Function: muscular tube that delivers food and liquid from oropharynx to the stomach.
Function: forms the number of longitudinal folds. As bolus of food passes down the esophagus, the folds flatten out, resulting a localized dilation of the lumen.
Composition: moderately dense irregular connective tissue, blood vessels, lymphatic vessels, nerve network, esophageal glands proper.
Function: propels the contents by shortening the tube.
Composition: the upper 1/3 - striated muscle that circular layer is thickened to form pharyngoesophageal sphincter, the middle third - striated muscle and smooth muscle, the distal third - smooth muscle.
Composition: in thoracic cavity: loose connective tissue, in abdominal cavity: serosa - loose connective tissue covered by simple squamous epithelium - mesothelium, white adipose tissue.
Function: mucus secretion.
Location: lamina propria of the mucosa