MCAT Content / Digestive System / Muscular Control

Muscular control

Topic: Digestive System

The digestive system has three muscular sphincters that control the movement of food contents into the digestive system. Peristalsis movement also occurs in the digestive system that helps in the movement of food.

The smooth muscle in the walls of the digestive tract contract and relax involuntarily. This is known as peristalsis that helps in the movement of the food in the digestive tract.

The cardiac sphincter is present at the junction of the esophagus and stomach that regulates the movement of food content between the esophagus and stomach. The pyloric sphincter is present at the junction of the stomach and small intestine that regulates the movement of food content between the stomach and the small intestine. The anal sphincter is present at the junction of rectum and anus that regulates the defecation of feces via the anus. Other sphincters control the movement of bile from the gall bladder and the pancreas to control enzymes added to the digestive system.


Practice Questions

MCAT Official Prep (AAMC)

Practice Exam 4 B/B Section Passage 7 Question 37


Key Points

• The muscular control in the digestive tract involves the peristalsis movement that is involuntary contraction and relaxation movement of the smooth muscles present in the wall of the digestive tract.

• Three sphincters cardiac sphincter, pyloric sphincter, and anal sphincter are also circular muscles that control the movement of contents in the digestive tract.

Key Terms

sphincter: a circular smooth muscle that regulates the movement of content at the junction of two parts or an opening.

involuntary: the functions that are not under the control of our will and are controlled automatically by the nervous system

defecation: removal of feces from the body via the anus

feces: waste food which has not been digested

esophagus: a tube-like muscular organ that transports the bolus to the stomach for further digestion

peristalsis: contraction in the smooth muscle of the esophagus that helps in the transport of food

smooth muscle: involuntary muscle tissue which contracts slowly and automatically

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