stimuli (singular: stimulus): changes in the environment that can be detected by organisms. receptors: cells or groups of cells that detect stimuli effectors: parts of the body that respond to a stimula muscles and glands are effectors.

coordination: ensuring that the actions of different parts of the body work together.

coordination: ensuring that the actions of different parts of the body work together.

nerve: a group of neurone axons lying together (like an electrical cable containing many wiresthorax: the chest; the part of the body from the neck down to the diaphragm.

bronchus: one of the two tubes that takes air from the trachea into the lungs.

bronchiole: a small tube that takes air from a bronchus to every part of the