Here's why:

* Hormones: The endocrine system is made up of glands that produce and secrete hormones. Hormones are chemical messengers that travel through the bloodstream to target cells and tissues.

* Wide-reaching effects: Hormones regulate a vast array of bodily functions, including:

* Growth and development

* Metabolism (how your body uses energy)

* Mood

* Sleep

* Reproduction

* Heart rate and blood pressure

* Digestion

* Slow and sustained: Compared to the nervous system, which uses electrical impulses, the endocrine system works more slowly but has longer-lasting effects.

Examples of endocrine glands and their hormones:

* Pancreas: Insulin and glucagon (regulate blood sugar)

* Thyroid: Thyroid hormones (regulate metabolism)

* Adrenal glands: Adrenaline and cortisol (stress response)

* Ovaries (female): Estrogen and progesterone (reproductive hormones)

* Testes (male): Testosterone (reproductive hormone)

While the nervous system also plays a role in regulating some chemical activity, it's the endocrine system that primarily governs the chemical environment of the body through hormones.