Oregon Certified Nursing Assistant State Practice Exam

How does the immune system protect the body from disease?

1. Through nonspecific and specific immunity

2. Through hormones

3. Through digestion and elimination

4. Through inspiration and expiration

The correct answer is: Through nonspecific and specific immunity

The immune system provides protection against disease primarily through two mechanisms: nonspecific immunity and specific immunity. Nonspecific immunity serves as the first line of defense, responding quickly to a wide variety of pathogens such as bacteria, viruses, and fungi. This includes physical barriers like the skin and mucous membranes, as well as innate immune responses such as inflammation and phagocytosis, where immune cells engulf and destroy foreign invaders. Specific immunity, on the other hand, is a targeted response that develops over time following exposure to specific pathogens. This adaptive immunity involves the activation of lymphocytes, such as T cells and B cells, which can remember past infections. B cells produce antibodies that specifically target pathogens, while T cells help to destroy infected cells or assist other immune cells. The combination of these two types of immunity equips the body to recognize and remember pathogens, enabling it to mount an efficient response upon re-exposure, thereby protecting against disease. Understanding this dual mechanism is essential for grasping how the immune system functions effectively in maintaining health.