ANATOMY IN A NUTSHELL. 123 



internal branches. The external branches stud (1) branches to the meninges 

 of the cord (2) to the posterior division of the spinal nerves. (3) to the anterior 

 divisions of the spinal nerves. These last two pass to the vessels of the skin. 

 glands of the skin, and the muscles of the hair. The internal branches divide 

 into an upper set and a lower set. The uppeb set, four or five, send branches 

 to the vertebrae and to ligaments and thoracic aorta and to the lungs. The 

 lower set give off the great splanchnic nerves. The great splanchnic 

 nerves come from the fifth to tenth and end in the semilunar ganglion. The 

 LESSER SPLANCHNIC nerve passes from the ninth and tenth and ends in the renal 

 or solar plexus. The least splanchnic comes from the last dorsal ganglion 

 to end in the renal plexus. The secretory fibers to the lower limbs, \ A.SO- 

 constrictor to vessels of the abdomen, pilo-motor to the circular fibers of the 

 rectum, and inhibitory fibers to the longitudinal muscles of the rectum de- 

 scend from the thoracic tothe lumbar region. Besides these there are afferenl 

 fibers (splanchnic sensory) which pass towards the posterior roots of the dor- 

 sal nerve. The lumbar ganglia are four, being set in front of the vertebrae. The 

 right cord of the sympathetic is behind the inferior v< na cava, the left behind 

 the peritoneum. White rami pass to these ganglia and gray rami pass from 

 them. The rami efferentes are first, external divisions and second, internal 

 divisions. The external divisions send gray rami to the lumbar nerves. The 

 internal divisions send (1) branches to the aorta. (2) hypogastric plexus 

 to the vertebra? and ligaments, and additional vaso constrictor fibers to the 

 renal vessels anel secretory fibers to the ve ssels of the lower limbs and i on- 

 BTRICTOR fibers to the vessels of the- lower limbs, pilo-motor and motor fibers 

 for the circular and ixhibitory fibers for the longitudinal muscles of the' rectum, 

 and motor fibers to the uterus and vas deferens and round ligament, and 

 VASO-MOTOR to the penis anel motor fibers to the circular and INHIBITORY 

 fibers for the longitudinal muscles of the bladd< r. 



LESSON ('Will. 



The sacral portion of the sympathetic ends in the ganglion of [mpar. It 

 has five ganglia which give off rami efft re nte s, (1) gray rami to the sacral nerves, 

 (2) branches to anastomose with the branch* s of the opposite side. <:!) branches 

 to plexuses on the middle sacral artery, (4) branches to plevic plexuses 

 branches from impar to tin coccyx and its ligament to the coccygeal gland. 

 There are no white rami in this portion of the sympathetic. They descend from 

 the dorsal region. Vaso-constrictor and secretory for the lower limbs, pilo- 

 motor for posterior part of the body com< from this region. "White' rami of 



sacral region" are' represented by their viscera] branches and ar< called 

 pe Ivic splanchnics. They contain motor fibers to the longitudinal muse 

 the bladder and for the longitudinal and inhibitory of the rectum ami to the 

 uterus and secretory to the' prostate gland and vaso-dilator to the penis. 



White' rami enter tin c< rvical sympathi tic from tin dorsal ; some term in. mi.' 

 in the superior ganglion, some in the middle ganglion, ami some in the lower 

 ganglion. The distribution of many an unknown. 



The sympathetic has three great prevertebral plexuses. First, the cardiac, 



