Communication between cells is required to coordinate their diverse
activities. Some cells secrete substances that spread only to nearby cells.
Others secrete hormones, molecules that are carried in the bloodstream
to widely distributed cells that have special receptor sites to which they
attach. Along nerve cells, electrical impulses carry information much more
rapidly than is possible by diffusion or blood flow. Some drugs mimic or
block the molecules involved in transmitting nerve or hormone signals and
therefore disturb normal operations of the brain and body.
NSES Content Standard C
Life Science: Regulation and behavior Grades 5-8, page 157 Behavior is one kind of response an organism can make to an internal or environmental stimulus. A behavioral response requires coordination and communication at many levels, including cells, organ systems, and whole organisms. Behavioral response is a set of actions determined in part by heredity and in part from experience. NSES Content Standard C
|