Answers

Aggregates of lymphocytes are most common in the small intestine (Peyer's patches) and in the vermiform appendix. Are these aggregates encapsulated or unencapsulated? unencapsulated

1. Which lymphatic organs have afferent lymphatic vessels? Lymph nodes
2. How do lymphocytes enter:
   a. lymph nodes - high endothelial venules?
   b. MALT - high endothelial venules?
3. What are the components of the blood thymic barrier? a perivascular connective tissue sheath containing macrophages, a basal lamina, and an epithelioreticular cell sheath
4. Which of the lymphatic organs filters blood? spleen