Layers of Small Intestine:
- The mucosa is made up of simple columnar epithelium. It secretes digestive enzymes and hormones.
- The submucosa is the layer of dense, irregular connective tissue or loose connective tissue that supports the mucosa.
- The muscularis is a region of muscle adjacent to the submucosa membrane. It is responsible for gut movement, or peristalsis. It usually has two distinct layers of smooth muscle: circular and longitudinal.
- The serosa is a smooth membrane consisting of a thin layer of cells that secrete serous fluid and a thin layer of connective tissue. Serous fluid is a lubricating fluid that reduces friction from the movement of the muscularis.
The muscularis is a region of muscle adjacent to the submucosa membrane. It is responsible for gut movement, or peristalsis. It usually has two distinct layers of smooth muscle: circular and longitudinal. Hence, the correct answer is option d.
View full answer