Question 1

Which of the following is NOT considered a physical barrier in the first line of defense against microbial invasion?

Accepted Answer

B and T lymphocytes

Question 2

A patient presents with a fever of unknown origin (FUO). Which mechanism is most likely responsible for the elevation in body temperature?

Accepted Answer

Pyrogens resetting the hypothalamic thermostat

Question 3

Which of the following best describes the role of the lymphatic system in immune defense?

Accepted Answer

It provides surveillance, recognition, and protection against foreign materials

Question 4

Which process is a hallmark of the second line of defense and involves the engulfment and destruction of pathogens by immune cells?

Accepted Answer

Phagocytosis

Question 5

A healthy immune system is responsible for all of the following EXCEPT:

Accepted Answer

Production of digestive enzymes

Question 6

Which of the following is TRUE regarding serum?

Accepted Answer

Serum is used in immune testing and therapy

Question 7

Which of the following antimicrobial products is BEST known for targeting viruses?

Accepted Answer

Interferons (IFN)

Question 8

Which of the following statements about inflammation is CORRECT?

Accepted Answer

Inflammation is a means for the body to maintain stability after injury

Question 9

Which of the following is a function of the third line of defense?

Accepted Answer

Long-term, highly specific immunity

Question 10

Which of the following is an example of a chemical barrier in the first line of defense?

Accepted Answer

Fatty acids on the skin

Question 11

A patient with a genetic defect in complement proteins would MOST likely have impaired:

Accepted Answer

Ability to target membranes of pathogens

Question 12

Which of the following is the correct sequence of the three lines of defense?

Accepted Answer

Physical barriers → Innate immunity → Adaptive immunity

Question 13

Which immune cells are primarily responsible for the highly specific responses in the third line of defense?

Accepted Answer

B and T lymphocytes

Question 14

Which of the following is a function of antimicrobial peptides?

Accepted Answer

Directly kill all manner of microbes

Question 15

Which of the following is a plausible consequence of immune system failure to recognize 'self' markers?

Accepted Answer

Development of autoimmune disorders

Question 16

Which of the following best explains why fever can be beneficial during infection?

Accepted Answer

It inhibits the replication of temperature-sensitive microbes

Question 17

Which of the following is TRUE regarding the relationship between the circulatory and lymphatic systems?

Accepted Answer

The lymphatic system provides immune surveillance, while the circulatory system transports blood cells

Question 18

Which of the following is a correct description of an antigen?

Accepted Answer

Any cell, particle, or chemical that induces a specific immune response

Question 19

Which of the following mechanisms is LEAST likely to be involved in the second line of defense?

Accepted Answer

Antibody production by B cells

Question 20

A patient is exposed to a novel pathogen. Which line of defense will provide the most specific and long-lasting protection?

Accepted Answer

Third line of defense

Host Defenses I: Mechanisms of the Immune System

Study Guide - Practice Questions