This document provides an overview of the anatomy of the palm. It describes the palmar skin as thick, glabrous, and rich in sweat glands. It is firmly attached to the underlying palmar aponeurosis by fibrous bands. The document outlines the creases and lines of the palmar skin, as well as the layers of fascia in the palm including the palmar aponeurosis and flexor retinaculum. It also describes the muscles of the palm including the thenar, hypothenar, interossei and lumbrical muscles. Additionally, it discusses the arteries, nerves and fascial spaces of the palm.

1. PALM
DR. SUNDIP CHARMODE
ASSOCIATE PROFESSOR
DEPARTMENT OF ANATOMY
AIIMS RAJKOT

2. INTRODUCTION
• Skin: thick, glabrous, devoid of sebaceous glands and rich in sweat
glands.
• Palmar skin is immobile, firmly attached to underlying palmar
aponeurosis by fibrous bands.
• Entangled subcutaneous fat in loculi under pressure.

3. CREASES/LINES OF PALMAR SKIN
• Flexure lines: form visible markings close to the synovial joints,
where the skin is tightly adherent to the deep fascia.
• Papillary ridges/fingerprints: Corresponds to the pattern of
underlying dermal papillae which varies from person to person and in
different digits of the same person.
• Langer lines: Cleavage lines are produced by the bundles of collagen
fibers of the dermis.

4. PALMAR SKIN
• Superficial fascia: The subcutaneous tissue contains fat in small tight
compartments.
• Deep fascia: Thickened to form three specialized parts:
1. Flexor retinaculum
2. Palmar aponeurosis
3. Fibrous flexor sheaths of the digits

5. SUPERFICIAL TRANSVERSE METACARPAL
LIGAMENT
• Superficial transverse metacarpal ligament (Natatory ligament):
• The fibres of the superficial transverse metacarpal ligament cross the
apex of the web skin and extend into each digit to blend with the
lateral digital sheet.
• They limit the separation of adjacent fingers and form the distal
commissural ligament in the web space of the thumb.

7. TRANSVERSE FIBRES OF THE PALMAR
APONEUROSIS
• The transverse fibres of the palmar aponeurosis represent the deepest
layer of the palmar fascia.
• They lie proximal to the distal palmar crease in a band approximately
2 cm wide, interconnecting the anterior fibres of the flexor tendon
sheaths with the fasciae over the thenar and hypothenar muscles.
• The extension to the first ray forms the proximal commissural
ligament.

8. DEEP TRANSVERSE METACARPAL
LIGAMENT
• The strong fibres of the deep transverse
metacarpal ligament lie deep to the
palmar aponeurosis and flexor sheaths
and are attached to the palmar plates of
the metacarpal heads of the fingers.

9. FLEXOR RETINACULUM
• Strong fibrous band which acts as a tie-beam and converts the anterior
concave surface of carpus into an Osseo-fibrous Carpal Tunnel.

11. ATTACHMENTS

12. ATTACHMENTS
• Medially: Pisiform bone and Hook of hamate
• Laterally: Tubercle of scaphoid and crest of trapezium
• On each side: gives slips of attachment
• Proximally: Blends with antebrachial fascia in superficial plane and
with the fascia covering flexor digitorum superficialis in deeper plane.
• Distally: Continuous with palmar aponeurosis and palmar fascia.

14. RELATIONS
• Structures passing superficial to
flexor retinaculum:
1. Palmaris longus tendon
2. Palmar cutaneous branch of
median nerve
3. Palmar cutaneous branch of ulnar
nerve
4. Superficial palmar branch of
radial artery
5. Ulnar nerve and vessels
• Structures passing deep to flexor
retinaculum:
1. Median nerve
2. Tendons of flexor digitorum
superficialis
3. Tendons of flexor digitorum
profundus
4. Tendon of flexor pollicis longus
5. Flexor carpi radialis tendon

17. PALMAR APONEUROSIS
• It is the deep fascia of the palm and
consists of central, medial and lateral
parts.
• Central part: thick, forms palmar
aponeurosis proper
• Medial part: thin, hypothenar muscles.
• Lateral part: thin, thenar muscles.
• Becomes continuous with deep fascia on
dorsum of hand.

