Question

Which layer of the digestive tract controls digestive propulsion?

Answer 1

The muscularis externa is the layer of the digestive tract responsible for propulsion, using peristalsis to move food along the tract through smooth muscle contractions. This layer includes circular and longitudinal muscles, which are involved in mixing food and aiding digestion.

Step-by-step explanation:

The layer of the digestive tract that controls digestive propulsion is the muscularis externa or muscalaris. This particular layer in the small intestine is composed of a double layer of smooth muscle, specifically an inner circular layer and an outer longitudinal layer. Together, they facilitate the process of mechanical digestion, effectively mixing the food with digestive chemicals, and propelling the food through the digestive canal through rhythmic contractions known as peristalsis. In certain areas, like the mouth, pharynx, part of the esophagus, and externalsphincter, the muscularis is comprised of skeletal muscle, which allows for voluntary movement during swallowing and defecation. The stomach contains a third, oblique muscle layer to aid in its churning function, whereas the colon, with a similar structure as the small intestine, features the tenia coli that gives it a pouch-like appearance.

Answer 2

Out of the following given choices;

mucosa

serosa

submucosa

muscularis externa

The answer is muscularis externa. This layer is one of the 4 layers (tunics) of the GI tract. It is found beneath the submucosa and is composed of smooth muscles. The smooth muscles are responsible for the involuntary movements called peristalsis, that move food along the gastrointestinal tract.