Chapter 12, Problem 17Q

Summary Introduction

To determine:

Smokers have a high chance of respiratory infection and smoking has to invoke aspects of the first line of defense.

Concept introduction:

The immune system includes three lines of defense against foreign particle. It is a network of cells, tissues, and organs that protect the body from infection and disease. It has three lines of a defense system against pathogen first, a second and third line of the defense system.