The small intestine is responsible for the complete digestion of carbohydrates, proteins, and fats.

The length of the small intestine varies among animals based on their dietary habits. Herbivores consuming cellulose-rich diets, like grass, require longer intestines for more extensive digestion. In contrast, carnivores, such as tigers, with diets easier to digest, have shorter ...

The small intestine is the longest part of the alimentary canal because it is responsible for the majority of nutrient absorption. Its extensive coiling increases its surface area, facilitating efficient absorption of nutrients into the bloodstream.

The exit of food from the stomach is regulated by a sphincter muscle, which releases it in small amounts into the small intestine, allowing for controlled digestion and absorption.

Mucus secreted by gastric glands forms a protective layer over the stomach lining, preventing damage from the acidic environment and digestive enzymes present in the stomach.