. Anatomy, descriptive and applied. Anatomy. 1064 THE NERVE SYSTEM MIDDLE CEHVI- In the neck the ganglia are situated in front of the transverse processes of the vertebra; in the thoracic region, in front of the heads of the ribs; in the lumbar region, on the sides of the bodies of the spifOL vertebrae; and in the sacral region, in front of the sacrum. Connections with the Spinal Nerves.—Communications are established between the sym- pathetic and spinal nerves through' what are known as gray and white rami communi- cantes (Fig. 786), the gray rami conveying sympathetic fibres into the spinal
. Anatomy, descriptive and applied. Anatomy. 1064 THE NERVE SYSTEM MIDDLE CEHVI- In the neck the ganglia are situated in front of the transverse processes of the vertebra; in the thoracic region, in front of the heads of the ribs; in the lumbar region, on the sides of the bodies of the spifOL vertebrae; and in the sacral region, in front of the sacrum. Connections with the Spinal Nerves.—Communications are established between the sym- pathetic and spinal nerves through' what are known as gray and white rami communi- cantes (Fig. 786), the gray rami conveying sympathetic fibres into the spinal nerves, and the white rami transmitting afferent and efferent fibres to the sym- pathetic. Each spinal nerve receives a gray ramus com- municans from the gangliated cord of the sympathetic, but white rami are not supplied by all the spinal nerves. The white rami are derived from the first thoracic to the first lum- bar, inclusive, while the visceral branches which run from the second, third and fourth sacral nerves directly to the pelvic plex- uses of the sympathetic belong to this category. The majority of the fibres which spring from the sympathetic ganglia are amyelinic (_^6res of Remak); the fibres which reach the sympa^ thetic through the white ramus communicans are myelinated. The branches of distribution, or sympathetic nerves, derived from the gangliated cords from the prevertebral plexuses, and also from the smaller ganglia, are principally destined for the bloodvessels and thoracic and abdominal viscera, supplying the involuntary muscle fibres of the coats of the vessels and the hollow viscera, and the se- creting cells, as well as the Fio. surface of the spinal cord, showing the mUSCular COatS of the Vessds in Bpinal nerves and their connections with the sympathetic trunk on j^q o-landular VlSCera. 1 ney one side. (Testut.) -^ i> n. , ^ a: j. consist of efferent and aiierent fibres, for the origin and course of which see pages 1014 and 1015 (Fig. 7
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectanatomy, bookyear1913
