KEY POINTS

■ The endocrine system is part of the regulatory system of the body and works in conjunction with the nervous system. The nervous system produces an immediate response while the endocrine system produces a slower but longer lasting effect.

■ Endocrine glands secrete hormones which are carried by the blood to specific target organs.

■ Each target organ responds only to a particular hormone or to a group of hormones and is unaffected by other hormones.

■ Hormonal secretion is controlled by different mechanisms, e.g. levels of a chemical in the blood, or by a feedback loop.

■ Each hormone has a specific effect and many interrelate with other hormones to create a complex network which acts to maintain the body in a state of equilibrium.