Question 1

Which of the following best describes the function of pattern recognition receptors (PRRs) in innate immunity?

Accepted Answer

They recognize and bind to pathogen-associated molecular patterns (PAMPs) on microbes, initiating immune responses.

Question 2

A patient presents with swollen, painful joints and is diagnosed with rheumatoid arthritis. Which immune system malfunction is most likely responsible for this condition?

Accepted Answer

The immune system is attacking the body's own tissues, mistaking them for foreign invaders.

Question 3

Which of the following is NOT a function of the lymphatic system?

Accepted Answer

Production of digestive enzymes for nutrient absorption.

Question 4

Which of the following best explains why the skin is an effective first line of defense against microbial invasion?

Accepted Answer

It consists of tightly packed epithelial cells impregnated with keratin, making it waterproof and difficult for microbes to penetrate.

Question 5

A laboratory test shows a high neutrophil count in a patient’s blood. What is the most likely explanation for this finding?

Accepted Answer

The patient is experiencing a bacterial infection, as neutrophils react early in the inflammatory response to bacteria.

Question 6

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

Accepted Answer

Chemotaxis, ingestion, phagolysosome formation, destruction, exocytosis

Question 7

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

Accepted Answer

Fever slows bacterial and viral growth, increases white blood cell activity, and speeds recovery time.

Question 8

Which of the following is a characteristic of pathogen-associated molecular patterns (PAMPs)?

Accepted Answer

They are molecules shared by many different kinds of microbes but not present in mammals.

Question 9

A patient with a genetic deficiency in interferon production is likely to experience which of the following?

Accepted Answer

Increased susceptibility to viral infections due to impaired antiviral defenses.

Question 10

Which of the following best explains why the normal microbiota is considered a defense mechanism?

Accepted Answer

It competes with pathogens for nutrients and alters local pH, creating unfavorable environments for pathogens.

Question 11

Which of the following is a correct statement about the complement system?

Accepted Answer

It consists of over 50 blood proteins that work together in a cascade to destroy bacteria and certain viruses.

Question 12

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

Accepted Answer

Lysozyme in tears and saliva that hydrolyzes peptidoglycan in bacterial cell walls.

Question 13

A patient with a severe burn loses much of their skin barrier. Which of the following is the most likely consequence?

Accepted Answer

Increased risk of infection due to loss of the physical barrier against microbes.

Question 14

Which of the following best describes the process of diapedesis?

Accepted Answer

The movement of white blood cells from the bloodstream into tissues by squeezing through endothelial cells.

Question 15

Which of the following is a benefit of edema during inflammation?

Accepted Answer

It dilutes toxic substances and allows clot formation to trap microbes.

Question 16

Which of the following is a correct match between a cytokine and its function?

Accepted Answer

Interleukin-1 (IL-1): Produced by macrophages and involved in fever induction.

Question 17

Which of the following is a correct statement about the spleen?

Accepted Answer

It serves as a filter for blood, removing worn-out red blood cells and pathogens.

Question 18

Which of the following is a correct description of the role of Toll-like receptors (TLRs)?

Accepted Answer

They are a type of PRR that recognize PAMPs and initiate a cascade of events leading to an immune response.

Question 19

A patient with a deficiency in complement proteins would most likely experience which of the following?

Accepted Answer

Increased susceptibility to bacterial infections due to impaired lysis of pathogens.

Host Defenses I: Overview and Innate Immunity (Chapter 15 Study Notes)

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