18. CENTRAL PART OF
PALMAR APONEUROSIS
• Triangular
• Proximally:
• Distally: fans out as a thick sheet and at the
bases of the fingers splits into four digital
slips for the medial four fingers.
• Each slip divides into superficial and deep
sets of fibers.
• Superficial fibers join with dermis and blend
with superficial transverse ligament of palm.

19. CENTRAL PART OF PALMAR APONEUROSIS
• Deep set of fibers of each slip divides
into two bands which are attached to the:
• Deep transverse ligament of palm
• Palmar ligaments of metacarpo-
phalangeal joints
• Bases of proximal phalanges and
• Blends with the fibrous flexor sheaths.
• Medial and Lateral palmar septa:
Extend dorsally from the respective
margins of the central part of aponeurosis.
These septa divide the palm into fascial
lined spaces.

20. FUNCTIONS OF PALMAR APONEUROSIS
1. Provides firm attachment to the overlying skin to improve the grip
2. Protects palmar vessels and nerves and prevents the flexor tendons
from bow stringing.
3. Provides origin to Palmaris brevis from its apex for stronger grip on
the ulnar side.
4. Palmar septa divide the palm into fascial lined potential spaces of
surgical importance.
5. Palmar aponeurosis presents 4 digital slips to medial four digits and
that allows free movement of the thumb.

21. DUPUYTREN’S CONTRACTURE
• Inflammation of palmar
aponeurosis produces thickening
and its contracture.
• Proximal and middle phalanges
are acutely flexed because
palmar fascia is attached to it.
• Terminal phalanges remain
unaffected.

22. FIBROUS FLEXOR SHEATHS
• To retain the flexor tendons in position, all five digits are provided
with a strong unyielding fibrous sheath extending from the metacarpal
head to base of distal phalanx.
• Fibrous sheath of thumb contains the tendon of flexor pollicis longus.
• In medial four fingers, the sheaths are occupied by flexor profundus
and flexor superficialis.
• Each sheath crosses three joints: MC-Phalangeal, proximal and distal
interphalangeal joints.
• The sheaths present a series of thick zones over the phalanges and thin
zones over the joints.

25. DIGITAL SYNOVIAL SHEATHS
• To avoid friction of flexor tendons against the Osseo-fibrous canals of
digits, each tendon is enveloped by a tubular synovial sheath.
• Closed at both ends.
• Consists of parietal and visceral layer
• Parietal layer – lines the walls of Osseo-fibrous canal
• Visceral layer – covers the flexor tendons.
• Vincula (remnants of mesotendon): Brevia and Longa
• Each finger presents two Vincula Brevia and three Vincula Longa
• Vincula Brevia: triangular folds
• Vincula Longa: filiform folds

27. DIGITAL SYNOVIAL
SHEATHS
• Digital synovial sheath of little finger is
continuous proximally with ulnar bursa.
• Digital synovial sheath of thumb is
continuous proximally with radial bursa.
• Synovial sheaths of index, middle and index
fingers are independent and extend
proximally up to the level of metacarpal
heads.

28. GUYON’S CANAL
• Fibro-osseous canal, approximately 4 cm long in
the adult, on the anteromedial side of the wrist.
• Roof: Palmar carpal ligament and palmaris brevis.
• Floor: Transverse carpal and Piso-hamate
ligaments and, more distally, by the Piso-
metacarpal ligaments and flexor digiti minimi.
• Ulnar side: Flexor carpi ulnaris, the pisiform bone
and abductor digiti minimi.
• Medial side: Extrinsic flexor tendons, the
transverse carpal ligament and the hook of the
hamate.
• Transmits ulnar nerve and artery, together with
occasional venae comitantes.

