330 PRACTICAL ANATOMY. 



THE SYMPATHETIC. 



The sympathetic serves to connect and bind the 

 several parts of the body sympathetically together. It 

 consists of a number of ganglia placed at each side of 

 the spinal column, and connected together by communi- 

 cating fibres. Each ganglion consists of an investing 

 fibrous membrane, and from this are given off delicate 

 fibrous septa, forming a neuroglia for the support of the 

 nerve cells and fibres. In each ganglion there are 

 groups of multipolar cells, naked axis-cylinders, the 

 fibres of Remak, and ordinary nerve-fibres. The ganglia 

 are connected together chain-like by interganglionic 

 nerve-fibres, and receive a number of branches from the 

 cerebro-spinal system. The branches of distribution 

 are frequently arranged in the form of plexuses on the 

 blood-vessels, and to the viscera. Excluding the sympa- 

 thetic ganglia associated with the fifth pair of nerves and 

 previously considered, there are three pairs of ganglia in 

 the cervical, twelve pairs in the dorsal, four pairs in the 

 lumbar, four or five pairs in the sacral, and one terminal 

 ganglion placed at the side of the third coccygeal ver- 

 tebra. The superior cervical ganglion lies on the ante- 

 rior surface of the rectus capitis anticus major, and 

 behind the deep cervical vessels. It sends branches 

 in every direction, and forms the carotid and cavernous 

 plexuses. Just above the anterior communicating artery, 

 the sympathetic chains communicate, forming the gan- 

 glion of Ribes. The superior cervical ganglion sends 

 off the superior cardiac nerve to the cardiac plexus. 

 The second or middle cervical ganglion, placed to 

 the side of the fifth cervical vertebra, rests upon the 

 anterior surface of the scalenus medius muscle. Its 

 most important branch is the middle cardiac, the largest 



