Palm Of The Hand Flashcards
Carpus
.wrist
. 8 carpal bones arranged in 2 rows of 4
Prox. Row of carpus from lateral to medial
. Scaphoid w/ tubercle
. Lunate
. Triquetral
. Pisiform
Distal row of carpus from lateral to medial
. Trapezium w/ tubercle
. Trapezoid
. Capitate
. Hamate w/ hook
Metacarpals
. Numbered I-V lat. to med.
. Has base, shaft, and head (distal)
. Bases articulate w/ distal row of carpals and each other (except I which only articulates w/ trapezium)
. Heads articulate w/ base of prox. Phalanges
Digits
. I-V lat. to med.
. II-V has 3 phalanges (prox., intermediate, distal)
. I has 2 phalanges (prox., distal)
. Distal phalanges have expanded tuberosities that support digital pads
Carpometacarpal (CM) joints
. Btw distal carpal row and metacarpal bases
Metacarpophalangeal (MP) joints
Btw metacarpal head and prox. Phalangeal bases
Proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints
Btw heads and based of adjacent phalanges
. Thumb only has 1 interphalangeal joint (IP)
Carpal groove
Deep groove formed by palmar concavity of carpus
Flexor retinaculum (transverse carpal ligament) and attachments
Fibrous specialization of deep fascia that bridges carpal groove
. Med. attachment: pisiform and hook of hamate
. Lat. attachment: tubercles of scaphoid and trapezium
Carpal tunnel
. Osseofibrous tunnel formed by carpal bones and flexor retinaculum
. Connects ant. Compartment of forearm and palm
Contents of carpal tunnel proper
. Tendons of extrinsic flexors (flexor digitorum, flexor digitorum profundus. And flexor pollicis longus mm.)
. Synovial tendon sheaths
. Median n.
Where does flexor carpi radialis m. Enter hand?
Separate compartment in lat. wall of carpal tunnel
T/F palm of hand lacks sebacous glands
T
T/F skin of palm of hand does not adhere to underlying deep fascia
F, tightly adherent to deep fascia to facilitate gripping
Flexion creases
. Reflect patterns of habitual joint movement
. Distal wrist crease
. Prox. Transverse crease
. Distal transverse crease
Distal wrist crease
Marks prox. Border of flexor retinaculum
Start fo carpal tunnel
Prox. Transverse crease
Med. end marks location of superficial palmar arterial arch
Distal transverse crease
Marks prox. Extend of distal synovial sheathes of digits II-IV
Dermatoglyphs
Fine ridges on digital pads that inc. friction and facilitate grasping
Simian crease
. Single transverse palmar crease
. Indicative of trisomy 21 but can occur in small number of general population
Thenar eminence
Lat. fleshy mass formed by intrinsic muscles of digit I
Hypothenar eminence
Med. fleshy mass formed by intrinsic muscles of digit V
Deep palmar fascia
.Continuous w/ deep fascia of forearm (antebrachial fascia)
. Thin over thenar and hypothenar eminences
. Thick over central palm and digits
Palmaris aponeurosis
. Triangular thickened fascia of central palm
. Lies superficial go long flexor tendons, nerves, and vessels entering palm
. Apex continuous proximally w/ flexor retinaculum and tendon of palmaris longus m.
Longitudinal digital bands
. Distal extensions of palmar aponeurosis
. Blend w/ fibrous digital sheaths of digits II-V
Medial and lateral intermuscular septa
. Extend from med. and lat. borders of palmar aponeurosis to attach to shafts of 3rd and 5th metacarpals
. Define central, thenar, and hypothenar compartments
Palmaris brevis m. OIAN
A: Wrinkles the skin of med. palm
. O: med. palmar aponeurosis and adjacent flexor retinaculum
I: skin of med. palm
. N: ulnar nerve (superficial branch)
Fibrous digital sheaths
. Specialization of deep fascia
. Attach along med. and lat. palmar margins of phalanges forming osseofibrous tunnels enclosing long flexor tendons and digital synovial sheaths
. Thickness and fiber orientation vary
. annular pulleys and cruciform pulleys
. Sheaths of II-V continuous proximally w/ longitudinal digital bands of palmar aponeurosis
Annular pulleys
. Thick, transversely oriented component of digital sheath
Cruciform pulleys
Thin, obliquely oriented component of digital sheath
Duputyren’s contracture
. Pathological fibrosis and shortening of palmar aponeurosis or longitudinal digital bands creases traction on the fibrous digital sheaths
. Flexors deformity of digits IV-V
Synovial tendon sheaths
. Thin-walled sacs lined by synovial membrane and containing thin layer of synovial fluid
Common flexor synovial sheath or ulnar bursa
. Common sheath enveloping tendons of flexor digitorum superficialis and flexor digitorum profundus mm.
