system Made up of the pituitary gland, thyroid
gland, parathyroid glands, the adrenal gland, the isles of Langerhans in the
pancreas, the thymus gland, the pineal gland, and the gonads -- testes in the
male and ovaries in the female. Certain secretions of the stomach and small
intestine are also hormones and thus part of the endocrine system. Through their
secretions the endocrine glands regulate growth, rate of metabolism, response to
stress, blood pressure, muscle contraction, digestion, immune responses, and the
development and functioning of the reproductive system. Hormones exert their
influence by becoming involved with the genetic machinery of cells and by
affecting the metabolic activities of cells working through the cellular
respiration pathways.
