endocrine system

Hormones

Chemicals produced in endocrine glands, secreted into the bloodstream and carried to target organs where they cause specific effects

Protein or protein-like nature

Protein-like hormones attach to proteins on the surface of their target organs causing an immediate response

Steroids

Affect the nucleus of the target cells to manufacture certain proteins - a slower respons

Endocrine glands

Are ductless and secrete hormones directly into the blood

Exocrine glands

Have ducts and secrete enzymes

Feedback

When the level of a hormone in the blood controls the production of another

Feedback

Used to maintain hormone levels within a narrow range and important in maintaining homeostasis