Glossary
Nuclei - Plural of nucleus.
Nucleus - The core of a cell.
Endocrine System - The system that consists of the endocrine glands and the hormones that they secrete.
Nervous System - The system of nerves and nerve centers in an animal or human, including the brain, spinal cord, nerves, and ganglia.
Circadian Cycle - A circadian rhythm is like the body's clock.