Palmar aponeurosis
Encyclopedia
The palmar aponeurosis invests the muscles of the palm, and consists of central, lateral, and medial portions.
Its apex is continuous with the lower margin of the transverse carpal ligament, 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, those to the palm joining the skin at the furrow corresponding to the metacarpophalangeal articulations, and those to the fingers passing into the skin at the transverse fold at the bases of the fingers.
The deeper part of each slip subdivides into two processes, which are inserted into the fibrous sheaths of the Flexor tendons. From the sides of these processes offsets are attached to the transverse metacarpal ligament
.
By this arrangement short channels are formed on the front of the heads of the metacarpal bones; through these the Flexor tendons pass. The intervals between the four slips transmit the digital vessels and nerves, and the tendons of the Lumbricales
.
At the points of division into the slips mentioned, numerous strong, transverse fasciculi bind the separate processes together.
The central part of the palmar aponeurosis is intimately bound to the integument by dense fibroareolar tissue forming the superficial palmar fascia, and gives origin by its medial margin to the Palmaris brevis.
It covers the superficial volar arch, the tendons of the Flexor muscles, and the branches of the median and ulnar nerve
s; and on either side it gives off a septum, which is continuous with the interosseous aponeurosis, and separates the intermediate from the collateral groups of muscles.
; they are continuous with the central portion and with the fascia on the dorsum
of the hand.
Central portion
The central portion occupies the middle of the palm, is triangular in shape, and of great strength and thickness.Its apex is continuous with the lower margin of the transverse carpal ligament, 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, those to the palm joining the skin at the furrow corresponding to the metacarpophalangeal articulations, and those to the fingers passing into the skin at the transverse fold at the bases of the fingers.
The deeper part of each slip subdivides into two processes, which are inserted into the fibrous sheaths of the Flexor tendons. From the sides of these processes offsets are attached to the transverse metacarpal ligament
Transverse metacarpal ligament
Transverse metacarpal ligament can refer to:* Deep transverse metacarpal ligament* Superficial transverse metacarpal ligament...
.
By this arrangement short channels are formed on the front of the heads of the metacarpal bones; through these the Flexor tendons pass. The intervals between the four slips transmit the digital vessels and nerves, and the tendons of the Lumbricales
Lumbricales
Lumbricales can refer to:* Lumbricals of the hand* Lumbrical muscle...
.
At the points of division into the slips mentioned, numerous strong, transverse fasciculi bind the separate processes together.
The central part of the palmar aponeurosis is intimately bound to the integument by dense fibroareolar tissue forming the superficial palmar fascia, and gives origin by its medial margin to the Palmaris brevis.
It covers the superficial volar arch, the tendons of the Flexor muscles, and the branches of the median and ulnar nerve
Ulnar nerve
In human anatomy, the ulnar nerve is a nerve which runs near the ulna bone. The ulnar collateral ligament of elbow joint is in relation with the ulnar nerve. The nerve is the largest unprotected nerve in the human body , so injury is common...
s; and on either side it gives off a septum, which is continuous with the interosseous aponeurosis, and separates the intermediate from the collateral groups of muscles.
Lateral and medial portions
The lateral and medial portions of the palmar aponeurosis are thin, fibrous layers, which cover, on the radial side, the muscles of the ball of the thumb, and, on the ulnar side, the muscles of the little fingerLittle finger
The little finger, often called the pinky in American English, pinkie in Scottish English , or small finger in medicine, is the most ulnar and usually smallest finger of the human hand, opposite the thumb, next to the ring finger.-Muscles:There are four muscles that...
; they are continuous with the central portion and with the fascia on the dorsum
Dorsum
Dorsum is a Latin word. In science, it could mean:* Dorsum , the posterior side of an animal* Dorsum , a term used in astrogeology for a ridge* Theta Capricorni, a star on the back of the Goat...
of the hand.