Question

what unique feature(s) do/does the muscularis layers of the GI tract exhibit in the: esophagus
stomach
large Intestine

Answer 1

Gastointestinal tract is basically a muscular tube which help the ingestion and digestion of food, the absorption of nutrients and water, and the elimination of waste products. Although it has similar histological stucturs, the layers of the GIT has some unique features in different part of the tract according to its function.

Unique feature of the muscularis layers of the esophagus

The most of the muscle of the upper one third of the esophagus is striated muscle which transform to smooth muscle at the lower part. It helps in the peristaltic movement of esophagus to carry food to stomach.

Unique feature of the muscularis layers of the Stomach

The structure of the muscularis externa of stomach is unique due to the presence of three layers. They are inner oblique, middle circular, and outer longitudinal layers. These layers helps the food to break up and mix with gastric juices by crunching movements.

Unique feature of the muscularis layers of the large intestine

The muscularis layer of large intestine consist of teniae coli, which is three thick bands of muscles instead of longitudinal muscle layers of other parts of GI tract. The teniae coli contract and gives segment like appearance to the large intestine called haustra which help water absorption from the food by slow movement through each segments.