HISTOLOGICAL STRUCTURE OF ESOPHAGUS

Histology Of ESOPHAGUS

It is comprised of the following layers

MUCOSA: In the relaxed state esophageal mucosa is deeply folded.

a. The lumen of esophagus is lined by a thick stratified squamous epithelium.

b. Underlying lamina propria is relatively condensed and contains scattered lymphoid aggregations, blood vessels, nerves and lymph vessels. It also contains mucous glands called cardiac glands because of their resemblance to the cardiac glands of stomach.

c. The muscularls mucosa is comprised of mainly longitudinal muscle coat while an outer longitudinal layer and an inner circular layer of smooth muscle fibers become especially distinguished in the lower third of esophagus.

II. SUBMUCOSA: It consists of loose areolar C.T. containing larger blood vessels, lymphatics and few parasympathetic ganglion cells (Meissner's or submucosal plexus). The submucosa also contains small mucous glands, which aid lubrication and are mainly confined to lower third of esophagus.

III. MUSCULARIS EXTERNA: Mixed skeletal (but Involuntary) and smooth muscles are

present in two distinct layers; inner circular and outer longitudinal. In upper one-fourth only skeletal muscle Is present, in middle two-fourth both types of muscle are found and in lower one-fourth only smooth muscle is seen. The layers of muscularis are separated by loose connective .tissue containing Auerbach's or myenteric plexus of nerves.

IV. FIBROSA: The upper ⁵/« of esophagus is covered by loose supporting connective tissue, which conducts blood vessels and nerves and is termed as fibrosa. The lower V* is covered by visceral layer of peritoneum (mesothellum or serosa).