Download Hand - Maryville University

Hand
Bony, soft landmarks
• 1. dorsum:
– a. knuckles = metacarpal bone heads
– b. skin - thinner than palm, has hair follicles,
sebaceous & sweat glands
– c. dorsal venous network
Bony, soft landmarks
• palm:
– a. skin - much thicker than dorsum, many sweat
glands, no hair follicles or sebaceous
– b. transverse flexion creases: when
metacarpophalangeal joints flex - proximal, distal
– c. longitudinal flexion creases - when thumb is
opposed - radial & midpalmar
– d. thenar eminence - ball / heel of thumb
– e. hypothenar eminence - heel of hand at little finger
Trisomy 21
Fingers
• Also have digital transverse flexion creases proximal, middle, distal (thumb has only 2)
• Fingerprints - improve gripping ability
• Synovial sheaths
– a. radial bursa - encloses tendon of flexor pollicis
longus
– b. ulnar bursa - encloses four tendons each of flexors
digitorum superficialis & profundus
& medially, extends distally to surround the two flexor
tendons to pinkie
– c. Three separate distal sheaths - surround flexor
tendons to index, middle, ring fingers
- from metacarpophalangeal joints to base of distal
phalanx
Fingers
• Fibrous digital sheaths - dense fibrous
connective tissue
– annular bands - surround phalanges
– cruciform bands - cross over between joints
– form osteofibrous canals - through which
flexor tendons travel (in their synovial
sheaths)
• Flexor retinaculum
– Fibrous connective fascia that covers and
holds most of the flexors of the forearm in
wrist.
Carpal Tunnel Syndrome
• Because the median is enclosed with the
tendons in this tunnel, anything that decrease
the size of the tunnel (infection, arthritis,
degeneration etc.) will compress the median
nerve causing carpal tunnel syndrome. Its
symptom includes tingling sensation
(paresthenia), absence of tactile sensation
(anethesia), or diminished sensation
(hypothenia), loss strength of thumb (abductor
pollicis brevis, flexor pollicis brevis and
opponents pollicis), lumbricals (lateral two) can
also be affected.
Blood vessels
• Ulnar artery
– a. deep branch - joins radial to form deep palmar arch
– b. superficial palmar arterial arch, formed by
superficial palmar branch from ulnar artery (more like
the terminal branch of ulnar, which mainly forms the
arch) + superficial palmar branch of radial artery. It
gives off three branches and joint with palmar
metacarpal branches from deep palmar arch to form:
• i) three common palmar digital artery - in the three medial
intermetacarpal spaces; each then divides
• proper palmar digital artery - to medial side of index finger,
radial side of little finger
and both sides of middle & ring fingers
• proper palmar digital artery - little finger, ulnar side, a branch
directly from the superficial palmar arch (or a branch off the
ulnar artery)
Blood vessels
• radial a. - (sits in floor of anatomical snuff
box)
– a. superficial palmar branch - to thenar
muscles, joins superficial palmar arch (ulnar)
– b. princeps pollicis - to thumb, then splits into
two proper digital arteries to both sides of the
thumb
– c. radialis indicis - to lateral index finger
– d. deep palmar arterial arch - formed by Radial
artery (mainly). + deep branch of the ulnar a.
- three palmar metacarpal arteries - between
metacarpals - join common palmar digitals
Deep palmar arterial arch
• three palmar metacarpal arteries
• three perforating arteries to dorsal arch
Dorsal arterial arch
• a. formed by dorsal carpal branch from radial and
ulnar arteries, and terminal branches of the
anterior and posterior interosseus arteries. It is
also joined by the perorating arteries from deep
palmar arch.
• b. Dorsal arch gives off three dorsal metacarpal
arteries, each then splits into dorsal proper digital
arteries
• c. Dorsalis pollicis and dorsalis indicis can be
considered as direct branches from radial dorsal
carpal artery
• d. dorsal proper digital artery - to the medial side
of little finger, direct branch from the dorsal arch
(or branch from the dorsal carpal branch from
ulnar artery).
