| A | B |
|---|
| Endocrine System | Consist of endocrine glands that secrete hormones, which regulate a wide range of activities in humans |
| Hormones | Are secreted by glands and diffuse directly into the bloodstream |
| Hypothalamus | It controls the release of hormones by the pituitary gland |
| Hypothalamus | Considered to be a major link between the nervous system and the endocrine system |
| Pituitary Gland | Called the “master gland” because it controls the activities of other glands |
| Pituitary Gland | Secretes three major hormones: GH, TSH, and FSH |
| Growth Hormone (GH) | This hormone controls the growth of the body by stimulating the elongation of bones |
| Thyroid Stimulating Hormone (TSH) | Stimulates the thyroid gland to produce its hormone thyroxin |
| Follicle Stimulating Hormone (FSH) | Stimulates the activities of the ovaries and testes |
| Thyroid Gland | Located in the neck below the larynx and in front of the trachea |
| Thyroid Gland | This gland secretes thyroxin which contains iodine |
| Thyroxin | Regulates the rate of metabolism in the body and is essential for normal physical and mental development |
| Goiter | Lack of iodine in the diet will lead to lack of thyroxin secretion. This produces enlargement of the thyroid gland and is called |
| Thyroid Stimulating Hormone (TSH) | Secretion of thyroxin is regulated by |
| Parathyroid Gland | Are tiny oval glands embedded in the walls of the thyroid gland that secretes parathormone |
| Parathormone | Controls calcium metabolism |
| Adrenal Gland | Located on the top of each kidney |
| Adrenal Cortex | Regulate water balance and blood pressure and stimulates the conversion of fat and protein into glucose |
| Adrenal Medulla | Secretes adrenalin |
| Adrenalin | Increases the blood sugar level and accelerates the heart and breathing rate |
| Pancreas | Consists of small clusters or “islands” of hormone-secreting cells called the Islets of Langerhans |
| The Islet of Langerhans | Secrete insulin and glucagon |
| Insulin | Facilitates the entrance of glucose into the cells |
| Glycogen | Insulin lowers blood sugar levels by promoting |
| Glucagon | Stimulates the release of sugar from the liver and into the blood |
| Diabetes | When the Islets of Langerhans fail to produce enough insulin |
| Testes | Secrete testosterone which influences the development of the male secondary sex characteristics |
| Ovaries | Secrete estrogen which influences the development of secondary sex characteristics |
| Negative Feedback | Operates on the principle that the level of one hormone in the blood stimulates or inhibits the production of another hormone |
| Feedback mechanism | Occurs when the level of one substance influences the level of another substance or activity of another organ |
| Dynamic equilibrium | Feedback mechanisms have evolved in living things as a mechanism by which they maintain |
| Dynamic equilibrium | Another name for homeostasis |
