Download PALMAR APONEUROSIS

PALMAR APONEUROSIS
MUSCLES OF HAND
MOVEMENTS OF THUMB
ANATOMICAL SNUFFBOX
OBJECTIVES
At the end of lecture student should be able to:
•
Recall the structure and functions of palmar aponeurosis
•
Recall the attatchments, nerve supply & actions of muscles of hand
•
Correlate the movements of thumb with hand anatomy
•
Identify the anatomical snuffbox
•
Relate applied with gross anatomy of few structures of hand
Deep fascia of wrist is thickened to form flexor retinaculum and palmar
aponeurosis
PALMAR APONEUROSIS
•
•
•
Also called palmar fascia
invests the muscles of the palm
consists of central, lateral, and medial portions.
The central triangular portion
 Occupies the middle of the palm
 Has great strength and thickness.
 Its apex is continuous with distal border of
flexor retinaculum and receives the
expanded tendon of the palmaris longus.
 Its base divides below into four slips, one
for each finger
 Each slip gives off superficial fibers to the
skin of the palm and finger
 The deeper part of each slip subdivides into two processes, which are
inserted into the fibrous sheaths of the flexor tendons
The lateral and medial peripheral portions of palmar aponeurosis
 Are thin& fibrous
 Cover on the radial side, the muscles of
the ball of the thumb
 Cover on the ulnar side the muscles of
the little finger
 They are continuous with the central
portion and with the fascia on the dorsum
of the hand
Functions of palmar aponeurosis




Provides firm attachment to overlying skin
Helps to form the ridges in the palm which in turn help to increase friction
so that we can grasp objects firmly.
Protects underlying structures
Provides attachment to muscles
SUPERFICIAL MUSCLE OF PALM
PALMARIS BREVIS
 Origin
Flexor retinaculum and palmar aponeurosis
 Insertion
Skin of palm into dermis
DEEP MUSCLES OF PALM
When the skin, palmar aponeurosis and flexor retinaculum are removed the
structures seen are:
 The tendons of the flexor digitorum superficialis
 Medial to the tendons is a group of muscles that act on the little finger, the
hypothenar muscles.
 Lateral to the tendons is a group of muscles that act on the thumb (pollux),
the thenar muscles.
THENAR & HYPOTHENAR MUSCLES
THENAR MUSCLES
Comprise the intrinsic musculature of the thumb
Include the
 Abductor pollicis brevis
 flexor pollicis brevis
 Opponens pollicis
 Other than thenar muscles thumb also has Adductor pollicis
ABDUCTOR POLLICIS BREVIS
 ORI.: flexor retinaculum of wrist
scaphoid & trapezium
 INS.: base of proximal phalanx of thumb
 N.S: median
 ACT: abducts the thumb at metacarpophalangeal
joint
(M.P.J)
FLEXOR POLLICIS BREVIS
 ORI.: flexor retinaculum
trapezium
 INS: base of proximal phalanx of thumb
 N.S:median
 flexes the thumb at M.P.J
OPPONENS POLLICIS
 ORI.: trapezium & flexor retinaculum
 INS: lateral border of shaft of 1st metacarpal
 N.S.: median
 ACT.: opposes thumb to other digits
MUSCLE OF THUMB
(not included in thenar group)
ADDUCTOR POLLICIS
 ORI.:obliquehead: Capitate, 2nd & 3rd metacarpals
transverse head: shaft of 3rd metacarpal
 INS: proximal phalanx of thumb
 N.S: deep branch of ulnar
 ACT: adducts the thumb
HYPOTHENAR MUSCLES
 Group of three muscles
 control the motion of the little finger.
 The three muscles are • abductor digiti minimi • flexor digiti minimi
• opponens digiti minimi...
ABDUCTOR DIGITI MINIMI
 ORI.:pisiform
 INS.: base of proximal phalanx of little finger
 N.S: deep br. of ulnar
 ACT: abducts little finger at M.P.J
FLEXOR DIGITI MINIMI
 ORI.: flexor retinaculum
hook of hamate
 INS.: base of proximal phalanx of little finger
 N.S: deep br. of ulnar
 ACT: flexes little finger at M.P.J
OPPONENS DIGITI MINIMI
 ORI.:flexor retinaculum
hook of hamate
 INS.: medial border of shaft of 5th metacarpal
 N.S: deep br. of Ulnar
 ACT: opposes little finger to other
LUMBRICALS
 I, II,III & IV
(from lateral to medial)
 ORI:tendons of flexor digitorum profundus
 INS:lateral aspect of corresponding extensor
expansion
 N.S: I, II by Median & III, IV by ulnar
 ACT: flex the M.P.J, extend the interphalangeal
joints
PALMAR INTEROSSEI(I,2,3)
1st palmar interossei
 ORI: medial side of2ndmetacarpal,
 INS: medial side of base of proximal phalanx of index
finger
nd
2 palmar interossei
 ORI: lateral side of 4th metacarpal,
 INS:lateral side of base of proximal phalanx of ring
finger
rd
3 palmar interossei
 ORI:lateral side of 5th metacarpal,
 INS:medial side of base of proximal phalanx of little
finger
DORSAL INTEROSSEI(1,2,3,4)
 ORI.:All 4 arise by two heads , one from eaqch
matacarpal bone bounding the interosseous space
 INS:1&2, lateral side of base of proximal phalanx of
index & middle fingers resp
 3&4lateral side of base of proximal phalanx of index &
middle fingers resp.( all into corresponding ext.
expansion also)
PALMAR & DORSAL INTEROSSEI
NERVE SUPPLY
 all interossei supplied by deep branch of ulnar nerve
ACTIONS
 Palmar int. Adducts the fingers towards center of middle finger
 Dorsal int. Abducts the fingers towards center of middle finger
 All flexes M.P.J & extends inter phalangeal joints
MOVEMENTS OF THUMB
EXTENSION:
 extensor pollicislongus, extensor pollicis
brevis
FLEXION
 flexor pollicis longus,
 flexor pollicis brevis
ADDUCTION
 Adductor pollicis
ABDUCTION
 Abductor pollicis longus Abductor pollicis
brevis
OPPOSITION
 Movement of thumb across the palm so that its tip comes in contact with
tip of any other finger
 Produced by opponens pollicis
ANATOMICAL SNUFFBOX
 The anatomical snuffbox is the concavity on radial
side of wrist that appears when thumb is fully
extended
 It is bounded medially by extensor pollicis longus
and laterally by extensor pollicis brevis, and abductor
pollicis longus.
 Radial artery running in the floor of the snuffbox,
 Cutaneous branches ofradial nerve & cephalic vein
lie in the facia forming roof.
 Bony points palpable are : radial styloid, scaphoid trapezium, base of
thumb metacarpal
DUPUYTREN'S CONTRACTURE OR
PALMAR FIBROMATOSIS
 It is a fixed flexion contracture of the hand where the fingers bend
towards the palm and cannot be fully extended .
 It is caused by underlying contractures of the palmar fascia.
 The ring finger and little finger are commonly
affected. The middle finger may be affected in
advanced cases, but the index finger and the
thumb are nearly always spared.
 It progresses slowly and is usually painless.
 The tissues under the skin on the palm of the
hand thicken and shorten so that the tendons connected to the fingers
cannot move freely.
MALLET FINGER
 It is an injury of the extensor digitorum tendon of the
fingers at the distal interphalangeal joint (DIP).
 It results from hyperflexion of the extensor digitorum
tendon,
 Usually occurs when a ball (such as a softball,
basketball, or volleyball), while being caught, hits an outstretched
finger and jams it (by rupturing the extensor digitorum tendon).