PALM

Dr.Deepak N.Khedekar.Dept .of AnatomyLTMMC &GH.2015

Introduction

Human hand Specifically palm region is designed for …

• Grasping• Precise movements• Tactile organ

Palm

• Skin• Superficial fascia• Deep fascia• Muscles• Blood supply• Nerve supply

Skin

• Thick• Immobile• Creased• Abundant of sweat glands• Supply C 6,7,8 dermatomes

Superficial fascia

• Dense fibrous tissue• Divide subcut. Fat in small tight compartments• Acts as water cushion • Contain subcutaneous muscle Palmaris brevis• Superficial metacarpal ligaments stretches

across the roots of the fingers over digital vessels and nerves

Deep fascia

• Flexor retinaculum• Palmar aponeurosis• Fibrous flexor sheaths

Flexor retinaculum

• Strong fibrous band• Bridges carpal tunnelAttachments:• Pisiform• Hook of Hammate• Scaphoid tubercle• Crest of Trapezium

Carpal tunnel

Carpal tunnel

Structures passing above it• Palmar cut.br.median N.• Palmaris longus• Palmar cut.br.ulnar N.• Ulnar V.• Ulnar N.

Flexor retinaculum

Structures passing below it• Median nerve• Flx.dig.sup.• Flx.dig.profundus• Flx.poliicis longus• Ulnar bursa• Radial bursa• Flx.carpi radialis (in trapezium groove)

Palmar aponeurosis

• Central part of the deep fascia• Triangular in shape• Covers superficial palmar arch, long flexors

tendons, median nerve, ulnar nerve(sup.br)• Divides into superficial & deep layer• Deep layer divides into 2 parts continuous

with fibrous flexor sheath.

Palmar aponeurosis

• Extends up to capsule metacarpophalangeal joint, base of proximal phalanx

• FunctionsFixes the skinImproves the gripProtect underlying tendon, vessels & nerves.

Fibrous flexor sheath

• Made up of deep fascia, Thick & Arched• Attached to sides of the phalanges &across

the distal phalanx , Proximally continuous to palmar aponeurosis

• Exist as…– annular bands - surround phalanges – cruciform bands - cross over between joints– form osteofibrous canals - through which flexor

tendons travel (in their synovial sheaths)

fibrous flexor sheath

digital synovial sheath

Synovial sheaths

• Radial bursa - encloses tendon of flexor pollicis longus

• Ulnar bursa - encloses four tendons each of flexors digitorum superficialis & profundus& medially, extends distally to surround the two flexor tendons

• Three separate distal digital synovial sheaths - surround flexor tendons to index, middle, ring fingers extends from metacarpophalangeal joints to base of distal phalanx .

Intrinsic Muscles

• 20 muscles for gripping skilled, movements• 3 thenar • Adductor pollicis• 4 hypothenar• 4 lumbricals• 4 palmar interossei• 4 dorsal interossei

Thenar muscles

• Abductor pollicis brevis• Flexor pollicis brevis• Opponens pollicis• Adductor pollicis

ABDUCTOR POLLICIS BREVIS • ORIGIN

Flexor retinaculum, tubercle of trapezium bone, and tubercle of scaphoid bone

• INSERTIONBase of proximal phalanx of thumb, radial side

• ACTIONAbducts 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.

• NERVEmedian 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• 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: median nerve C8, T1

OPPONENS POLLICIS • ORIGIN

Flexor retinaculum and tubercle of trapezium bone

• INSERTIONEntire length of first metacarpal bone shaft, radial side on palmar aspect.

• ACTIONOpposes (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.

• NERVEmedian 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 shaft

• INSERTIONTransverse head into ulnar side of base of proximal phalanx of thumb, and oblique head into extensor expansion

• ACTIONAdducts 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 oblique fibers into the extensor expansion, may assist in extending the interphalangeal joint.

