318 ANATOMY AND PHYSIOLOGY 



Special branches from cervical ganglia accompany arteries to 

 the head, larynx, pharynx, thyroid body, and heart. 



Special branches from thoracic ganglia accompany arteries to 

 lungs and esophagus in the thorax; stomach, liver, spleen, and 

 other viscera in the abdomen. (The branches passing through the 

 diaphragm to the solar plexus and abdominal viscera are called 

 splanchnic nerves three on each side.) 



Special branches from lumbar ganglia accompany arteries to 

 kidneys and pelvic organs. 



Special branches (or nerves) from the sacral ganglia accompany 

 arteries to the pelvic organs. 



The most important plexuses are the cardiac and the pulmon- 

 ary in the thorax, the celiac (solar) in the abdomen, and the hypo- 

 gastric in the pelvis (Fig. 205). 



The cardiac plexus lies underneath and behind the arch of the 

 aorta. Its branches supply the heart and lungs, following the 

 coronary and pulmonary arteries. 



The celiac (or solar) plexus is in the abdomen, in front of 

 the aorta, at the beginning of the celiac artery. It contains two 

 large ganglia the right and left celiac (semilunar) ganglia. This 

 plexus controls the vessels and the muscular coats of the abdominal 

 viscera; it has been called the abdominal brain. Thus it may be 

 understood how a severe blow over the plexus would produce a 

 very widespread and serious result. 



The hypo-gastric plexus is in front of the fifth lumbar vertebra 

 and divides to form the right and left pelvic plexuses, which are 

 distributed to all of the pelvic viscera (along with branches from 

 the sacral ganglia and lumbar-spinal nerves). 



Notes. Cardiac nerves from the cervical ganglia descend to the thorax, 

 entering the cardiac plexuses and supplying the heart and lungs. Certain 

 branches from the thoracic ganglia form splanchnic nerves which descend to 

 the abdomen, entering the celiac plexus and celiac ganglia, and supplying 

 digestive organs. Certain nerves from the lumbar ganglia descend to the 

 hypo-gastric plexus to enter the pelvic plexuses, supplying pelvic organs. 



FUNCTIONS OR PHYSIOLOGY OF THE SYMPATHETIC 



NERVES 



The work of organs supplied with sympathetic nerves is per- 

 formed involuntarily and unconsciously save in its results. Vis- 



