Question

What are the $4$ layers of the alimentary canal?

Answer 1

Alimentary Canal:

The alimentary canal is a long tube of organs, including the oesophagus, stomach, and intestines, that runs from the mouth to the anus.

$4$ layers of the alimentary canal:

Serosa:

The serosa is the outermost layer made up of thin mesothelium.

Muscularis:

1. The muscularis consists of smooth muscles arranged in an inner circular and outer longitudinal layer.
2. The transverse muscles form only the innermost layer in the abdominal region.
3. Muscularis is responsible for peristalsis and digestion of food with juices.

Submucosa:

1. The submucosa consists of aortic connective tissue containing nerves, blood, and lymph vessels.

Mucosa:

1. It is the innermost layer composed of simple columnar epithelium.
2. It forms an irregular fold on an empty stomach called a rugae.
3. It also forms a small finger-like folding called the villi in the small intestine.