• NERVEulnar never - C8, T1

Hypothenar muscles

• Palmaris brevis• Abductor digiti minimi• Flexor digiti minimi• Opponens digiti minimi

ABDUCTOR DIGITI MINIMI • ORIGIN

Tendon of flexor carpi ulnaris and pisiform bone

• INSERTIONBy two slips: one into base of proximal phalanx of little finger, ulnar side; the second, into the ulnar border of the extensor expansion

• ACTIONAbducts, 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

• NERVEulnar nerve - C(7), C8, T1

FLEXOR DIGITI MINIMI BREVIS

• ORIGINHook of hamate bone, and flexor retinaculum

• INSERTIONBase of proximal phalanx of little finger, ulnar side

• ACTIONFlexes the metacarpophalangeal joint of the little finger and assists in opposition of the little finger toward the thumb

• NERVEulnar never, C(7), C8, T1

OPPONEN DIGITI MINIMI HAND • ORIGIN

hook of hamate bone, and flexor retinaculum

• INSERTIONentire length of fifth metacarpal, ulnar side

• ACTIONopposes (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

• NERVEulnar nerve - C(7), C8, T1

Dorsal Digital Expansion

Dorsal digital expansion

Lumbricals• Arise from 4 tendons of flexor

digitorum profundus• ACTION• Extend the interphalangeal joints • flex the metacarpophalangeal• 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.

• • NERVE

I, II: median nerve, C(6), 7, C8, T1 III, IV: ulnar nerve – C(7), C8, T1

Lumbricals

Palmar Interossei

• Unipennate in origin• 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

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

• INSERTIONChiefly, into the extensor expansion of the respective digit, with possible attachment 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

• NERVEulnar nerve C8, T1

Palmar interossei.

Dorsal interossei• Bipennate in origin• 1st and 5th no dorsal interossie• 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

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

• INSERTIONinto extensor expansions and to base of proximal phalanges as follows:– First: radial side of index finger, chiefly to base of proximal phalanx– Second: radial side of middle finger– Third: ulnar side of middle finger, chiefly into extensor expansion– Fourth: ulnar side of ring finger

• NERVEulnar nerve - C8, T1

Dorsal interossei

Blood supply

• Radial artery• Ulnar artery

• Superficial palmar arch• Deep palmar arch

Superficial palmar arch• Represent important anastomosis between ulnar and radial

artery formed by direct • continuation of ulnar artery beyond flexor retinaculum.• Lateral side the arch is completed by sup.palm.br.of radial side • Lies deep to palmaris brevis and palmar aponeurosis• Branches:• 3 common digital branches for 3 ½ fingers• Proper digital br.• Supplying medial 31/2 fingers•

Deep palmar arch

• Situated to deep to long flexors, lumbricals, adductor pollicis muscles lies at prox. parts of shafts of metacarpals with interossei.

• Mainly formed by the radial artery• Completed by at base 5th MC bone with deep br.of ulnar

artery Branches-• 3 Palmar metacarpal arteries• Perforating digital arteries dorsally• Recurrent br.

Blood supply of the Palm

Nerve supply

• Ulnar nerve• Median nerve

Ulnar nerve• superficial branch is cutaneous - enters palm on

ulnar side of center; divides: three palmar digital branches - to skin of little finger (both sides), medial side ring finger

• deep branch - to muscles of fine movements of hand i.e.

• Hypothenar muscles,• Interossei• Medial 2 lumbricals, • Adductor pollicis ,deep head flx.pollicis brevis• Articular branch to wrist joint

Median nerve• Controls the movement of the thumb and in gripping• Lies deep to the retinaculum in front of ulnar bursa• Divides into medial and lateral divisions• lateral division gives muscular branch to thenar

muscles,2 digital branches to lateral 1 ½ fingers• Medial division gives branches to 2nd and 3rd

interdigital cleft.

Median nerve• 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

NERVE SUPPLY

Spaces of the hand

Palmar spaces:• Pulp space of finger• Midpalmar space• Thenar space

Applied anatomy

Carpal Tunnel Syndrome• 1.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.

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