Posts: 3,675,935
Threads: 734,343
Joined:
Sep 2021
Reputation:
5
Question 1
Which of the following is correct regarding innate immunity?
a) The two principle phagocytes are macrophages and eosinophils.
b) C-reactive protein binds to microbial surfaces and triggers activation of complement.
c) The alternative pathway of complement activation is triggered by antibodies bound to a microbe.
d) The C3b molecule acts as an opsonin.
Question 2
Which of the following is correct regarding humoral immunity?
a) Successful activation of naïve B lymphocytes requires help from CD8+ helper T lympocytes.
b) Activated B lymphocytes enter the germinal centre of lymphoid follicle and undergo class switching and somatic hypermutation.
c) The Fc portion of an antibody is the antigen binding region.
d) Immunoglobulin M is the major immunoglobulin in serum.
Question 3
Which of the following is correct regarding cellular immunity?
a) Developing T cells that bind too strongly or too weakly to self-MHC molecules in the thymus are deleted by apoptosis.
b) CD4+ helper T lymphocytes recognized antigen bound to MHC class I molecules.
c) Full activation of T lymphocytes requires a costimulatory signal via the B7 protein on the T lymphocyte cell surface.
d) The Th2 subset of T helper lymphocytes activates macrophages via the cytokine interferon-g.
Question 4
Which of the following is correct regarding hypersensitivity reactions?
a) Type I hypersensitivity reactions are also known as delayed-type hypersensitivity.
b) Hypersensitivity pneumonitis is due to a combination of type II and type IV hypersensitivity reactions.
c) The dominant mode of injury in systemic lupus erythematosus is a type III hypersensitivity reaction.
d) Anaphylaxis is a severe form of type IV hypersensitivity.
Question 5
Which of the following is correct regarding human immunodeficiency virus (HIV) infection?
a) Inoculation of the virus through contaminated needles is the dominant mode of transmission.
b) Gastrointestinal infection by Mycobacterium avium intracellulare is a common cause of persistent diarrhoea.
c) Meningitis caused by Cryptosporidium is a well recognized infection.
d) Kaposi's sarcoma is related to human papillomavirus infection.
Posts: 3,675,935
Threads: 734,343
Joined:
Sep 2021
Reputation:
5
Which of the following is correct regarding innate immunity?
Your Answer:
d) The C3b molecule acts as an opsonin.
Feedback:
The two principle phagocytes are macrophages and neutrophils. C-reactive protein is an acute phase protein which binds to microbial surfaces and targets them for phagocytosis. The alternative pathway of complement activation is triggered automatically on microbial surfaces which lack complement regulatory proteins in their cell membranes. The C3b molecule is an opsonin, flagging microbes for phagocytosis.
Page reference: 34-6
Question 2
Which of the following is correct regarding humoral immunity?
Your Answer:
b) Activated B lymphocytes enter the germinal centre of lymphoid follicle and undergo class switching and somatic hypermutation.
Feedback:
Successful activation of B lymphocytes requires help from CD4+ helper T lymphocytes. The Fc portion of an antibody mediates the effector functions of the antibody; the Fab portion is the antigen binding region. Immunoglobulin G is the major immunoglobulin in serum.
Page reference: 38-41
Question 3
Which of the following is correct regarding cellular immunity?
Your Answer:
a) Developing T cells that bind too strongly or too weakly to self-MHC molecules in the thymus are deleted by apoptosis.
Feedback:
Developing T cells that bind too strongly or weakly to self-MHC molecules are deleted in the thymus to generate a repertoire of T lymphocytes that are self-recognizing but not self-reactive. CD4+ helper T lymphocytes recognize antigen bound to MHC class II molecules. Full activation of T lymphocytes requires a costimulatory signal via the CD28 molecule on T lymphocytes. The Th1 subset of T helper lymphocytes activates macrophages via the cytokine interferon-g.
Page reference: 41-4
Question 4
Which of the following is correct regarding hypersensitivity reactions?
Your Answer:
c) The dominant mode of injury in systemic lupus erythematosus is a type III hypersensitivity reaction.
Feedback:
Type I hypersensitivity reactions are mediated by cross-linking of IgE on mast cells by environmental allergens. Anaphylaxis is a severe form of type I hypersensitivity. Hypersensitivity pneumonitis is due to a combination of type III and type IV hypersensitivity. The principle mechanism of cell damage in systemic lupus erythematosus is a type III (immune complex-mediated) hypersensitivity reaction.
Page reference: 44-7
Question 5
Which of the following is correct regarding human immunodeficiency virus (HIV) infection?
Your Answer:
b) Gastrointestinal infection by Mycobacterium avium intracellulare is a common cause of persistent diarrhoea.
Feedback:
The dominant mode of transmission of HIV is sexual. Chronic diarrhoea is common in patients with HIV and may be due to a number of infections including Mycobacterium avium intracellulare, Giardia lamblia, and Cryptosporidium. Meningitis caused by the fungus Cryptococcus is a well recognized infection. The vascular neoplasm Kaposi's sarcoma is related to infection with human herpes virus 8.
Page reference: 49-50
