and thumb abduction
____ artery is the most significant source of blood to the hand
Ulnar artery is the most significant source of blood to the hand
____ bounds the cubital fossa medially
Pronator teres bounds the cubital fossa medially
A puncture wound to a muscle between the metacarpal bones on the back of the hand would impair _____
A puncture wound to a muscle between the metacarpal bones on the back of the hand would impair abduction of the digits
