Which of the following indicates that the immune system has achieved versatility?
A) Millions of NK cells are produced to ensure efficient immune surveillance.
B) Lymphocytes, which are sensitive to an antigen, undergo repeated cell divisions.
C) Production of many normal B cells and T cells, which will attack "self" antigens, occurs.
D) Lymphocyte cell divisions produce two cell types: one group, which will attack specific antigens, and another group, which will remain inactive until exposed to the same antigen later.
E) Millions of different lymphocyte populations are produced, each with different antigen receptors.
E) Millions of different lymphocyte populations are produced, each with different antigen receptors.
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Answer the following statement true (T) or false (F)
Name the paired central nervous system nuclei that adjust the pace of respiration
A) dorsal respiratory group and ventral respiratory group B) apneustic centers and pneumotaxic centers C) apneustic centers and dorsal respiratory group D) apneustic centers and ventral respiratory group E) pneumotaxic centers and ventral respiratory group
Postganglionic sympathetic fibers to the abdomen originate from:
a. dorsal root ganglia b. collateral ganglia c. cranial ganglia d. chain ganglia
This figure shows the muscles of facial expression. What muscle does number 3 indicate?
A. Platysma B. Epicranius C. Orbicularis oris D. Orbicularis oculi E. Nasalis