Endocrine System
Function Maintain Homeostasis (Balance) Communicates and coordinates physiological responses
Hormones Chemical messengers Tropic (Trophic) Hormones Stimulate physiological responses in other cells Target Cells Tropic (Trophic) Hormones Hormone whose target is another endocrine gland.
Hormone Production and Distribution Endocrine Glands Gland: an organ specialized to produce secretions Distribution Relies on blood circulatory system How does this compare to nervous system?
Endocrine Glands Hypothalamus Pituitary Thyroid Parathyroid Pancreas Adrenal Gonads Ovaries, Testes
Hypothalamus Location- Base of brain case Functions- Regulation of Primitive or Basal activities such as sex drive and water balance
Pituitary gland Location- Sphenoid bone of the skull Anterior Lobe Produces Six hormones that Regulate Reproduction, Growth, Activity of the Thyroid Gland Posterior Lobe No hormone production only storage of hypothalamic hormones
Thyroid Largest endocrine gland Location- Wrapped around anterior and lateral sides of Trachea, just below Larynx Hormone- Thyroid Hormone Function- Increases Metabolic Rate
Adrenal Glands Location- 2 glands one superior to each Kidney.
Adrenal Glands (Fight or Flight Response) Stress and immune supression Sex steroids- sex hormones
Pancreas Location- Inferior and posterior to Stomach Secretion of Insulin- converts glucose to glycogen Function- Glucose Regulation
Gonads Male- Testes Female- Ovary Secrete Androgens such as Testosterone Female- Ovary Secrete Estrogen and Progesterone
Pineal Gland Attached to upper part of thalamus Secretes hormone Melatonin Response to light conditions. Acts upon “biological clock” or Circadian Rhythms
Thymus Located posterior to the sternum, between the lungs Secretes Thymosin, affects white blood cells and immunity
Disorders Hypothyroidism (Creatinism) Children: mental retardation, development abnormalities Adults: lethargy, obesity Hyperthyroidism (Graves’ Disease) Weight loss, sweating, nervousness, sleeplessness Goiter -----a hypertrophy of the thyroid gland resulting from iodine deficiency
Disorders Pituitary Dwarfism- Insufficient secretion of Growth Hormone Gigantism- Over-secretion of Growth Hormone
Disorders Diabetes Mellitus- Disruption of Metabolism due to lack of insulin or lack of response to insulin. Symptoms- Excessive Urine, Intense Thirst, and Ravenous Hunger Type I- (Juvenile of Insulin Dependant) Destruction of Insulin Producing Cells Type II- (Adult or Noninsulin Dependant) Target cells resistant to Insulin