Question 1

Which of the following best distinguishes innate immunity from adaptive immunity?

Accepted Answer

Innate immunity provides a rapid, non-specific response to pathogens, while adaptive immunity is slower and highly specific to particular antigens.

Question 2

Toll-like receptors (TLRs) play a crucial role in innate immunity by:

Accepted Answer

Recognizing pathogen-associated molecular patterns (PAMPs) and activating immune cell responses.

Question 3

Which of the following is a chemical factor involved in innate immunity provided by the skin?

Accepted Answer

The low pH of sebum secreted by sebaceous glands.

Question 4

Which of the following is NOT a physical factor in innate immunity?

Accepted Answer

Lysozyme in saliva

Question 5

Normal microbiota contribute to innate immunity by:

Accepted Answer

Competing with pathogens for nutrients and producing substances harmful to pathogens.

Question 6

Which of the following white blood cells is correctly matched with its primary function?

Accepted Answer

Eosinophils – defense against parasitic worms

Question 7

Which of the following best describes the difference between the lymphatic and blood circulatory systems?

Accepted Answer

The lymphatic system returns interstitial fluid to the bloodstream and is involved in immune surveillance, while the blood circulatory system transports oxygen, nutrients, and waste products.

Question 8

Phagocytosis involves several steps. Which of the following correctly lists the stages in order?

Accepted Answer

Chemotaxis, adherence, ingestion, digestion

Question 9

During inflammation, which of the following mediators is primarily responsible for increasing blood vessel permeability?

Accepted Answer

Kinins

Question 10

A patient presents with a high fever following a bacterial infection. Which of the following best explains the physiological cause of fever in this scenario?

Accepted Answer

Pyrogens such as interleukin-1 (IL-1) are released, causing the hypothalamic set point to increase.

Question 11

Which of the following is NOT a major component of the complement system?

Accepted Answer

Immunoglobulin G (IgG)

Question 12

Which pathway of complement activation is triggered by antigen-antibody complexes?

Accepted Answer

Classical pathway

Question 13

Which of the following is a consequence of complement activation?

Accepted Answer

Formation of the membrane attack complex (MAC), leading to cell lysis

Question 14

Interferons are best described as:

Accepted Answer

Proteins produced by virus-infected cells that inhibit viral replication in neighboring cells.

Question 15

Which of the following correctly compares the actions of IFN-α and IFN-β with IFN-γ?

Accepted Answer

IFN-α and IFN-β primarily induce antiviral states in cells, while IFN-γ activates macrophages and enhances phagocytosis.

Question 16

Iron-binding proteins contribute to innate immunity by:

Accepted Answer

Sequestering iron, making it unavailable for microbial growth.

Question 17

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

Accepted Answer

Disrupting microbial membranes and inhibiting cell wall synthesis.

Question 18

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

Accepted Answer

Increased susceptibility to recurrent bacterial infections due to impaired opsonization and MAC formation.

Question 19

During a bacterial infection, which sequence best describes the migration of phagocytes to the site of infection?

Accepted Answer

Margination, diapedesis, chemotaxis

Question 20

A wound becomes red, swollen, and warm after injury. Which of the following best explains the role of vasodilation in this inflammatory response?

Accepted Answer

Vasodilation increases blood flow to the area, delivering immune cells and nutrients necessary for tissue repair.

Innate Immunity: Nonspecific Defenses of the Host – Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards