Section 1 Board Style Questions Flashcards
A 15-year old boy has a history of recurrent bacterial infections. At 18 months, he had pneumonia caused by Streptococcus pneumoniae. When he was 3 years old, he had meningococcal meningitis followed by bacteria sinusitis caused by Haemophilus influenzae type b. A defect in which one of the cells is most likely?
T cells Plasma cells Macrophages Natural killer cells Neutrophils
A 15-year old boy has a history of recurrent bacterial infections. At 18 months, he had pneumonia caused by Streptococcus pneumoniae. When he was 3 years old, he had meningococcal meningitis followed by bacteria sinusitis caused by Haemophilus influenzae type b. A defect in which one of the cells is most likely? T cells Plasma cells Macrophages Natural killer cells Neutrophils
Defense against “pyogenic”extracellular bacteria with polysaccharide capsules depends mostly on antibody-mediated (humoral) immunity. Plasma cells are derived from B cells an secrete antibodies that can opsonize encapsulated bacteria and target them for destruction by immune cells. Three common encapsulated bacteria are Streptococcus pneumoniae, Hemophilus influenzae and Neisseria meningitides.
Your patient has a child who has no detectable T or B cells. This immunodeficiency is probably the result of a defect in:
The thymus
The lymph node
T cell-B cell interaction
Stem cells originating in the bone marrow
Your patient has a child who has no detectable T or B cells. This immunodeficiency is probably the result of a defect in:
The thymus
The lymph node
T cell-B cell interaction
Stem cells originating in the bone marrow
B and T cells arise from a common lineage of pluripotential stem cells in the bone marrow. If there is an absolute deficiency of both T and B cells, this suggests a deficit of these pluripotential stem cells in a primary lymphoid organ (the bone marrow).
C3a and C5a are primarily responsible for:
Gram negative bacterial lysis
Increased vascular permeability
Opsonization and phagocytosis of IgE coated bacteria
Formation of the membrane attack complex
C3a and C5a are primarily responsible for:
Gram negative bacterial lysis
Increased vascular permeability
Opsonization and phagocytosis of IgE coated bacteria
Formation of the membrane attack complex
C3a and C5a are responsible for increased vascular permeability and chemotaxis. C3b is an opsonin. And C5b-C9 are the MAC – responsible for Gram negative bacterial lysis.