29. INTRINSIC MUSCLES OF HAND
• The intrinsic muscles of the hand
are organized into three groups
plus a superficial muscle.
• The Thenar muscles include
1. Flexor pollicis brevis
2. Abductor pollicis brevis
3. Opponens pollicis and
4. Adductor pollicis.
• The Hypothenar muscles
include
1. Abductor digiti minimi
2. Flexor digiti minimi brevis
3. Opponens digiti minimi.
• The interossei and lumbricals act
on the fingers.
• Palmaris brevis is a superficial
muscle that lies beneath the ulnar
palmar skin.

30. THENAR MUSCLES
SR.
no
Name of the
muscle
Origin Insertion Nerve
Supply
Action
1 Flexor pollicis
brevis
The superficial head - distal border
of the flexor retinaculum and the
distal part of the tubercle of the
trapezium
The deep head - trapezoid and
capitate bones and from the palmar
ligaments of the distal row of
carpal bone.
Radial side of the base of
the first phalanx.
Recurrent
branch of
median
nerve
Flexes the
metacarpophalangeal
joint.
2 Abductor
pollicis brevis
• Flexor retinaculum,
• few fibres from the tubercles of
the scaphoid and trapezium
• Tendon of abductor pollicis
longus.
Medial fibres attach to
the radial side of the base
of the proximal phalanx
of the thumb,
Lateral fibres join the
dorsal digital expansion
of the Extensor Pollicis
longus.
Recurrent
branch of
median
nerve
Abducts the thumb at
right angles to the
plane of the palm.
Rotates the thumb
medially.

32. THENAR MUSCLES
SR.
no
Name of the
muscle
Origin Insertion Nerve Supply Action
3 Opponens pollicis Flexor retinaculum
Crest of trapezium
Whole length of the lateral
border, and the adjoining
lateral half of the palmar
surface of the metacarpal bone
of the thumb.
Recurrent
branch of
median nerve
Flexes and medially
rotates the
metacarpal bone of
the thumb.
Opposition of thumb
4 Adductor pollicis Transverse head:
Longitudinal ridge on the
palmar surface of third
metacarpal bone.
Oblique head: Bases of the
second and third
metacarpals and the
adjoining trapezium and
capitate
Ulnar side of the base of
proximal phalanx of the thumb
Deep branch of
ulnar nerve
Approximates the
thumb to the index
finger from any
position of the thumb

33. HYPOTHENAR MUSCLES
SR.
no
Name of the
muscle
Origin Insertion Nerve Supply Action
1 Abductor digiti
minimi
• Pisiform bone
• Tendon of flexor carpi
ulnaris
• Piso-hamate ligament
One slip to ulnar side of base
of proximal phalanx of little
finger.
Other slip joins ulnar border
of dorsal digital expansion of
little finger
Deep branch of
ulnar nerve
Deepening the cup of
palm for proper grip
on a large object.
2 Flexor digiti
minimi
• Flexor retinaculum
• Hook of hamate
Ulnar side of the base of
proximal phalanx of the little
finger (along with Abductor
digiti minimi)
Deep branch of
ulnar nerve
Deepening the cup of
palm for proper grip
on a large object.

35. HYPOTHENAR MUSCLES
SR.
no
Name of the
muscle
Origin Insertion Nerve Supply Action
3 Opponens digiti
minimi
Flexor retinaculum
Hook of hamate
Ulnar side of the palmar
surface of shaft of fifth
metacarpal bone
Deep branch of
ulnar nerve
Deepening the cup of
palm for proper grip
on a large object.
4 Palmaris brevis Subcutaneous striated
muscle.
Arises from
• Flexor retinaculum
• Palmar aponeurosis
Dermis of the ulnar border of
the palm
Superficial
branch of ulnar
nerve
Protects the
underlying ulnar
vessels and nerve.
May improve the
palmar grip.

