Question 1

Which of the following best describes the primary function of the acid mantle on the skin?

Accepted Answer

It inhibits the growth of microorganisms by creating an acidic environment.

Question 2

A patient with a genetic deficiency in lysozyme production would be most susceptible to which of the following?

Accepted Answer

Increased risk of bacterial infections due to reduced enzymatic destruction of bacteria in saliva and tears.

Question 3

Which of the following is NOT a function of inflammation?

Accepted Answer

Directly produces antibodies to neutralize pathogens.

Question 4

During the inflammatory response, which event is primarily responsible for the redness and heat observed at the site of injury?

Accepted Answer

Vasodilation causing hyperemia (increased blood flow).

Question 5

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

Accepted Answer

Fever causes the liver and spleen to sequester iron and zinc, which are needed by microorganisms.

Question 6

A patient is exposed to a novel virus. Which of the following innate immune responses is most likely to be activated first?

Accepted Answer

Secretion of interferons by infected cells to warn neighboring cells.

Question 7

Which of the following is a correct sequence of events during phagocytosis by a macrophage?

Accepted Answer

Adherence to pathogen → ingestion → formation of phagosome → fusion with lysosome → digestion

Question 8

Natural killer (NK) cells differ from phagocytes in that NK cells:

Accepted Answer

Induce apoptosis in virus-infected and cancer cells lacking 'self' markers.

Question 9

Which of the following statements about the complement system is TRUE?

Accepted Answer

Activation of complement enhances inflammation and directly destroys bacteria.

Question 10

A cut on the skin allows bacteria to enter the body. Which line of defense is breached, and which is activated next?

Accepted Answer

First line is breached; second line (internal defenses) is activated.

Question 11

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

Accepted Answer

They bind to structures on microbes and trigger immune responses.

Question 12

Which of the following is a direct effect of interferons released by virus-infected cells?

Accepted Answer

They stimulate neighboring cells to produce proteins that block viral replication.

Question 13

A patient with a fever has a body temperature of $$39^\circC. $$Which of the following physiological changes is most likely occurring?

Accepted Answer

Increased metabolic rate and enhanced tissue repair.

Question 14

Which of the following is NOT a surface barrier involved in the first line of defense?

Accepted Answer

Complement proteins in plasma

Question 15

A patient with chronic inflammation is likely to experience which of the following cardinal signs?

Accepted Answer

Redness, heat, swelling, pain, and sometimes impairment of function

Question 16

Which of the following best explains why swelling (edema) occurs during inflammation?

Accepted Answer

Increased capillary permeability allows exudate to leak into tissues.

Question 17

Which of the following is a correct statement about the relationship between innate and adaptive immunity?

Accepted Answer

Innate responses can release proteins that alert adaptive immune cells to foreign molecules.

Question 18

A patient is unable to produce defensins. Which of the following would be the most likely consequence?

Accepted Answer

Reduced ability to inhibit microbial growth on mucous membranes.

Question 19

Which of the following best describes the role of exudate during inflammation?

Accepted Answer

It contains clotting factors and antibodies that help isolate and destroy pathogens.

Question 20

A patient with a mutation in the gene encoding for complement proteins would most likely experience which of the following?

Accepted Answer

Impaired ability to enhance inflammation and destroy bacteria.

Innate Immunity: The First Lines of Defense (Immune System Part 1)

Study Guide - Practice Questions