Question 1

Which of the following best describes the primary function of the complement system in innate immunity?

Accepted Answer

To act as 'land mines' that are triggered to opsonize pathogens and form the Membrane Attack Complex

Question 2

A patient presents with recurrent infections by encapsulated bacteria such as Streptococcus pneumoniae and Neisseria meningitidis. Which immune compartment is most likely defective?

Accepted Answer

Complement system

Question 3

Which of the following is a key difference between innate and adaptive immunity?

Accepted Answer

Innate immunity responds rapidly and non-specifically, while adaptive immunity is slower and highly specific.

Question 4

If a patient has a defect in phagocyte function, which of the following clinical findings is most likely?

Accepted Answer

Soft tissue abscesses and poor wound healing

Question 5

Which of the following best describes the process of antigen presentation by phagocytes?

Accepted Answer

Phagocytes digest pathogens and present peptide fragments on MHC molecules to T cells.

Question 6

Which immune cell type is primarily responsible for producing antibodies?

Accepted Answer

B cells

Question 7

A patient with recurrent sinopulmonary infections (sinusitis, otitis media, bronchitis) is most likely to have a defect in which immune compartment?

Accepted Answer

B cells and antibody production

Question 8

Which of the following is a major function of CD8+ cytotoxic T cells?

Accepted Answer

Killing cells infected with intracellular pathogens such as viruses

Question 9

What is the most likely outcome if T cells are non-functional in a patient?

Accepted Answer

Increased risk of severe viral and fungal infections

Question 10

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

Accepted Answer

Opsonization is the coating of pathogens by immune molecules to enhance phagocytosis.

Question 11

Which of the following equations best represents the formation of the Membrane Attack Complex (MAC) in the complement cascade?

Accepted Answer

$$C5b + C6 + C7 + C8 + C9 \rightarrow MAC$$

Question 12

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

Accepted Answer

Production of insulin

Question 13

A patient with a deficiency in regulatory T cells is most likely to develop which of the following?

Accepted Answer

Autoimmunity

Question 14

Which of the following best describes the sequence of events in the immune response to a new pathogen?

Accepted Answer

Recognition → Alarm → Inflammation → Recruitment of innate cells → Effector function → Antigen presentation → Lymphocyte activation → Memory formation

Question 15

Which of the following pathogens is most likely to cause severe infections in a patient with a phagocyte defect?

Accepted Answer

Staphylococcus aureus

Question 16

Which of the following best explains why encapsulated bacteria are particularly dangerous in patients with complement deficiencies?

Accepted Answer

Encapsulated bacteria are resistant to phagocytosis unless opsonized by complement proteins.

Question 17

Which of the following is a major role of cytokines and chemokines in the immune response?

Accepted Answer

Recruitment and activation of immune cells at the site of infection

Question 18

Which of the following best describes the function of memory cells in adaptive immunity?

Accepted Answer

They provide a faster and stronger response upon re-exposure to the same pathogen.

Question 19

A patient with severe viral infections and inability to generate effective antibody responses most likely has a defect in which immune compartment?

Accepted Answer

T cells

Immunology Overview: The Human Immune System and Its Components

Study Guide - Practice Questions

Study Guide - Flashcards