In the alimentary canal the swallowed food moves downwards because of

Options

A. the contraction of muscles in the wall of food pipe
B. the flow of fluid material taken with the food
C. gravitational pull
D. force provided by the muscular tongue

Explanation

**Step-by-Step Solution:**

1. **Understanding the Alimentary Canal**: The alimentary canal is a long tube that runs from the mouth to the anus, where food passes through various organs for digestion and absorption.

2. **Swallowing Process**: When food is swallowed, it enters the esophagus (also known as the food pipe).

3. **Muscle Contractions**: The walls of the esophagus are lined with muscles that contract and relax in a coordinated manner. This process is known as peristalsis.

4. **Peristalsis Explained**: Peristalsis is a wave-like movement that helps push the food downwards through the esophagus and into the stomach. The muscles contract behind the food bolus (the mass of food) and relax in front of it, allowing the food to move downwards.

5. **Conclusion**: The primary reason swallowed food moves downwards in the alimentary canal is due to the contractions of the muscles in the walls of the food pipe (esophagus), which create peristaltic waves.

**Final Answer**: The swallowed food moves downwards in the alimentary canal because of the contractions of muscles in the walls of the food pipe.

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