$$1.2 \leq \text{pH} \leq 3.0$$

Question 1

Which of the following best describes the role of Toll-like receptors (TLRs) in innate immunity?

Accepted Answer

TLRs in plasma membranes of macrophages and dendritic cells bind to invading microbes, triggering immune responses.

Question 2

A patient with a genetic deficiency in complement protein C3 is most likely to experience which of the following?

Accepted Answer

Increased susceptibility to disease due to impaired cell lysis, inflammation, and opsonization.

Question 3

Which physical factor is primarily responsible for moving microorganisms out of the lower respiratory tract?

Accepted Answer

The ciliary escalator

Question 4

During the early stages of infection, which type of leukocyte predominates?

Accepted Answer

Neutrophils

Question 5

Which chemical factor found in tears, saliva, nasal secretions, and perspiration is responsible for breaking down bacterial cell walls?

Accepted Answer

Lysozyme

Question 6

A patient develops a fever after a bacterial infection. Which of the following molecules is most likely responsible for inducing this fever?

Accepted Answer

Interleukin-1 (IL-1)

Question 7

Which process describes the movement of phagocytes from the bloodstream into tissues at the site of infection?

Accepted Answer

Diapedesis

Question 8

Which of the following is NOT a function of antimicrobial peptides (AMPs)?

Accepted Answer

Activating complement proteins

Question 9

A bacterial pathogen evades destruction by complement by producing a capsule. Which step in the complement cascade is most directly affected?

Accepted Answer

Activation of C3 leading to opsonization

Question 10

Which of the following best explains why normal microbiota can prevent the growth of pathogens?

Accepted Answer

Normal microbiota change the environment, making it less favorable for pathogens.

Question 11

Which equation best represents the pH range of gastric juice that prevents microbial growth in the stomach?

Accepted Answer

$$1.2 \leq 	ext{pH} \leq 3.0$$

Question 12

Which of the following is a correct sequence of events in phagocytosis?

Accepted Answer

Chemotaxis → Adherence → Ingestion → Digestion

Question 13

A patient with a severe burn loses the integrity of their skin. Which line of defense is most compromised?

Accepted Answer

First line of defense (physical and chemical barriers)

Question 14

Which of the following best describes the role of opsonization in the immune response?

Accepted Answer

Opsonization coats microbes with serum proteins, enhancing phagocyte adherence.

Question 15

Which of the following is a characteristic sign of inflammation?

Accepted Answer

Pain, redness, immobility, swelling, and heat (PRISH)

Question 16

Which pathway of complement activation does NOT require antibodies?

Accepted Answer

Alternative pathway

Question 17

Which of the following statements about antimicrobial peptides (AMPs) is TRUE?

Accepted Answer

AMPs inhibit cell wall synthesis and destroy DNA and RNA.

Question 18

Which of the following best describes the function of iron-binding proteins in innate immunity?

Accepted Answer

They transport and store iron, depriving pathogens of available iron.

Question 19

A patient is exposed to a virus. Which interferon is most likely to induce uninfected cells to produce antiviral proteins?

Accepted Answer

IFN-α

Question 20

Which equation best represents the relationship between the number of leukocytes ($$L$$), granulocytes ($$G$$), and agranulocytes ($$A) in $$blood?

Accepted Answer

$$L = G + A$$

Innate Immunity: Nonspecific Defenses of the Host (Chapter 16 Study Notes)

Study Guide - Practice Questions