Blood glucose levels vary widely over the course of a day as periods of food…

Hormones have a wide range of effects and modulate many different body processes. The key…

Hormones mediate changes in target cells by binding to specific hormone receptors. In this way, even…

Figure 18.1.  The process of amphibian metamorphosis, as seen in the tadpole-to-frog stages shown here,…

Audition, or hearing, is important to humans and to other animals for many different interactions.…

A pheromone is a chemical released by an animal that affects the behavior or physiology of animals…

Odorants (odor molecules) enter the nose and dissolve in the olfactory epithelium, the mucosa at the…

Somatosensation is a mixed sensory category and includes all sensation received from the skin and…

Four aspects of sensory information are encoded by sensory systems: the type of stimulus, the…

Figure 17.1.  This shark uses its senses of sight, vibration (lateral-line system), and smell to…