* The nervous system controls homeostasis by sending electrical signals to muscles and glands. For example, when the body temperature gets too high, the nervous system sends signals to the sweat glands to produce sweat, which cools the body down.

* The endocrine system controls homeostasis by releasing hormones into the bloodstream. Hormones are chemical messengers that travel throughout the body and affect the activity of cells. For example, when the blood sugar level gets too low, the endocrine system releases the hormone glucagon, which causes the liver to release glucose into the bloodstream.