Nerves
• 1. ulnar nerve - superficial branch of the
ulnar nerve - enters palm on ulnar side of
center; divides:
- three palmar digital branches - to skin of
little finger (both sides), medial side ring
finger
• 2. ulnar nerve - deep branch - to muscles
of fine movements of hand
- hypothenar muscles, interosseous,
medial lumbricals, adductor pollicis
Median nerve
• Enters palm to radial side of center; divides to 3
common palmar digital branches:
– a. 1st common to abductor pollicis brevis, flexor
pollicis brevis, opponens pollicis, and 1st lumbrical
muscle
• then it divides: - 3 proper palmar digital nerve - to skin, both
sides of thumb; & lateral side of index
– b. 2nd common - to 2nd lumbrical muscle
• divides - to 2 proper palmar digital nerve - to skin of medial
index, lateral middle finger
– c. 3rd common palmar digital branch divides to 2
proper palmar digital nerve. - to skin on medial
middle, lateral ring finger
Radial nerve
• all sensory innervation in hand (dorsal &
lateral skin & fascia)
Muscles
• Thenar / short thumb muscles
ABDUCTOR POLLICIS BREVIS
• ORIGIN
Flexor retinaculum, tubercle of trapezium bone,
and tubercle of scaphoid bone
• INSERTION
Base of proximal phalanx of thumb, radial side,
and extensor expansion
• ACTION
Abducts the carpometacarpal and
metacarpophalangeal joints of the thumb in a
vertical direction perpendicular to the place of
the palm. By virtue of its attachment into the
dorsal extensor expansion, extends the
interphalangeal joint of the thumb. Assists in
opposition, and may assist in flexion and medial
rotation of the metacarpophalangeal joint.
• NERVE
median nerve - C6, C7, C8, T1
FLEXOR POLLICIS BREVIS
• ORIGIN
– Superficial head: flexor retinaculum and
trapezium bone
– Deep head: trapezoid and capitate bones
• INSERTION
Base of proximal phalanx of thumb, radial
side, and extensor expansion
• ACTION
Flexes the metacarpophalangeal and
carpometacarpal joints of the thumb, and
assists in opposition of the thumb toward
the little finger. By virtue of its attachment
into the dorsal extensor expansion, may
extend the interphalangeal joint
• NERVE
– superficial head: median nerve. - C6, C7, C8,
T1
– deep head: C8, T1
OPPONEN POLLICIS
• ORIGIN
Flexor retinaculum and tubercle of trapezium
bone
• INSERTION
Entire length of first metacarpal bone, radial
side
• ACTION
Opposes (i.e., flexes and abducts with slight
medial rotation) the carpometacarpal joint of
the thumb, placing the thumb in a position so
that, by flexion of the metacarpophalangeal
joint, it can oppose the fingers. For true
opposition of the thumb and little finger, the
pads of these digits come in contact. Bringing
the tips of these digits together can be donw
without opponens action
• NERVE
median nerve - C6, C7, C8, T1
ADDUCTOR POLLICIS
• ORIGIN
– oblique head: capitate bone, and bases of
second and third metacarpal bones
– transverse head: palmar surface of third
metacarpal bone
• INSERTION
Transverse head into ulnar side of base of
proximal phalanx of thumb, and oblique head
into extensor expansion
• ACTION
Adducts the carpometacarpal joint, and
adducts and assists in flexion of the
metacarpophalangeal joint, so that the thumb
moves toward the plane of the palm. Aids in
opposition of the thumb toward the little finger.
By virtue of the attachment of the obilique
fibers into the extensor expansion, may assist
in extending the interphalangeal joint.
