Question 1

Which of the following best describes the role of skin secretions in the first line of defense against pathogens?

Accepted Answer

They make the epidermal surface acidic, which inhibits bacterial growth.

Question 2

A patient presents with a bacterial infection in the respiratory tract. Which surface barrier mechanism is most likely helping to prevent the spread of pathogens deeper into the lungs?

Accepted Answer

Mucus trapping and ciliary movement propelling debris away from the lower respiratory passages

Question 3

Which of the following is NOT a function of inflammation in the innate immune response?

Accepted Answer

Directly produces antibodies against pathogens

Question 4

During phagocytosis, which process enhances the ability of phagocytes to adhere to pathogens?

Accepted Answer

Opsonization

Question 5

Which chemical defense is released by virus-infected cells to warn neighboring cells and inhibit viral replication?

Accepted Answer

Interferons

Question 6

A patient with tuberculosis has granulomas in their lungs. What is the primary function of these granulomas?

Accepted Answer

To wall off and contain the bacteria that are resistant to lysosomal enzymes

Question 7

Which of the following is a cardinal sign of inflammation and its physiological cause?

Accepted Answer

Redness due to increased blood flow

Question 8

Natural killer (NK) cells are part of the innate immune system. Under which circumstance might NK cells target a body cell?

Accepted Answer

When the cell lacks 'self' markers (MHC proteins) on its surface

Question 9

Which of the following best explains the mechanism by which fever is produced during infection?

Accepted Answer

Pyrogens released by leukocytes and macrophages reset the hypothalamic thermostat to a higher temperature

Question 10

Which equation best represents the relationship between the rate of phagocytosis ($R$) and the concentration of opsonins ($O$), assuming a direct proportionality?

Accepted Answer

$R = kO$

Question 11

Which of the following chemical defenses is most directly responsible for amplifying all aspects of the inflammatory response and lysing microorganisms?

Accepted Answer

Complement proteins

Question 12

A patient with a high fever is found to have increased levels of ferritin in their blood. What is the physiological significance of this finding?

Accepted Answer

Ferritin binds iron, making it unavailable to bacteria and inhibiting their growth

Question 13

Which of the following is an example of a molecule that acts as an opsonin?

Accepted Answer

Antibodies

Question 14

Which process allows neutrophils to move out of the bloodstream and into tissues at the site of infection?

Accepted Answer

Diapedesis

Question 15

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

Accepted Answer

Innate defenses respond quickly and non-specifically, while adaptive defenses target specific pathogens and take longer to react.

Question 16

Which of the following is a physiological effect of kinins released during inflammation?

Accepted Answer

Induction of pain and promotion of chemotaxis

Question 17

A patient with chronic hepatitis C is treated with interferon therapy. What is the primary mechanism by which interferons help fight viral infections?

Accepted Answer

They stimulate neighboring cells to produce proteins that block viral replication

Question 18

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

Accepted Answer

It inhibits microbial growth and enhances body repair processes

Question 19

Which of the following is a multi-step process that involves recognition, adherence, ingestion, and digestion of pathogens by immune cells?

Accepted Answer

Phagocytosis

Question 20

Which equation best represents the effect of fever on the rate of enzymatic reactions ($R_e$) in the body, assuming a Q10 coefficient of 2 for every 10°C increase in temperature ($T$)?

Accepted Answer

$R_e = R_0 	imes 2^{(T-37)/10}$

The Immune System: Innate and Adaptive Body Defenses (Part 1) – Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards