Page 318 - Clinical Immunology_ Principles and Practice ( PDFDrive )

CHaPTEr 20 Host Defenses at Mucosal Surfaces 298.e1

MULTIPLE-CHOICE QUESTIONS

1. The following are major characteristics of mucosal effector Correct Order:
sites: A. IgA1→IgA2→IgA2→IgA1
A. Essentially all of the T and B cells present are of a memory B. IgA2 →IgA1→IgA1→IgA2
phenotype. C. IgA1→IgA2→IgA1→IgA2
B. Most of the plasma cells are producing polymeric immu- D. IgA2→IgA1→IgA2→IgA1
noglobulin A (pIgA). 3. The existence of a “common mucosal immune” system suggests
+
C. The majority of T cells are CD4 and have characteristics that mucosal tissues are connected. This means that:
either T-helper 1 (Th1)- or Th2-type helper cells. A. Nerves connect distant mucosal sites.
+
D. Significant numbers of functional CD8 cytotoxic T B. Immune cells freely move between mucosal sites.
lymphocytes (CTLs) are present. C. Selected homing receptors and addressins control homing
E. All of the above.
to selected tissues.
2. Two IgA subclasses occur in humans, IgA1 and IgA2. However, D. Homing receptors and addressins play no role in homing
their distribution in mucosal effector sites is remarkably to effectors sites.
different. For example:
_____ predominates in tissues from the waist up, whereas
_____ is prevalent in the lower gastrointestinal (GI) tract. In
this regard, ______ predominates in the upper respiratory
tract and nasal mucosa. On the other hand, ______ predomi-
nates in the lower ileum and colon.