Final answer:
The endocrine system is a collection of ductless glands that produce hormones. Hormones are chemical messenger molecules that are released into the bloodstream by endocrine glands and travel throughout the body to affect cells with receptors for them. Examples of endocrine glands include the adrenal glands and the thyroid gland.
Step-by-step explanation:
The endocrine system is a collection of ductless glands that produce hormones.
Hormones are chemical messenger molecules that are released into the bloodstream by endocrine glands. They travel throughout the body, affecting any cells that contain receptors for them. Examples of endocrine glands include the adrenal glands and the thyroid gland. These glands secrete hormones that regulate various body processes such as responses to stress and metabolic rates.