Lecture 13: Hand Flashcards
What does the radial nerve supply in the hand?
no muscles, only sensory
What does the palmar cutaneous branch of the median nerve supply?
central palm
Where does the palmar cutaneous branch of the median nerve arise from?
proximal to the flexor retinaculum
Where does the palmar cutaneous branch of the median nerve pass?
superficial to the flexor retinaculum
Where does the palmar cutaneous branch of the ulnar nerve arise from?
proximal to wrist
Where does the palmar cutaneous branch of the ulnar nerve pass?
superficial to flexor retinaculum and palmar aponeurosis
What does the palmar cutaneous branch of the ulnar nerve supply?
medial side of palm
What type of joint is the carpometacarpal joints
plane synovial
saddle joint between metacarpus and trapezium
What is the motion for the carpometacarpal joints for digits 2-3?
almost none
What is the motion for the carpometacarpal joints for digit 4?
limited
What is the motion for the carpometacarpal joints for digit 5?
more mobile: abduction/adduction
flexion/extension
circumduction/opposition
What is the vascularization of the carpometacarpal joints?
arterial anastomoses of dorsal and palmar carpal arches, deep palmar arch, and metacarpal arteries
What is the innervation of the carpometacarpal joints?
anterior interosseous branch of median nerve, posterior interosseous branch of radial nerve and dorsal/deep branches of ulnar nerve
What type of joint is the metacarpophalangeal joint?
condyloid synovial joints
What movement does the metacarpophalangeal joint do?
flexion/extension
abduction/adduction
some opposition at MCP 5
What capsular ligaments do the metacarpophalangeal joint have?
palmar ligaments
collaterals
What is the vascularization of the metacarpophalangeal joint?
deep digital arteries from superficial palmar arch
What is the innervation of metacarpophalangeal joint
digital nerves from ulnar and median nerves
Collateral ligaments are _____ during extension, ____ during flexion
slack; taut
What type of joint is the interphalangeal joint?
synovial hinge joint
What is the motion of interphalangeal joint?
flexion/extension
What are the ligaments of the interphalangeal joint?
strong collateral
What are the types of interphalangeal joints?
proximal interphalangeal joints (PIPs)
distal interphalangeal joints (DIPs)
What is the vascularization of the interphalangeal joint?
deep Digital arteries from superficial palmar arch
What is the innervation of the interphalangeal joint?
digital nerves from ulnar and median nerves
What is the palmar aponeurosis?
triangular layer of deep fascia located between two eminences
What does the palmar aponeurosis do?
provides protection for superficial vessels, nerves, and tendons
What is the palmar aponeurosis anchored to?
skin and flexor retinaculum
What does the flexor retinaculum attach to laterally?
tubercles of scaphoid and trapezium
What does the flexor retinaculum attach to medially?
hook of hamate and pisiform
palmaris brevis origin
flexor retinaculum and palmar aponeurosis
palmaris brevis insertion
skin on medial side of palm
palmaris brevis action
tenses skin on palm
What are the contents of the carpal tunnel?
long flexor tendons of:
flexor digitorum superficialis and profundus
flexor pollicis longus
median nerve
What do the ulnar nerve and artery pass through?
Guyon’s canal
Where is the thenar space?
located between palmar side of the adductor pollicis muscle and the long flexor tendons to the index finger and the thumb
Where is the midpalmar space?
located between metacarpals 4-5 and long flexor tendons to digits 4-5
Extensor indicis proximal attachment
posterior surface of distal 1/3 of ulna and interosseous membrane
Extensor indicis distal attachment
extensor expansion of second finger (index finger)
Extensor indicis actions
independent extension of 2nd finger but also helps with extension of the wrist
Extensor indicis blood supply
posterior interosseous artery and perforating branch of anterior interosseous artery
Extensor indicis innervation
posterior interosseous nerve (C7, 8)
What are the muscles of the thenar eminence?
abductor pollicis brevis
flexor pollicis brevis
opponent pollicis
What is the innervation of the thenar eminence?
recurrent branch of median nerve (C8, T1)
Adductor pollicis innervation
deep branch of ulnar nerve (C8, T1)
Opponens pollicis proximal attachment
flexor retinaculum and tubercles of scaphoid and trapezium
Opponens pollicis distal attachment
lateral side of 1st metacarpal
Opponens pollicis actions
oppose thumb and medially rotate 1st metacarpal
Opponens pollicis blood supply
radial artery
Opponens pollicis innervation
recurrent branch of median nerve (c8, T1)
Abductor pollicis brevis proximal attachment
flexor retinaculum and tubercles of scaphoid and trapezium
Abductor pollicis brevis distal attachment
lateral side of base of proximal phalanx of thumb
Abductor pollicis brevis actions
abduct thumb, aid in opposition
Abductor pollicis brevis innervation
recurrent branch of median nerve (C8, T1)
Flexor pollicis brevis origin
flexor retinaculum and tubercles of scaphoid and trapezium
Flexor pollicis brevis insertion
lateral side of base of proximal phalanx of thumb
Flexor pollicis brevis actions
flexes thumb
Flexor pollicis brevis blood supply
radial artery
Flexor pollicis brevis innervation
superficial head: recurrent branch of median nerve (c8, T1) and deep head: deep branch of ulnar nerve (C8, T1)
Adductor pollicis origin
bases of second and third metacarpals (oblique head)
capitate, and adjacent carpals (transverse head)
Adductor pollicis insertion
medial side of base of proximal phalanx of thumb
Adductor pollicis action
adducts thumb toward lateral border of palm
Adductor pollicis blood supply
radial artery
Adductor pollicis innervation
deep branch of ulnar nerve (C8, T1)
Muscles of hypothenar eminence
abductor digiti minimi
flexor digiti minimi brevis
opponens digiti minimi
innervation of hypothenar eminence
ulnar nerve
Abductor digiti minimi origin
pisiform
Abductor digiti minimi insertion
medial side of base of proximal phalanx of fifth digit
Abductor digiti minimi actions
abducts fifth digit, aids in flexion of with proximal phalanx
Abductor digiti minimi blood supply
ulnar artery
Abductor digiti minimi innervation
deep branch of ulnar nerve (c8, T1)
Flexor digiti minimi brevis origin
hook of hamate and flexor retinaculum
Flexor digiti minimi brevis insertion
medial side of base of proximal phalanx of fifth digit
Flexor digiti minimi brevis actions
flexes proximal phalanx of fifth digit
Flexor digiti minimi brevis blood supply
ulnar artery
Flexor digiti minimi brevis innervation
deep branch of ulnar nerve, C8 and T1
Opponens digiti minimi origin
hook of hamate and flexor retinaculum
Opponens digiti minimi insertion
medial border of 5th metacarpus
Opponens digiti minimi actions
brings fifth metacarpal anterior and rotates it to bring it into opposition with thumb
Opponens digiti minimi blood supply
ulnar artery
Opponens digiti minimi innervation
ulnar nerve deep branch, C8, T1
What does the flexor digitorum superficialis do?
