thursday lecture Flashcards
Flexor Retinaculum
- spans area between pisiform, hamate, scaphoid, and trapezium
- transforms carpal arch into a tunnel
- Serves as attachent for thenar and hypothenar muscles
- helps hold down the flexor tensons (keeping things stable)
Guyon’s Canal
- where the ulnar nerve and artery run
- on ulnar side of the wrist
- Transverse carpal ligament and volar carpal ligament protect the nerve and artery
- frequent site of nerve entrapment
Palmar Fascia
- continuation of deep fascia
- thick, tendinous, triangular
Fibrous digital sheaths
synovial sheaths that enclose the flexor tendons as they pass along the palmar aspect of each digit
Metacarpophalangeal joint (MCP)
- Condyloid synoival joint
- heads of metacarpals with base of proximal phalanges
- joint capsule enclosing each joint
Metacarpophalangeal joint ligament
Collateral ligament
- passes posterior to joint for flexion and extension
- taut in 70-90 degrees of flexion (on slack at any less then these degrees)
Motions of the metacarpophalangeal joint
flexion extension abduction adduction circumduction of digits 2-5
Blood supply to the metacarpophalageal joint
deep digital arteries arising from superfical palmar arches
Interphalangeal joints
- hinge synovial joint
- heads of phalanges with bases of the more distal phalanges
- motion: flexion and extension
- blood supply: digital arteries
PIP and DIP joint ligament
-lateral and accessory collateral ligaments
(taut in 25 degrees flexion)
Carpometacarpal joint (CMC)
- thumb
- saddle synovial joint
- base of 1st metacarpal with trapzium
- capsule is loose
- 5 ligaments
the 5 ligaments of the CMC joint
- Radial and Ulnar collateral
- anterior and posterior oblique
- intermetacarpal
motions of the thumb
abduction adduction extension flexion opposition repositions
Thumb Metacarpophalangeal joint
- hinge joint
- resembles IP joint
- flexion and extension
- has collateral and palmar ligaments
Thenar Muscles
- under the thumb
- Abductor Pollicis Brevis
- Flexor Pollicis Brevis
- Opponens Pollicis
Opponens Pollicis origin
flexor retinaculum
Opponens Pollicis insertion
lateral side of 1st meetacarpal
Opponens Pollicis innervation
Recurrent branch of median nerve
Opponens Pollicis action
Oppose thumb
Abductor Pollicis brevis origin
flexor retinaculum (in the web of the thumb)
Abductor Pollicis Brevis insertion
lateral side of base of proximal phalanx of thumb
Abductor Pollicis Brevis innervation
Recurrent branch of median nerve
Abductor Pollicis Brevis action
abducts the thumb
Flexor Pollicis Brevis origin
flexor retinaculum
Flexor Pollicis Brevis insertion
lateral side of basse of proximal phalanx of thumb
Flexor Pollicis Brevis innervation
Recurrent Branch of median nerve
Flexor Pollicis Brevis action
flexes thumb
Hypothenar Muscles
- Abductor digiti minimi
- Flexor digiti minimi brevis
- Opponens digiti minimi
- under the pinky finger
Abductor digiti minimi origin
pisiform
abductor digiti minimi insertion
medial side of base of proximal phalanx of 5th finger
abductor digiti minimi innervation
deep branch of ulnar nerve
abductor digiti minimi action
abdcuts 5th digit
flexor digiti minimi brevis origin
hook of the hamate and flexor retinaculum
flexor digiti minimi brevis insertion
medial side of base of proximal phalanx of 5th finger
flexor digiti minimi brevis innervation
deep branch of the ulnar nerve
flexor digiti minimi brevis action
flexes 5th fingers
Opponens digiti minimi origin
hook of the hamate and flexor retinaculum
Opponens digiti minimi insertion
medial border of 5th metacarpal
Opponens digiti minimi innervation
deep branch of the ulnar nerve
Opponens digiti minimi action
draws the 5th digit and rotates it, to help it touch the tip of thumb
Muscles of the hand
Lumbricals and Interossei
Lumbricals 1,2,3,4 origin
1 and 2: lateral two tendons of flexor digitorum profundus
3 and 4: medial three tendons of flexor digitorum profundus
Lumbricals 1,2,3,4 insertion
all 4 the same: laterl sides of the extensor expansions
lumbricals 1,2,3,4 innervation
median nerve
lumbricals 1,2,3,4 action
- Flex MCP joint
- Extends both IP joints
“L” hands
dorsal interossei 1-4 origin
adjacent sides of two metacarpals
Dorsal interossei 1-4 insertion
bases of proximal phalages
extensor expansion of 2-5 digits
Dorsal interossei 1-4 innervation
Deep branch pf the ulnar nerve
Dorsal interossei 1-4 action
- DAB
- Abducts 2nd-4th fingers from the axial line
- acts with the lumbricals to flex MCP joint and extend IP joints
Palmar interossei 1-3 origin
Palmar surface of 2nd, 4th and 5th metacarpal
Palmar interossei 1-3 insertion
bases of proximal phalanges
extensor expansions of 2nd, 4th, and 5th fingers
Palmar interossei 1-3 innervation
deep branch of ulnar nerve
Palmar interossei 1-3 action
- PAD
- adducts 2nd, 4th, and 5th, finger towards the axial line
- acts with the lumbricals to flex MCP joint and extend IP joints
Ulnar artery
- enters anterior to flexor retinaculum in Guyon’s canal
- lateral to the ulnar nerve
- gives rise to the deep palmar branch and the superifical palmar arch (which has three digital arteries)
The three digital arteries of the superical palmar arch
- made by the ulnar artery
- common palmar
- palm metacarpal
- proper palmar digital
Route of the radial artery
- Curves dorsally around scaphoid and trapzium in the floor of the snuff box
- reaches palm by passing between head of first dorsal interossei
- turns medially and passes between heads of adductor pollicis
- the joins with the ulnar artery to form the deep palmar arch
Extensor Mechanism
- Complex network of ligamentous and muscular units that coorinate to product extension of the digits
- Interossei (Dorsal and Palmar)
- Lumbricals
- Oblique Retinacular ligament (ORL)
- Extensor digitorum
Extensor expansion what is it?
triangular tendinosis aponerosis wrapping around dorsum and sides of the metacarpal heads and base of proximal phalanx
Extensor digitorum hood
- splits into median bands and lateral bands
- anchored on the side by palmar ligamen
Oblique retinacular ligament
- taut during flexion of DIP and this puls the PIP into flexion
- extending the PIP joint pulls the DIP into exension
(When you pull of the DIP with the ORL it makes the PIP follow)
Mallet FInger
a finger stuck in a PIP joint that is flexed
Dupuytren Contracture
- common in men of eastern european descent who smoke
- fascia of the hand hardens and pulls of the fourth and fifth digit into extension
Tigger finger
Nodule of the long flexor tendon