. Begins prox. To flexor retinaculum
. Continuous distally w/ the digital synovial sheath of digit V
Synovial sheath of flexor pollicis longus/ radial bursa
. Lat. to the common synovial flexor sheath (communicates w/ it often)
. Begins prox. To flexor retinaculum
. Continuous distally w/ the digital synovial sheath of the thumb
Digital synovial sheaths
. Envelop flexor tendons w/ digital tendons
. Synovial sheaths of digits II-IV terminate prox. At the metacarpal midshaft
. Digits I and V continuous w/ radial and ulnar bursae
Vincula
Specialized synovial folds (mesotenons) connecting extrinsic flexor tendons to underlying bone and ligament
. Transmits small vessels
Bacterial tenosynovitis
. Caused by deep penetrating injuries
. Infections in digits I or V (radial/ulnar bursa) can spread rapidly to neighboring bursa and proximally to forearm
. Digits II-IV infections contained w/in digit
Plane of flexion/extension in digits
Sagittal plane
Abduction/adduction plane for digits
. Coronal plane
Medal/lateral rotation in digits
. Transverse plane
. Limited in 5th CM joint
. Occurs when cupping palm or opposing thumb and little finger
Digit I first CM joint properties
. 1st CM joint and palmar surface of thumb rotated medially
. Movements of thumb occur at right angles to those of the other digits
Flexion/extension in thumb
. Coronal plane
. Occurs at IP, MP, and CM joints
. Flexion of 1st CM contributes significantly to thumb flexion
Abduction in thumb
Move ant. Away from the plane of the palm
Adduction in thumb
. Movement post. Toward plane of palm
Opposition in thumb
. Compound movement involving flexion and abduction accompanied by med. rotation of 1st CM joint
. allows thumb tip to contact (oppose) tips of other digits
Reposition in thumb
. Return of the thumb to the neutral position
Extrinsic muscles of the palm
. Flexor digitorum superficial m.
. Flexor digitorum profundus m.
. Flexor pollicis longus m.
Intrinsic muscles of the palm groups
.thenar muscles
. Hypothenar muscles
. central compartment muscles
Thenar muscle characteristics
. Make up thenar eminence
. Share common origin from flexor retinaculum and its bony reattachments
. All innvervated by recurrent branch of median n.
Thenar muscle names
. Abductor pollicis brevis
. Flexor pollicis brevis
. Opponens pollicis m.
Abductor pollicis brevis IA
I: base of prox. Phalanx of the thumb
A: abducts thumb
Flexor pollicis brevis m. IA
I: base of prox. Phalanx of the thumb
A: flexes CM and MP joints of thumb
Opponens pollicis m. IA
I: lat. shaft of metacarpal
A: opposes thumb
Hypothenar muscle characteristics
. Intrinsic muscles of digit V
. Common origin from flexor retinaculum and its attachments
. Innervated by deep branch of ulnar n.
Hypothenar muscles names
. Abductor digiti minimi
. Flexor digiti minimi
. Opponens digiti minimi
Abductor digiti minimi IA
I: medial base of prox. Phalanx of digit V
A: abducts digit V
Flexor digiti minimi IA
I: base of prox. Phalanx of digit V
A: flexes MP joint of digit V
Opponens digiti minimi IA
I: shaft of metacarpal V
A: opposes digit V
Adductor pollicis m. OIAN
O: transverse head from shaft of metacarpal III, oblique head from capitate and bases of metacarpals II-III
I: med. base of prox. Phalanx of the thumb
A: adducts and flexes thumb
N: deep branch of ulnar n.
Palmar interosseous muscles number of them and OIAN
.3 muscles O: shafts of metacarpals II, IV, and V I: extensor expansions of digits II, IV, V A: adducts and flexes thumb N: deep branch of ulnar n.
Dorsal interosseous muscles number and OIAN
. 4 muscles
O: bipennate muscles originating from adjacent metacarpal shafts
I: prox. Phalangeal bases and extensor expansions of digits II-I
A: abduction, flexion of MP joints, extension of PIP and DIP joints
N: deep branch ulnar nerve
Lumbricals m. Number and OIAN
. 4 muscles
. O: tendons of flexor digitorum profundus m.
I: lat. side of extensor expansion of digits II-V
A: flexion of MP joints, extension of PIP and DIP joints, abduction of digits II-III, adduction of digits IV-V
N: lumbricals 1-2 by median n., 3-4 by deep branch of ulnar n.
