Which layer of the digestive tract controls digestive propulsion?

A. serosa
B. mucosa
C. submucosa
D. muscularis externa

Answer:

D. muscularis externa

Explanation:

The gastrointestinal tract or digestive tract consist of four main layers:

• Mucosa- consists of the epithelium together with glandular tissue and the lamina propria  (connective tissue)

• Submuscosa- consists of fibrous connective tissue with larger blood vessels, lymphatics, nerves..

• Muscularis externa-smooth muscle layer that consists of three layers, responsible for movement (propulsion) and physical break down of the food

• Serosa-consists of connective tissue continuous with the peritoneum.