An epidemic is identified when $$\text{Actual cases} \u003e \text{Expected cases}.$$

Question 1

Which of the following best describes an epidemic, as illustrated in the provided graph and map images?

Accepted Answer

A disease that occurs in a higher-than-expected number of cases within a specific region over a short period.

Question 2

Which physical barrier is most effective at preventing the entry of pathogens, based on its structure and function?

Accepted Answer

The skin, because it is composed of multiple layers of tightly packed cells and is dry.

Question 3

Which chemical secreted by the skin acts to directly destroy bacterial cell walls?

Accepted Answer

Lysozyme

Question 4

What is the primary function of the lacrimal apparatus in innate immunity?

Accepted Answer

To secrete lysozyme and wash the surface of the eye with tears.

Question 5

Which of the following is NOT a mechanism by which the microbiome protects the host from pathogens?

Accepted Answer

Directly increasing the permeability of blood vessels.

Question 6

Which secretion in the digestive system is responsible for sequestering iron, making it unavailable for microbial use?

Accepted Answer

Gastroferritin

Question 7

A patient presents with increased eosinophils in their blood. Which condition is most likely indicated?

Accepted Answer

Allergy or parasitic worm infection

Question 8

Which leukocyte is primarily responsible for phagocytosis and is a key player in the body's second line of defense?

Accepted Answer

Neutrophil

Question 9

During phagocytosis, which step involves the movement of phagocytes toward the site of infection in response to chemical signals?

Accepted Answer

Chemotaxis

Question 10

Which Toll-like receptor (TLR) is most likely to recognize flagellin, a component of bacterial flagella?

Accepted Answer

TLR5

Question 11

Which of the following best describes the action of Type I interferons (alpha and beta) in viral infections?

Accepted Answer

They stimulate neighboring cells to produce antiviral proteins, inhibiting viral replication.

Question 12

Which process is characterized by redness, heat, swelling, and pain, and is a nonspecific response to tissue damage?

Accepted Answer

Inflammation

Question 13

What is the primary outcome of vasodilation during acute inflammation?

Accepted Answer

Increased delivery of blood clotting proteins and phagocytes to the site of injury.

Question 14

Which pyrogen is most likely to trigger fever by acting on the hypothalamus?

Accepted Answer

Bacterial toxins

Question 15

Which equation best represents the relationship between the number of cases and the expected number of cases in identifying an epidemic?

Accepted Answer

An epidemic is identified when $$	ext{Actual cases} \u003e 	ext{Expected cases}.$$

Question 16

Which of the following is a function of antimicrobial peptides in innate immunity?

Accepted Answer

They act against a variety of microbes and are present in skin, mucous membranes, and neutrophils.

Question 17

A patient with a chronic inflammatory response is at risk for which of the following?

Accepted Answer

Long-lasting tissue damage that can cause disease.

Question 18

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

Accepted Answer

Fever enhances the effects of interferons and inhibits growth of some microbes.

Question 19

Which of the following is a correct sequence of events during acute inflammation after a cut and infection?

Accepted Answer

Bacteria invade, damaged cells release mediators, vasodilation and increased permeability, phagocytes migrate, tissue repair.

Question 20

Which of the following is NOT a characteristic of the skin as a first line of defense?

Accepted Answer

Presence of cilia

Innate Immunity: The Body’s First and Second Lines of Defense

Study Guide - Practice Questions