Longissimus

When the tendinous slips attached to the lumbar spines are cut, the deep medial surface of the thoracolumbar part of longissimus is exposed, revealing a variable number of slender accessory slips of origin. These come from the transverse processes of the lower thoracic vertebrae, mamillary processes of the lumbar vertebrae, or aponeurosis of the underlying transversospinalis. These may unite to form an independent muscle, transversalis dorsi or thoracis , with a separate insertion onto the upper two or three thoracic vertebrae. Similarly, accessory slips may be seen in the cervical section of the column arising from the roots of the transverse processes of the cervical vertebrae and forming, when more or less independent, the transversalis cervicis posterior minor .

The attachments of the components of the longissimus are subject to considerable variation. The costal attachments may be reduced either at the cranial or caudal end of the series; the longissimus cervicis may extend to the tenth or eleventh transverse process, or its slips may be reduced in number. The cranial section may be absent; it has been found divided into two parts. Its slips may be limited to the thorax or to the cervical vertebrae.

Slips detached from longissimus capitis have been observed originating from the transverse process of the atlas, or from the tendon of the cervical part of longissimus going to the atlas, and inserting onto the mastoid process.

Riferimenti dell’opera originale

Elenco riportato come compare nella fonte, senza normalizzazione dei formati bibliografici.

• Anson, B.J., Ed. (1966) Morris' Human Anatomy,12th ed., The Blakiston Division, McGraw-Hill Book Company, New York.
• Huber, C.G., Ed. (1930) Piersol's Human Anatomy,9th ed., L.B. Lippincott Company, Philadelphia.
• Latarjet, A. (1908) Testut's Traité D'Anatomie Humaine, 9th ed., G. Doin & Cie., Paris.
• Schaefer, E.A. Symington, J. and T.H. Bryce. Eds. (1923) Quain's Anatomy, 11th ed., Longmans, Green and Co., London.