Question

What causes movement of food inside the alimentary canal?
A) Peristalsis
B) Pericardium
C) Rhythmic contraction and relaxation of heart
D) None of the above.

Answer 1

Alimentary canal is a muscular tube in which extends from mouth to the anus and. The movements of food inside the alimentary canal are involuntary and are produced as wave-like contractions.

Complete answer:
Let us analyse the options to find the correct answer.
Option A: Peristalsis are involuntary wave-like contractions of smooth muscles which help in the forward propulsion of food through the oesophagus and intestine. The food moves forwards due to the relaxation of smooth muscles. Hence, this is the correct option.
Peristalsis is initiated at the upper part of oesophagus as weak contractions and as it moves further to the distal end it becomes stronger. The wave travels the full length of the tube.
-The food is ahead of the wave in the stomach.
-One wave travels the complete oesophagus in 9 seconds.
-In the stomach the peristalsis helps to mix its contents, in the small intestine it helps in absorption of food and in the large intestine it serves as a cleansing agent.
Option B: Pericardium is a thin sac which surrounds and protects the heart. It is an irrelevant and incorrect option.
Option C: Rhythmic contraction and relaxation of heart is not involved in moving the food inside the alimentary canal. Hence, this is an incorrect option.
Option D: It's an incorrect option.

Therefore, the correct answer is option (A) Peristalsis.

Note:
-Peristalsis is topped when the stomach is full.
-Presence of fat can also inhibit the peristaltic movements.
-Peristalsis was described by Bayliss and Starling.
-Peristalsis is activated by the Parasympathetic nervous system (PNS).