Claw-hand deformity
. Lumbrical paralysis causes inadequately opposed extrinsic flexors draw the affected digit into a flexed position
T/F interossei and lumbricals all act to flex the MP joints and extend the IP joints
T
What muscles perform the flexing motion of MP joints while extending IP joints most effectively?
Lumbricals
Median n.
. Motor supply to 5 intrinsic muscles of the hand
. Innervation to lat. palm and lat. 3.5 digits
Median nerve pathway
. Enters palm throug carpal tunnel deep to flexor retinaculum
. Goes ant. To long flexor tendons
Median n. Branches and their pathways
. Palmar cutaneous branch: prox. To carpal tunnel, passes superficial to flexor retinaculum to supply lat. palm
. Recurrent median n.: deep to flexor retinaculum , courses proximolaterally to supply 3 thenar muscles
What occurs when you get a superficial laceration over the thenar eminence that severs recurrent median n.?
Loss of opposition, weakened thumb flexion and abduction
Atrophy of thenar muscles
Common palmar digital nn.
. Small branches give motor innervation to lumbricals 1-2
Proper palmar digital nn.
. Terminal branches of common palmar digital nn.
. Give cutaneous innervation to palmer surfaces and nail beds of the lat. 3.5 digits
Carpal tunnel syndrome
. Caused by edema or repetitive flexion/extension of wrist and fingers
. Compression. Of median n. W/in carpal tunnel
. Numbness and tingling in lat. 3.5 digits, weakness of thumb movements and clawing of digits 2-3
Ulnar n.
. Motor innervation to all other intrinsic hand muscles and cutaneous innervation to palmar and dorsal aspects of med. hand and 1.5 digits
Ulnar n. Pathway
. Ulnar n. Crosses the wrist in a groove btw pisiform and hook of hamate and superficial to flexor retinaculum
. Ligament bridging the groove creates an osseofibrous tunnel (ulnar Guyon’s canal) for ulnar nerve and vessels
Ulnar n. Branches and pathways
. Palmar cutaneous branch: arises in forearm and supplies skin of med. palm
. Dorsal cutaneous branch: arises in forearm, supplies skin of med. side of the dorsal aspect of the hand, gives dorsal digital branches to med. 1.5 digits
. Superficial branch: supplies palmaris brevis, common
. Deep branch: passes through hypothenar muscles mass to reach the deep palmar space, gives muscular branches to hypothenar muscles, lumbricals 3-4, interossei, and adductor pollicis m.
Common and proper palmar digital nn.
. Off of superficial branch of ulnar n.
. To palmar surfaces and nail beds of the med. 1.5 digits
To achieve full anesthesia of a finger local anesthetic must be injected on ____
Both sides (med. and lat.) of digital base
Cyclist’s palsy
. Numbness or tingling of med. 1.5 digits and weakness of intrinsic hand muscles
. Caused by ulnar nerve compression
What happens when ulnar n. Is severed?
. Clawing of digits 4-5, inability to ab/adduct digits and wasting of intrinsic palm muscles
Ulnar artery
. Accompanies ulnar nerve through ulnar canal then curves lat. to form superficial palmar arterial arch
Ulnar a. Deep branch
Accompanies the deep branch of ulnar n. And unites w/ radial artery to complete the deep palmar arterial arch
Radial a. Superficial branch
Penetrates thenar muscle mass and anastomoses w/ altar. A. To complete superficial palmar arterial arch
Radial artery pathway
. Winds dorsally across floor of anatomical snuffbox
. Passes btw heads of 1st dorsal interosseous m. To reach central compartment
. Gives large branches (princeps pollicis and radialis indicis aa.) to the 1st 2 digits
. Curves medially deep to adductor pollicis m. (Oblique head) to form deep palmar arterial arch
Superficial palmar arterial arch
. Formed primarily by ulnar a. And completed by superficial palmar branch of radial a.
. Lies deep to palmar aponeurosis but superficial to extrinsic flexor tendons
. Groves rise to common palmar digital arteries
Palmar digital aa. Pass distally and divide into ___
Proper palmar digital aa.
Deep palmar arterial arch
. Formed primarily by radial a. And completed by deep palmar branch of ulnar a.
. Prox. To superficial arch and distal to metacarpal bases
. Ant. To metacarpal shafts and interosseous mm. But post. (Deep) to adductor pollicis m.
. Gives rise to palmar metacarpal aa.
Palmar metacarpal aa.
. Pass distally in intermetacarpal spaces
. Terminate by anastomosing w/ common palmar digital aa.
How to control bleeding in surgical field of palm
. Temporarily ligate brachial a.