Question

The tube starting at the mouth and ending at anus is called
A. Oesophagus
B. Food cavity
C. Alimentary canal
D. Elementary canal

Answer 1

Hint: We eat food to get energy for survival, growth and development. The food is chewed by teeth present in our mouth for better digestion. It is swallowed and digested in a tube-like structure which contains different structures in higher animals.

Complete answer:
The alimentary canal is a tube-like muscular structure. It has an opening called a mouth and the endpoint is called as anus. It starts from the mouth followed by various structures like pharynx, oesophagus, stomach, small intestine, large intestine and anus. This canal helps in the digestion of food with the help of secretions like HCl, gastric juice, intestinal juice, liver and pancreatic secretions etc. It is also called the gastrointestinal tract. In this canal, the food is digested and converted into its simple basic components and these components are absorbed through blood and lymph, the circulatory system. These substances include glucose, amino acids, minerals, vitamins, lipids etc.

Hence, the correct answer is option (C).

Additional information:
• The oesophagus is a tube-like structure that connects our throat or pharynx to the stomach. It only helps in the passage of food from the mouth to the stomach and no digestion takes place inside it. The food is passed in the forward direction with the help of peristaltic movements, which pushes the food into the stomach only in one direction.
• Food cavity and elementary canal are wrong terms with respect to mammals.

Note: The alimentary canal also contains two associated organs, which help in digestion of complex food materials. For example- our liver secretes bile that contains bile salts, which help in the emulsification of lipids. The pancreas secretes pancreatic juice, which helps in the digestion of different components of food like lipids, carbohydrates, proteins, etc.