Question

List the four tissue layers of GI tract in order from most superficial to deep?

Answer 1

Ans) The Gastrointestinal tract has 4 layers from deep to superficial. They are

1. Mucosa

2. Submucosa

3. Muscularis

4. Serosa

Mucosa : It is formed by columnar epithelium.
In small intestine and stomach the layer of mucosa is comprised of secretions of digestive juices. Basically, in small intrestine the layer of mucosa is assoiated with microvilli which are finger like projections performing the function of increasing the surface area for absorption.

Submucosa :
Submucosal enteric layer consist of neural plexus which regulate blood flow and secretions of GI. Also, it consist of many glands which with the help of duct open into lumen.

Muscularis :
Muscularis consist of skeletal and smooth muscle tissue.
Skeletal muscle tissue is found in upper oesophagus, pharynx, mouth and canal lower portion
Smooth muscle tissue is found in remaining parts of Gastrointestinal tract.

Serosa : It is the superficial layer of GI. Also, it secretes serous peritoneal liquid.

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