• NERVE
ulnar never - C8, T1
Muscles
• Hypothenar / short muscles of little finger
ABDUCTOR DIGITI MINIMI
• ORIGIN
Tendon of flexor carpi ulnaris and pisiform
bone
• INSERTION
By two slips: one into base of proximal
phalanx of little finger, ulnar side; the
second, into the ulnar border of the
extensor expansion
• ACTION
Abducts, assists in opposition, and may
assist in flexion of the
metacarpophalangeal joint of the little
finger; by virtue of insertion into the
extensor expansion, may assist in
extension of interphalangeal joints
• NERVE
ulnar nerve - C(7), C8, T1
FLEXOR DIGITI MINIMI BREVIS
• ORIGIN
hook of hamate bone, and flexor
retinaculum
• INSERTION
base of proximal phalanx of little
finger, ulnar side
• ACTION
Flexes the metacarpophalangeal
joint of the little finger and assists in
opposition of the little finger toward
the thumb
• NERVE
ulnar never, C(7), C8, T1
OPPONEN DIGITI MINIMI HAND
• ORIGIN
hook of hamate bone, and flexor
retinaculum
• INSERTION
entire length of fifth metacarpal, ulnar
side
• ACTION
opposes (i.e., flexes with slight rotation)
the carpometacarpal joint of the little
finger, lifting the ulnar border of the
hand into a position so that the
metacarpophalangeal flexors can
oppose the little finger to the thumb.
Helps to cup the palm of the hand
• NERVE
ulnar nerve - C(7), C8, T1
Muscles
• Short Hand muscles
LUMBRICALS
• ORIGIN
– #1 and #2: radial surface of flexor
profundus tendons of index and
middle fingers, respectively.
– #3: adjacent sides of tendon of
flexor digitorum profundus tendons
of middle and ring fingers
– #4: adjacent sides of tendon of
flexor digitorum profundus of ring
and little fingers
• INSERTION
Into the radial border of the
extensor expansion on the
dorsum of the respective digits
LUMBRICALS
• ACTION
Extend the interphalangeal joints and
simutaneously flex the metacarpophalangeal
joints of the second through fifth digits. The
lumbricales also extend the interphalangeal
joints when the metacarpophalangeal joints are
extended. As the fingers are extended at all
joints, the flexor digitorum profundus tendons
offer a form of passive resistance to this
movement. Since the lumbricales are attached
to the flexor profundus tendons, they can
diminish this resistive tension by contracting
and pulling these tendons distally, and this
release of tension decreases the contractile
force needed by the muscles that extend the
finger joints.
• NERVE
I, II: median nerve, C(6), 7, C8, T1 III, IV: ulnar
nerve – C(7), C8, T1
DORSAL INTEROSSEI
•
ORIGIN
– First, lateral head: Proximal one half of ulnar border of
first metacarpal bone
– First, medial head: radial border of second metacarpal
bone
– second, third, and fourth: adjacent sides of metacarpal
bones in each interspace
•
INSERTION
into extensor expansions and to base of proximal
phalanges as follows:
– First: radial side of index finger, chiefly to base of
proxiaml phalanx
– Second: radial side of middle finger
– Third: ulnar side of middle finger, chiefly into extensor
expansion
– Fourth: ulnar side of ring finger
•
•
ACTION
Abducts the index, middle, and ring fingers from the
axial line through the third digit. Assists in flexion of
metacarpophalangeal joints and extension of
interphalangeal joints of the same fingers. The first
assists in addition of the thumb
NERVE
ulnar nerve - C8, T1
PALMAR INTEROSSEI
• ORIGIN
– First: base of first metacarpal bone, ulnar side
– Second: length of second metacarpal bone, ulnar
side
– Third: length of fourth metacarpal bone, radial side
– Fourth: length of fifth metacarpal bone, radial side
• INSERTION
Chiefly, into the extensor expansion of the
respective digit, with possible attachement to base
of proximal phalanx as follows
–
–
–
–
First: ulnar side of thumb
Second: ulnar side of index finger
Third: radial side of ring finger
Fourth: radial side of little finger
• ACTION
Adduction of thumb, index , ring, and little finger
toward the axial line through the third digit. Assist in
flexion of metacarpophalangeal joints, and
extension of interphalangeal joints of the three
fingers
• NERVE
ulnar nerev C8, T1