Final answer:
The muscular layer of the alimentary canal, or muscularis externa, is responsible for the movement and mechanical digestion of food.
Step-by-step explanation:
The muscular layer of the alimentary canal, also known as the muscularis externa, is responsible for the movement and mechanical digestion of food along the canal. It is made up of smooth muscle, with an inner circular layer and an outer longitudinal layer. The contractions of these layers help break down food, expose it to digestive chemicals, and propel it through the digestive system.