In this deck, we'll explore the endocrine system, the body's second major control system. You'll learn how it uses chemical messengers called hormones to regulate processes over a longer period. We will compare this to the fast-acting nervous system, identify the main endocrine glands, and then look in detail at how the body controls its temperature, a process known as thermoregulation.

The endocrine system is made up of glands that release chemicals directly into the bloodstream. These chemicals are called hormones. A hormone is a chemical messenger that travels in the blood to a target organ, where it produces an effect. A gland that produces and releases hormones is called an endocrine gland.

It's important to compare the endocrine system with the nervous system. The nervous system uses electrical impulses that travel along nerves. Its effects are very fast but don't last long. Think of it like sending an instant message. The endocrine system uses hormones that travel in the blood. Its effects are much slower to start but they last for a longer time. This is more like sending a letter in the post.