tests of cerebral lateralization. 1  sodium amytal test: anesthetize one hemisphere and check for language function. 2  dichotic listening test: report more digits heard by dominant half. 3  functional brain imaging: fMRI or PET used to see which half is active when performing a language test.
one of a large group of low-molecular-weight proteins secreted by various cell types and involved in cell-to-cell communication, coordinating antibody and T cell immune interactions, and amplifying immune reactivity. Cytokines include colony-stimulating factors, interferons, interleukins, and lymphokines, which are secreted by lymphocytes.
T cells are activated when a particular phagocyte known as an antigen-presenting cell (APC) displays the antigen to which the T cell is specific. This blended cell (mostly human but displaying an antigen to the T cell) is a trigger for the various elements of the specific immune response. A subtype of T cell known as a T helper cell performs a number of roles. T helper cells release chemicals to.