Page 577 - Atlas of Histology with Functional Correlations

Normally contains an inner circular and an outer longitudinal smooth muscle

layer
Myenteric nerve plexus located between inner and outer smooth muscle
layers
Myenteric nerve plexus controls motility of smooth muscles in muscularis
externa

Serosa

Most superficial layer of abdominal portions of the digestive tract
Thin layer of connective tissue and mesothelium that cover the visceral
organs
Covers abdominal esophagus, stomach, small intestine, and anterior wall of

the colon

Adventitia

Consists only of connective tissue layer without mesothelium lining
Covers thoracic part of the esophagus and posterior wall of the ascending and
descending colon

ESOPHAGUS

Soft tube that extends from the pharynx to stomach, posterior to the trachea

Penetrates the diaphragm, and a short portion is in the abdominal cavity
before entering stomach
In the thoracic cavity, outside layer is connective tissue or adventitia

Lumen lined with moist, nonkeratinized stratified squamous epithelium
Mucous esophageal glands are in both the lamina propria and the submucosa
for lubrication
In the upper third, muscularis externa contains skeletal muscle
In the middle, both smooth and skeletal muscles are found in muscularis

externa
In the lower third, muscularis externa contains smooth muscle only

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