36. LUMBRICAL MUSCLES
Name of the
muscle
Origin Insertion Nerve Supply Action
First and second
lumbricals
Arise from the radial side of
flexor digitorum profundus
tendon for index and middle
fingers.
Radial side of the dorsal
digital expansion of the
medial four fingers.
Through the dorsal digital
expansion, the lumbricals
are inserted into the
dorsal surfaces of the
bases of middle and distal
phalanges.
Median nerve from
superficial surface
Acts a link
muscles since they
connect the deep
flexor tendons to
the extensor
tendons of the
fingers via dorsal
digital expansion.
Third and fourth
lumbricals
Arise from the adjacent sides
of flexor digitorum profundus
tendon for middle, ring and
little fingers.
Deep branch of
ulnar nerve from
deep surface

37. LUMBRICAL
MUSCLES
• First and second lumbricals –
unipennate
• Third and fourth lumbricals -
bipennate

38. PALMAR INTEROSSEI MUSCLES
SR.
no
Name of the
muscle
Origin Insertion Nerve
Supply
Action
1 First palmar
interossei
Ulnar side of the base of
first metacarpal
Partly to the base of proximal
phalanx of the corresponding
digit on the side of their
origins.
Partly to the dorsal digital
expansion.
Deep
branch of
ulnar nerve
• Adductors of the
fingers
• Flexors of metacarpo-
phalangeal joints
• Extensors of inter-
phalangeal joints
2 Second palmar
interossei
Ulnar side of the shaft of
second metacarpal
3 Third palmar
interossei
Radial side of the shaft of
fourth metacarpal
4 Fourth palmar
interossei
Radial side of the shaft of
fifth metacarpal

39. PALMAR INTEROSSEI
MUSCLES
• Unipennate

40. DORSAL INTEROSSEI MUSCLES
SR.
no
Name of the
muscle
Origin Insertion Nerve Supply Action
1 First dorsal
interossei
Palmar surfaces of shafts
of first and second
metacarpal
Partly to the radial side of
bases of proximal phalanges
of the index finger and middle
finger respectively.
Partly to the dorsal digital
expansion of the
corresponding digits. Deep branch of
ulnar nerve
• Abductors of the
fingers
• Flexors of
metacarpo-
phalangeal joints
• Extensors of
inter-phalangeal
joints
2 Second dorsal
interossei
Palmar surfaces of shafts
of second and third
metacarpal
3 Third dorsal
interossei
Palmar surfaces of shafts
of third and fourth
metacarpal
Partly to the ulnar side of
bases of proximal phalanges
of the middle and ring finger
respectively.
Partly to the dorsal digital
expansion of the
corresponding digits.
4 Fourth dorsal
interossei
Palmar surfaces of shafts
of fourth and fifth
metacarpal

41. DORSAL INTEROSSEI
MUSCLES
• Bipennate

42. PALM -II
DR. SUNDIP CHARMODE
ASSOCIATE PROFESSOR
DEPARTMENT OF ANATOMY
AIIMS RAJKOT

43. CONTENTS
1. Arteries of palm
2. Nerves of palm
3. Fascial spaces of palm

44. ARTERIES OF PALM
• Radial artery
• Ulnar artery

45. ARTERIALARCHES OF PALM
• Superficial Palmar Arch
• Deep Palmar Arch

46. SUPERFICIAL PALMAR ARCH
• Formation: Superficial terminal branch of ulnar artery (medially) and is
completed on lateral side by one of the following branches:
1. Superficial palmar branch of radial artery
2. Arteria princeps pollicis
3. Arteria radialis indicis
4. Arteria nervi mediana which accompanies median nerve
• Position/Location: Arterial arcade which lies beneath the palmar
aponeurosis and in front of the long flexor tendons, lumbricals and palmar
digital branches of median nerve.
• Distribution: Does not supply the radial side of index finger and both sides
of the thumb.

