Question 1

Which of the following best describes the role of the acid mantle in the immune system?

Accepted Answer

It inhibits bacterial growth on the skin and mucous membranes by maintaining a low pH.

Question 2

A patient with a genetic defect preventing the production of lysozyme would be most susceptible to which type of infection?

Accepted Answer

Bacterial infections in the oral cavity and eyes

Question 3

Which of the following is NOT a function of mucin in the immune system?

Accepted Answer

Directly killing bacteria by enzymatic digestion

Question 4

If the surface barriers are breached by a cut, which line of defense is immediately activated?

Accepted Answer

Innate internal defenses

Question 5

Which of the following chemicals is toxic to bacteria and found in sebum and sweat?

Accepted Answer

Dermcidin

Question 6

Which structural modification in the respiratory tract helps prevent the entry of pathogens?

Accepted Answer

Cilia sweeping mucus toward the mouth

Question 7

Which of the following best explains why the adaptive immune response takes longer to mount than the innate response?

Accepted Answer

It requires activation and proliferation of specific lymphocytes after exposure to an antigen.

Question 8

Which equation best represents the relationship between the rate of pathogen removal ($R$) and the effectiveness of surface barriers ($E$) and internal defenses ($I$)?

Accepted Answer

$R = E + I$

Question 9

A person inhales dust particles. Which sequence correctly describes the immune system's response?

Accepted Answer

Mucus-coated hairs trap particles, cilia sweep mucus to mouth, particles are expelled or swallowed.

Question 10

Which of the following is a chemical barrier produced in response to barrier breach and inflammation, and inhibits microbial growth?

Accepted Answer

Defensins

Question 11

Which of the following statements about the integration of innate and adaptive defenses is correct?

Accepted Answer

Proteins released during innate responses can alert adaptive immune cells to the presence of specific foreign molecules.

Question 12

Which of the following is a general response of the innate internal defenses?

Accepted Answer

Inflammation and activation of antimicrobial proteins

Question 13

Which of the following is NOT a surface barrier?

Accepted Answer

Inflammatory cytokines

Question 14

If a pathogen successfully penetrates the first line of defense, which process is most likely to occur next?

Accepted Answer

Activation of inflammation and phagocytosis

Question 15

Which of the following best describes the difference between innate and adaptive immunity?

Accepted Answer

Innate immunity provides a rapid, nonspecific response; adaptive immunity provides a slower, specific response.

Question 16

Which of the following is a mechanical barrier that lines body tracts and helps prevent pathogen entry?

Accepted Answer

Mucosae

Question 17

Which equation best models the additive effect of multiple surface barriers ($B_1$, $B_2$, $B_3$) on overall protection ($P$)?

Accepted Answer

$P = B_1 + B_2 + B_3$

Question 18

Which of the following is a real-world example of a surface barrier failing, leading to activation of internal defenses?

Accepted Answer

A person gets a paper cut and the area becomes red and swollen.

Question 19

Which of the following is a chemical produced by neutrophils in response to barrier breach and inflammation?

Accepted Answer

Defensins

Question 20

Which of the following best explains why cilia in the upper respiratory tract are important for immune defense?

Accepted Answer

They sweep dust- and bacteria-laden mucus toward the mouth for removal.

The Immune System: Innate and Adaptive Body Defenses

Study Guide - Practice Questions

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