21.3 Short Answer Questions
1) The tonsils located just behind the openings of the pharyngotympanic tubes in the pharynx are the ________ tonsils.
2) The ________ is the site of T cell maturation.
3) Tumorlike lesions of the skin and some internal organs caused by a type of herpesvirus is called ________.
4) ________ flows in one direction, toward the heart.
5) The lumbar and intestinal trunks unite at the ________ of the thoracic duct.
6) ________ are lymphatic structures that collect fat-laden fluids from the intestinal tract.
7) The HIV that causes AIDS infects immune cells that have the surface protein called ________.
8) The ________ prevents premature activation of immature thymic lymphocytes.
9) Congestion of the tonsils with bacteria results in ________.
10) The ________ tonsils are the ones most often infected and removed during a tonsillectomy.
11) The paired ________ drain lymph from the head and neck.
12) The ________ duct drains three-quarters of the body.
13) Lymphocyte ________ results in immune cells that have gained the ability to attack specific antigens.
14) Lymphoid tissues that enclose the central arteries of the spleen are collectively called ________.
15) Aggregated lymphoid nodules and the ________ contain dense concentrations of lymphoid tissue and are associated with the distal structures of the digestive tract.