PSYC340 Study Guide - Final Guide: Esophagus, Stratified Squamous Epithelium, Esophageal Hiatus
24 Jun 2018
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1. Describe the location and function of the pharynx.
A. Pharynx
A.I. When food is first swallowed, it passes from the mouth into the pharynx,
a funnel-shaped tube that extends from the internal nares to the
esophagus posteriorly and to the larynx anteriorly.
A.II. The pharynx is composed of skeletal muscle and lined by mucous
membrane, and is divided into three parts: the nasopharynx, the
oropharynx, and the laryngopharynx. The nasopharynx functions only in
respiration, but both the oropharynx and laryngopharynx have digestive
as well as respiratory functions.
A.III. Swallowed food passes from the mouth into the oropharynx and
laryngopharynx; the muscular contractions of these areas help propel
food into the esophagus and then into the stomach.
A.IV. Pharyngeal stage of deglutition. Moves bolus from oropharynx to
laryngopharynx and into esophagus; closes air passageways.
2. Describe the location, anatomy, histology and functions of the esophagus.
A. Esophagus
A.I. Is a collapsible muscular tube, about 25 cm (10 in.) long, that lies
posterior to the trachea. The esophagus begins at the inferior end of the
laryngopharynx, passes through the inferior aspect of the neck, and
enters the mediastinum anterior to the vertebral column.
A.II. Relaxation of upper esophageal sphincter. Permits entry of bolus from
laryngopharynx into esophagus.
A.III. Esophageal stage of deglutition (peristalsis). Pushes bolus down
esophagus.
A.IV. Relaxation of lower esophageal sphincter. Permits entry of bolus into
stomach.
A.V. Secretion of mucus. Lubricates esophagus for smooth passage of bolus.
A.VI. Esophageal hiatus
A.VII. Then it pierces the diaphragm through an opening called the esophageal
hiatus, and ends in the superior portion of the stomach
A.VIII. Histology of the esophagus
A.VIII.a. Mucosa, submucosa and muscularis
A.VIII.b. The mucosa of the esophagus consists of nonkeratinized
stratified squamous epithelium, lamina propria (areolar
connective tissue), and a muscularis mucosae (smooth muscle).
Near the stomach, the mucosa of the esophagus also contains
mucous glands. The stratified squamous epithelium associated
with the lips, mouth, tongue, oropharynx, laryngopharynx, and
esophagus affords considerable protection against abrasion and
wear and tear from food particles that are chewed, mixed with
secretions, and swallowed.
A.VIII.c. The submucosa contains areolar connective tissue, blood
vessels, and mucous glands
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Document Summary
Describe the location and function of the pharynx, pharynx. When food is first swallowed, it passes from the mouth into the pharynx, A. iii. a funnel-shaped tube that extends from the internal nares to the esophagus posteriorly and to the larynx anteriorly. The pharynx is composed of skeletal muscle and lined by mucous membrane, and is divided into three parts: the nasopharynx, the oropharynx, and the laryngopharynx. The nasopharynx functions only in respiration, but both the oropharynx and laryngopharynx have digestive as well as respiratory functions. Swallowed food passes from the mouth into the oropharynx and laryngopharynx; the muscular contractions of these areas help propel food into the esophagus and then into the stomach. Moves bolus from oropharynx to laryngopharynx and into esophagus; closes air passageways: describe the location, anatomy, histology and functions of the esophagus. Is a collapsible muscular tube, about 25 cm (10 in. ) long, that lies posterior to the trachea.