flexes PIP and MCP and wrist
Each tendon of the flexor digitorum superficialis does what?
passes through fibrous flexor sheath
bifurcates opposite proximal phalanx
inserts on middle phalanx
What does the flexor digitorum profundus do?
flexes DIP and PIP and MCP
Each tendon of the flexor digitorum profundus inserts on what?
distal phalanx
What are vinculae?
small vascular bundles connecting palmar surface of phalanges with long flexor tendons
Dorsal interossei (DAB) are what?
four bipinnate muscles
Where does DAB arise from?
via two heads from adjacent sides of two metacarpals
What is the insertion of DAB?
onton extensor expansions and radial sides of proximal phalanges 2 and 3
ulnar sides of proximal phalanges 3 and 4
Action of DAB?
abduct MP joints of digits 2-4
What innervates all interossei?
ulnar nerve
What are palmar interssei (PAD)?
four unipennate muscles
What do PAD supply?
each digit except for third
Where does PAD insert?
onto ulnar sides of proximal phalanges 1 and 2
onto radial rides of proximal phalanges 4 and 5
PAD action
adduct MP joints of digits 1,2,4,5
What are the lumbricals?
four small, narrow, elongated muscles
Where do the lumbricalls arise from?
radial side of flexor digitorum profundus tendon
Lumbricalls innervation
two on radial side: median nerve
two on ulnar side: ulnar nerve
Lumbricalls action
flex MCP and extend IP joints
Where are the 1st and 2nd lumbricals attached?
lateral 2 tendons of FDP
What innervates the 1st and 2nd lumbricals?
median nerve (C8, T1)
Blood supply of the 1st and 2nd lumbricals?
radials indicis artery (radial artery) and superficial palmar arch (ulnar artery)
third and fourth lumbrical attachments
medial 3 tendons of FDP
third and fourth lumbrical innervation
deep branch of ulnar nerve (C8, T1)
third and fourth lumbrical blood supply
superficial palmar arch (ulnar artery) and dorsal carpal arch (ulnar and radial arteries)
Where do lumbricals insert?
lateral sides of the extensor expansions of digits 2-5
What is the arterial supply to the dorsum of the hand?
dorsal arterial arch from radial and ulnar arteries
dorsal metacarpal arteries
dorsal digital arteries
What is the venous drainage for the dorsum of the hand?
dorsal venous arch
medially drains into basilic
laterally drains into cephalic
What is the lymphatic drainage of the dorsum of the hand?
medial via lymph vessels accompanying basilic vein to supratrochearl nodes to lateral axillary nodes
The superficial palmar arch is a continuation of the _____ and the deep palmar arch is a continuation of the ______
ulnar artery; radial artery
Ulnar nerve enters hand _____ to flexor retinaculum
superficial
The superficial branch of the ulnar nerve supplies a muscular branch to
palmaris brevis
Deep branch of ulnar nerve supplies what?
hypothenar muscles, all interossei, two ulnar side lumbricals, and adductor pollicis
Median nerve enters palm ____ to flexor retinaculum
deep
Lateral branch of median nerve goes to what?
thenar muscles and first lumbrical
Medial branch of median nerve goes to what?
second lumbrical
What is mallet finger?
avulsion by long extensor tendon resulting in hyper flexion of DIP
What is Dupuytren’s contracture?
progressive fibrosis of palmar aponeurosis
results in marked flexion of fingers at MP joints
What is Colle’s fracture?
fracture in the distal end of the radius
more common in persons over the age of 50
What is fracture of the scaphoid?
most commonly fractured carpal bone
typically occurs at waist
What happens in median nerve injury?
loss of thumb opposition
atrophy of thenar muscles
ape hand
What happens in ulnar nerve injury?
paralysis and atrophy of interossei muscles
loss of thumb adduction
claw hand
What are the components to the extensor mechanism?
hood
lateral bands:bases to distal phalanges
central band: to base of middle phlanx
What is the function of the extensor mechanism?
flexion at MCP joints
extension at PIP, DIP joints
Extension of the PIP is always accompanied by the simultaneous ______ of the DIP
extension
When PIP is flexed, the DIP may be _____ or ______
extended or flexed
Extensor tendons form a moveable hood over the ____ and ____ joints of the fingers called the extensor expanision
MP and IP