Henry Gray (18251861). Anatomy of the Human Body. 1918.
spinous processes of the contiguous vertebræ, one on either side of the interspinal ligament. In the cervical region they are most distinct, and consist of six pairs, the first being situated between the axis and third vertebra, and the last between the seventh cervical and the first thoracic. They are small narrow bundles, attached, above and below, to the apices of the spinous processes. In the thoracic region, they are found between the first and second vertebræ, and sometimes between the second and third, and between the eleventh and twelfth. In the lumbar region there are four pairs in the intervals between the five lumbar vertebræ. There is also occasionally one between the last thoracic and first lumbar, and one between the fifth lumbar and the sacrum.
The Extensor coccygis is a slender muscular fasciculus, which is not always present; it extends over the lower part of the posterior surface of the sacrum and coccyx. It arises by tendinous fibers from the last segment of the sacrum, or first piece of the coccyx, and passes downward to be inserted into the lower part of the coccyx. It is a rudiment of the Extensor muscle of the caudal vertebræ of the lower animals.
The Intertransversarii (Intertransversales) are small muscles placed between the transverse processes of the vertebræ. In the cervical region they are best developed, consisting of rounded muscular and tendinous fasciculi, and are placed in pairs, passing between the anterior and the posterior tubercles respectively of the transverse processes of two contiguous vertebræ, and separated from one another by an anterior primary division of the cervical nerve, which lies in the groove between them. The muscles connecting the anterior tubercles are termed the Intertransversarii anteriores; those between the posterior tubercles, the Intertransversarii posteriores; both sets are supplied by the anterior divisions of the spinal nerves (Lickley1). There are seven pairs of these muscles, the first pair being between the atlas and axis, and the last pair between the seventh cervical and first thoracic vertebræ. In the thoracic region they are present between the transverse processes of the lower three thoracic vertebræ, and between the transverse processes of the last thoracic and the first lumbar. In the lumbar region they are arranged in pairs, on either side of the vertebral column, one set occupying the entire interspace between the transverse processes of the lumbar vertebræ, the Intertransversarii laterales; the other set, Intertransversarii mediales, passing from the accessory process of one vertebra to the mammillary of the vertebra below. The Intertransversarii laterales are supplied by the anterior divisions, and the Intertransversarii mediales by the posterior divisions of the spinal nerves (Lichley, op. cit.).
The Rectus capitis posterior major (Rectus capitis posticus major) arises by a pointed tendon from the spinous process of the axis, and, becoming broader as it ascends, is inserted into the lateral part of the inferior nuchal line of the occipital bone and the surface of the bone immediately below the line. As the muscles of the two sides pass upward and lateralward, they leave between them a triangular space, in which the Recti capitis posteriores minores are seen.
The Rectus capitis posterior minor (Rectus capitis posticus minor) arises by a narrow pointed tendon from the tubercle on the posterior arch of the atlas, and, widening as it ascends, is inserted into the medial part of the inferior nuchal line of the occipital bone and the surface between it and the foramen magnum.
Note 1. Journal of Anatomy and Physiology, 1904, vol. xxxix. [back]