Chapter 43, Problem 43.1CR

In what ways does innate immunity protect the mammalian digestive tract?

Summary Introduction

To review: The ways to protect the mammalian digestive tract by the innate immunity.

Concept introduction:

Innate immunity is the natural immunity present in all animals. It is the primary defense mechanism.

Explanation of Solution

Innate immunity has two major defense mechanisms. They are barrier defense and internal defense. Barrier defense consists of skin, mucous membrane, and secretions. Internal defense consists of phagocytic cells, natural killer cells, inflammatory response, and antimicrobial proteins. Barrier defense stops the entry of pathogens into the host. Internal defense recognizes the pathogens, engulf them, and destroy them.

Conclusion

In mammalian digestive tract, the salivary secretion contains an enzyme called lysozyme. Lysozyme enzyme degenerates the bacterial cell wall. The mucus secreted by the digestive tract helps in trapping the bacteria. The stomach secretes HCl; hence, the gastric juice will be acidic in nature. This acidic nature of gastric juice destroys all the bacteria. The cells are tightly packed and prevent the entry of pathogen. This also provides a physical barrier to the pathogens.