Palmaris longus muscle

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Palmaris longus muscle
Muscular Palmarislongus.png
origin
Humerus ( epicondylus medialis humeri ) and forearm fascia ( fascia antebrachii )
approach
Palmar aponeurosis and flexor retinaculum.
function
Tension the palmar fascia , flexion of the wrist , slight flexion of the elbow joint
Innervation
Median nerve
Spinal segments
C7, C8, Th1

The musculus palmaris longus ( Latin for "long palm muscle") is a superficial muscle on the front (flexor side) of the forearm . It arises from the medial epicondyle of the upper arm bone ( humerus ) and from the inside of the forearm fascia ( fascia antebrachii ). The slender muscle starts in the aponeurosis palmaris , a tendon sheet under the skin of the palm, and on the retinaculum flexorum . The palmaris longus muscle is involved in flexing the wrist and tensions itPalmar aponeurosis .

The musculus palmaris longus arises from the embryonic organ system ( blastema ) of the superficial finger flexor muscle ( musculus flexor digitorum superficialis ). In humans, it is one of the muscles with the most common variants of shape, origin and insertion. In about 13% of the cases, the muscle is completely absent. In this case a relative enlargement of the musculus palmaris brevis can be observed.

The palmaris longus and flexor carpi radialis muscles - both on the right in the picture - during the resection of a lipoma of the forearm.

The palmaris longus muscle is the most superficial of all flexors in the wrist, which makes its tendon (if present) very prominent in the middle of the wrist when the closed hand is flexed (fist closure).

In domestic animals (horses, cattle, pigs, dogs and cats) the muscles are not developed.

Individual evidence

  1. ↑ a b c T. Lanz, W. Wachsmuth: Practical Anatomy. Poor . 2nd Edition. Springer Verlag, Berlin / Heidelberg 2004, ISBN 3-540-40571-2 , p. 180.
  2. ↑ a b c M.M. Ito, M. Aoki, K. Kida, K. Kumaki, S. Tanaka: Length and width of the tendinous Portion of the palmaris longus: a cadaver study of adult japanese . In: Journal of Hand Surgery , 26A, 2001, pp. 706-710. PMID 11466648 .
  3. ↑ I. Dylevsky: ontogenesis of the palmar muscle in it . In: Folia Morphol. (Praha) 17 (1), 1969, pp. 23-28. PMID 5763142 .
  4. ↑ AF Reimann, EH Daseler, BJ Anson, LE Beaton: The palmaris longus muscle and tendon. A study of 1600 extremities . In: The Anatomical Record , 89, 1944, pp. 495-505. doi: 10.1002 / ar.1090890408 .