ANATOMY IN A NUTSHELL. 317 



The next part of the alimentary canal is called the oesophagus (Plate CXLVI) 

 which extends from the spinous process of the sixth cervical vertebra to the 



cardiac end of the stomach opposite the spinous process of the ninth dorsal. It 

 consists of three coats, an outer or muscular, a middle or areolar, and an internal 

 or mucous. All of the alimentary canal above the diaphragm has three coats, 

 and all below it has four coats, these three just mentioned and a serous coat or 

 peritoneum. 



The oesophagus (Plate CXLVI) in the neck, is boundeb! in front by the 

 trachea, the thyroid gland, and the thoracic duct. On each side by the common 

 carotid artery, the lateral part of the lobes of the thyroid gland, and the re- 

 current laryngeal nerve. Behind by the vertebral column and the Longus colli. 



In the thorax it is bounded in front by the trachea, arch of the aorta, left 

 common carotid artery, left subclavian artery, left bronchus, pericardium, and 

 Diaphragm. Behind by the vertebral column, Longus colli, vena azygos minor, 

 right intercostal arteries, thoracic duct, aorta, and the abdominal aorta. On 

 the right side by the right lung and pleura, vena azygos major, and the thoracic 

 duct. On the left side by the left lung and pleura, and thoracic aorta. The 

 left pneumogastric and right pneumogastric surround the oesophagus, the right 

 being situated behind it and the left in front, forming the plexus of Gula? in the 

 muscular coat. 



The muscular coat consists at first of three perpendicular bands, the anterior 

 one being attached to the posterior part of the cricoid cartilage and the lateral 

 ones being continuous with the Inferior constrictor of the pharynx. These 

 three bands gradually blend and make a circular muscular band around the 

 oesophagus. The next coat is the circular coat which is continuous with the 

 fibers of the Inferior constrictor and at the upper part of the oesophagus they are 

 parallel and at the lower part they are parallel, but in the intermediate portion 

 they are oblique. The upper ones are striped or voluntary muscles, while the 

 lower ones are involuntary. The glands of the esophagus are compound race- 

 mose glands which empty by long tubes on the mucous membrane. 



The oesophagus (carrying eatables) or gullet is a tube connecting the pharynx 

 and stomach. It is about ten inches long. The blood supply is from the Infer- 

 ior thyroid which comes from the thyroid axis of the subclavian; branches from 

 t he d( sc< oding thora< ic aorta ; and from the gast i ic branches of the coeliac axis 

 of abdominal aorta. The nerve supply is from th< pneumogastric and sympa- 

 thetic. They form a plexus in which are groups of ganglion-cells between the 

 two layers of the muscular coats, and also a second plexus in the submucous 

 tissue. 



