The Pharynx.
—The pharynx is that part of the alimentary canal, which is placed behind, and communicates with the nose, mouth and larynx. It is a muscular, membranous tube which extends from the back of the mouth and under surface of the skull to the level of the cricoid cartilage or to a point between the fifth and sixth cervical vertebrae.
The pharynx is about four and one-half inches in length.
Seven openings communicate with it, as follows:
Two posterior nares, two eustachian tubes, mouth, larynx, esophagus.
The Esophagus.
—The esophagus or gullet is a muscular canal about nine or ten inches in length, extending from the pharynx to the stomach.
It begins at a point between the fifth and sixth cervical vertebrae and descends along in front of the spine through the posterior mediastinal space, passes through the diaphragm, and entering the abdomen, terminates in the stomach wall at a point opposite the tenth dorsal vertebra.
At its commencement it is placed in the median line and gradually inclines to the left as it passes forward to the esophageal opening to the diaphragm.
The esophagus is from one-half to an inch in diameter.