Final answer:
The muscularis of the GI tract contains two layers of smooth muscles: the outer circular layer and the inner longitudinal layer.
Step-by-step explanation:
The statement is true. The muscularis of the GI tract contains two layers of smooth muscles: the outer circular layer and the inner longitudinal layer. The contractions of these layers promote mechanical digestion, expose more of the food to digestive chemicals, and move the food along the canal. The muscularis in the small intestine is made up of a double layer of smooth muscle: an inner circular layer and an outer longitudinal layer.