Chapter 35, Problem 1RQ

Distinguish susceptibility from resistance, and innate from acquired immunity. Why are these traditionally recognized types of immunity now more difficult to distinguish?

Summary Introduction

To distinguish: Susceptibility and resistance; innate and acquired immunity. Reason for the difficulty in distinguishing the traditionally recognized types of immunity.

Introduction: The immune system is a complex system that is essential for the survival of humans. The immune system is divided into two types –the innate immune system and the adaptive immune system. The immune system provides protection from foreign bodies.

Explanation of Solution

Susceptibility: Susceptibility is the term that represents the failure to remove the microbe before the occurrence of infection.

Resistance: The ability to prevent infection from a biological viewpoint is called resistance.

Innate immunity: Innate immunity gives protection immediately after the entry of pathogens into the human body. No need for previous exposure to the pathogen.

Acquired immunity: This type of immunity is adapted after the exposure to a pathogen and thus, it is also called adaptive immunity. Acquired immunity works on the basis of memory of previous exposure.

It is difficult to distinguish between the above said traditionally recognized types of immunity because those terms are not absolute. The susceptibility and resistance depend upon the host’s age, health, and environmental exposure rather than the mechanism of defense.