Anatomy Atlases: Illustrated Encyclopedia of Human Anatomic Variation: Opus I: Muscular System: Alphabetical Listing of Muscles: S: Splenius

Anatomy Atlases(tm) : A digital library of anatomy information

Illustrated Encyclopedia of Human Anatomic Variation: Opus I: Muscular System: Alphabetical Listing of Muscles: S

Splenius

Ronald A. Bergman, PhD
Adel K. Afifi, MD, MS
Ryosuke Miyauchi, MD
Peer Review Status: Internally Peer Reviewed

The absence of this muscle has been reported at least twice (Testut and LeDouble). Its origins may be displaced proximally by one or two vertebrae, and frequently the origins do not correspond on both sides. The spinal origin may extend to the cranial end of ligamentum nuchae. The muscle is sometimes separated into two parts, the superior part overlapping the inferior at its origin. Slips joining longissimus capitis, iliocostalis, or levator scapulae are sometimes found. Splenius cervicis may send a slip to the levator scapulae (Wood). The sheet may be broken up into separate parts forming a mastoid and an occipital division.

Accessory slips, in rare cases, pass superficial to serratus posterior superior and may be more or less connected with splenius. One such slip, rhomboatloideus or splenius colli accessorius, arises from the lower cervical and upper thoracic spines with serratus posterior superior, passes superficial to that muscle along the border of splenius, and inserts on the transverse process of the atlas. Its reported frequency is about 8% (LeDouble). When this slip inserts onto the occipital bone or mastoid process it is named splenius capitis accessorius. In another report, splenius colli accessorius or rhomboaxoides (Macalister) was found arising from the fascia of rhomboideus minor and serratus posterior inferior.

The splenius represents a superficial prolongation of the lateral column of muscle to the head. Its attachment to the spinous processes of the vertebrae is probably due to a dorsal extension of the muscle, associated with a change in the direction of its fibers. This is supported by the observation that the nerve supply of splenius is derived from lateral branches of the posterior division of spinal nerves, which are limited to cervical muscles.

Syn.: mm. Bauschmuskeln, Riemenmuskeln.

References

Knapp,E. (1966) Über eine seltene Varietät der Nakenmuskulatur (M. splenius accessorius). Anat. Anz. 118:178-180.

LeDouble, A.F. (1897) Traité des Variations du Système Musculaire de l'Homme et Leur Signification au Point de Vue de l'Anthropologie Zoologique. Libraire C. Reinwald, Schleicher Freres, Paris.

Macalister, A. (1875) Observations on the muscular anomalies in the human anatomy. Third series with a catalogue of the principal muscular variations hitherto published. Trans. Roy. Irish Acad. Sci. 25:1-130.

Miyazima, S., Okabe, N., and Kitagawa, Y. (1960) Three cases of the anomalies of the M. splenius. Kurume Igakkai Zasshi 23:1443-1448. In Japanese.

Nishi, S. (1918) Ein Beiträg zur Anatomie des M. ileocostalis (sic): Fasciculi intercostales dorsale beim Mensche. Arbeite aus Anat. Inst. Sendai 1:1-5.

Takeshige, A., Hirohashi, T. Mihashi, N., Oribe, H., and H. Tsuda. (1959) On the variation of the M. splenius. Kurume Igakkai Zasshi 22:33-36. In Japanese.

Testut, L. (1884) Les Anomalies Musculaires Chez l'Homme Expliques par l'Anatomie Comparée. Masson, Paris.

Wood, J. (!867) On human muscular variations in their relation to comparative anatomy. J. Anat. Physiol. 1:44-59.

Section Top |Title Page

Anatomy Atlases is curated by Michael P. D'Alessandro, M.D. and Ronald A. Bergman, Ph.D.

Please send us comments by filling out our Comment Form.

"Anatomy Atlases", the Anatomy Atlases logo, and "A digital library of anatomy information" are all Trademarks of Michael P. D'Alessandro, M.D.

Anatomy Atlases is funded in whole by Michael P. D'Alessandro, M.D. Advertising is not accepted.

Your personal information remains confidential and is not sold, leased, or given to any third party be they reliable or not.

The information contained in Anatomy Atlases is not a substitute for the medical care and advice of your physician. There may be variations in treatment that your physician may recommend based on individual facts and circumstances.

URL: http://www.anatomyatlases.org/