The London Dissector (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1832 Excerpt: ...and posterior fissure, the posterior continued from the calamus scriptorius: on each side of the middle fissure is observed a lateral groove, on both surfaces of the chord: these grooves are superficial, and from them pass the anterior and posterior roots of the spinal nerves. Within the vertebral canal in the neck, is seen the Spinal Accessory Nerve, arising by small twigs from the side of the Spinal chord, as low down generally as the fourth or fifth cervical nerve: it then ascends between the ligamentum denticulatum and posterior roots of the three first cervical nerves, increasing in size by the addition of filaments, enters the foramen magnum, and passes forwards to accompany the par vagum. OF THE SPINAL NERVES. The Spinal Chord sends off twenty-nine pairs of spinal nerves. They consist of seven cervical, twelve dorsal, five lumbar, and five sacral pairs. Each of these nerves arises by two fasciculi, or bundles of filaments, one from the anterior, the other from the posterior surface of the chord: the ligamentum denticulatum intervenes between the two fasciculi, and they penetrate the dura mater by separate openings, receiving a tubular sheath from that membrane. The two fasciculi then pass outwards to the intervertebral foramen, the posterior swelling out into a small oval ganglion, within the foramen itself, and then immediately uniting with the anterior fasciculus, to'form the nerve. Each nerve, thus formed, passes out of the spinal canal betwixt the vertebrae, and divides after a short course, into two branches; one anterior, the other, posterior. A general view of the distribution of the spinal nerves may be usefully subjoined in this place, to complete the description of the nerves. 1. The Cervical Nerves consist of seven pairs, emerging between ...