47. SUPERFICIAL PALMAR ARCH
• Branches:
1. Four palmar digital
arteries
2. Common palmar digital
arteries
3. Two proper palmar
digital arteries

48. DEEP PALMAR ARCH
• Formation: it is an arterial arcade formed by anastomosis between the
terminal end of radial artery and the deep branch of ulnar artery.
• Position /Location: Lies deep to the oblique head of adductor pollicis,
long flexor tendons and lumbricals and passes across the bases of
metacarpals and interossei.

49. DEEP PALMAR ARCH
• Branches:
1. Three palmar metacarpal arteries
2. Three perforating arteries
3. Recurrent branches

51. NERVES OF PALM
Median nerve
• Five muscles: Three thenar and
two (1st and 2nd ) lumbricals.
• Skin of the lateral three and one
half of the digits, including the
joints of the digits and local blood
vessels.
Ulnar nerve
• Fifteen Muscles :
• Three hypothenar muscles
• Adductor pollicis
• Palmaris brevis
• 3rd and 4th lumbricals
• All palmar and dorsal interossei
• Articular branches :Intercarpal and
carpo-metacarpal joints
• Vascular branches: deep palmar
arch and its branches.
• Skin of the medial one and half of
the digits, including ulnar side of
hand.

52. MEDIAN NERVE IN
PALM
• Two branches – lateral and medial branches
• Recurrent branch –
• Lateral branch – Three proper palmar digital
nerves
• Medial branch- Two common palmar digital
nerves (lateral and medial)
• Medial common digital nerve – receives
communicating branch from ulnar nerve

53. ULNAR NERVE IN PALM
• Two branches – Superficial and Deep terminal
branches
• Superficial terminal branch- Muscular twig to
palmaris brevis, and
• Two branches – (one) proper palmar digital
nerve and one common palmar digital nerve.
• The digital nerves in addition to palmar skin
also supplies:
• Metacarpo-phalangeal joints
• Inter-phalangeal joints
• Local blood vessels
• Pulp spaces , nail beds and
• Skin of dorsal surface over middle and terminal
phalanges of medial one and half of digits.

56. PALMAR SPACES

57. FASCIAL SPACES OF PALM
• Three fascial lined potential spaces limited by fibrous septa in the palm
and the palmar aspect of terminal phalanges warrant surgical
importance.
• Central hollow of palm is occupied by :
1. Palmar aponeurosis
2. Long flexor tendons (covered by synovial sheaths)
3. Lumbricals
• Deep to these structures is a large fascial lined Central Palmar Space.

58. FASCIAL SPACES OF PALM
• Central Palmar Space is bounded on sides by :
1. Medial palmar septa
2. Lateral palmar septa
• Central Palmar Space is divided by an Intermediate Fibrous Septa
into:
• Mid-Palmar Space – Ulnar side
• Thenar space – radial side

59. FASCIAL SPACES OF PALM
1. Mid-Palmar space
2. Thenar space
3. Pulp space

60. MID PALMAR SPACE
• Triangular in shape
Boundaries :
In front :
• Flexor tendons of little, ring and middle fingers
with their synovial sheaths
• Third and fourth lumbricals
Behind :
• Deep fascia covering the interossei and the
metacarpal bones of 3rd and 4th spaces

61. MID PALMAR SPACE
Laterally : Intermediate Fibrous Septum
Medially : Hypothenar muscles separated by Medial palmar septum
Proximally : Space is closed by attachment of the parietal layer of Ulnar
bursa to the floor of carpal tunnel.
Sometimes continuous with ‘Space of Parona’.

62. Mid Palmar Space -
Triangular in shape
Distally : Extends as
diverticula to the webs of
the fingers along the
fascial sheaths of 3rd and
4th Lumbrical muscles.

