An exoskeleton (external skeleton) is common in arthropods like insects, spiders, and crustaceans.

Part of the brainstem, the medulla is the connection between the brain and the spinal cord. It controls involuntary actions like breathing, swallowing, and heartbeat.

The respiratory system manages respiration which is the process by which blood cells absorb oxygen and eliminate carbon dioxide.

Food is mixed with gastric acid and pepsin in the stomach to help break down protein.

A warm front is the boundary between warm and cool (or cold) air when the warm air is replacing the cold air. Warm air at the surface pushes above the cool air mass creating clouds and storms.