66. THENAR SPACE – TRIANGULAR SPACE
Boundaries :
In front :
1. Muscles of Thenar eminence
2. Flexor tendon of Index finger
3. First and second Lumbrical
muscles
Behind : Adductor Pollicis
Laterally : Tendon of Flexor
Pollicis longus

67. THENAR SPACE – TRIANGULAR SPACE
Medially : Intermediate fibrous
septum
Proximally : same as mid
palmar space
Distally :The space extends as
fascial diverticula along first and
second lumbrical tendons to the
Inter-digital clefts.

68. CLINICALASPECTS
• Proximal ends of the digital synovial sheaths of index, middle and ring
fingers extend to the distal limits of Mid-palmar and Thenar spaces.
• Therefore, pus from infected flexor sheaths may burst into and distend
the palmar spaces.

69. PULP SPACE
• These are the spaces which intervene between the palmar skin and
distal phalanges of all digits of hand.
• Lie distal to the fibrous sheaths of flexor tendons.
• In each space, the skin is connected to the periosteum of the distal
phalanx by numerous radiating fibrous septa.
• Dividing the space into numerous tight compartments containing fat
and blood vessels.

70. PULP SPACE
• Distal 4/5th of distal
phalanx – digital arteries
by penetrating dense
fibrous septa.
• Proximal 1/5th of distal
phalanx – receives
separate blood supply
through separate digital
arteries without
traversing the septa.

71. APPLIED ANATOMY
• Whitlow – Infection of pulp space, associated with severe throbbing
pain due to increased tension in the tight inter-septal space.
• Whitlow is drained by Lateral incision – opening all inter-septal
compartments without damaging the sensitive skin of pulp.
• In neglected cases, Avascular necrosis of distal 4/5th of distal phalanx
but basal 1/5th of the bone remains unaffected.

73. SPACE OF PARONA
• Fascial lined potential space deep to long flexor
tendons of forearm, where proximal parts of the
synovial sheaths of flexor tendons of hand extend.
• Boundaries:
• In front: Flexor digitorum profundus and flexor
pollicis longus
• Behind: Pronator quadratus and interosseous
membrane
• Above: oblique origin of flexor digitorum
superficialis
• On each side: limited by outer and inner borders
of forearm

74. PARONYCHIUM
When pus is formed due to formation of
paronychium or eponychium, it can be drained by
lifting the nail fold with a needle.
In infection of nail bed, the eponychium is pushed
back and the portion of nail overlying the pus is
excised.

75. APPLIED ANATOMY
1. Ulnar nerve compression / entrapment :
I. Behind Medial Epicondyle – Cubital tunnel syndrome
II. At Wrist – Carpal tunnel syndrome
2. Ulnar Paradox :
3. Card test :
4. Froment sign :

76. SIGNS OF ULNAR NERVE PALSY
• Flexion of wrist joint – abduction of wrist
• Thumb cannot be adducted - Adductor pollicis paralysis
• Wasting of hypothenar eminence
• Sensory loss over skin over palmar aspect of medial 1 ½ digits and medial half of hand.
• Medial four fingers cannot be abducted and adducted.
• Extension at Metacarpo-phalangeal joint
• Flexion at Inter-phalangeal joint – Claw hand

77. CLAW HAND

80. ULNAR NERVE ENTRAPMENT AT MEDIAL
EPICONDYLE
• Flexion of wrist joint – abduction of wrist
• Thumb cannot be adducted - Adductor pollicis
paralysis
• Wasting of hypothenar eminence
• Sensory loss over skin over palmar aspect of
medial 1 ½ digits and medial half of hand.
• Medial four fingers cannot be abducted and
adducted.
• Extension at Metacarpo-phalangeal joint
• Flexion at Inter-phalangeal joint – Claw hand
ULNAR NERVE ENTRAPMENT AT WRIST
• Adduction and abduction at wrist
joint will not be affected.
• Claw hand condition become more
evident.
• Ulnar Paradox

82. FROMENT’S SIGN

85. THANK YOU