IX. Glossary
A1C: A lab test used to assess long-term blood glucose levels over three months. The general A1C target level is less than 7%.
Adrenal cortex: A component of the hypothalamic-pituitary-adrenal (HPA) axis that produces the steroid hormones important for the regulation of the stress response, blood pressure and blood volume, nutrient uptake and storage, fluid and electrolyte balance, and inflammation.
Adrenal medulla: Neuroendocrine tissue composed of postganglionic sympathetic nervous system (SNS) neurons that are stimulated by the autonomic nervous system to secrete hormones epinephrine and norepinephrine.
Aldosterone: A mineralocorticoid released by the adrenal cortex that controls fluid and electrolyte balance through the regulation of sodium and potassium.
Antidiuretic hormone (ADH): ADH is released by the posterior pituitary in response to stimuli from osmoreceptors indicating high blood osmolarity. Its effect is to cause increased water reabsorption by the kidneys. As more water is reabsorbed by the kidneys, the greater the amount of water that is returned to the blood, thus causing a decrease in blood osmolarity. ADH is also known as vasopressin because, in very high concentrations, it causes constriction of blood vessels, which increases blood pressure by increasing peripheral resistance.
Basal insulin: Long-acting (insulin glargine or insulin detemir) or intermediate-acting (NPH) insulin.
Basal metabolic rate: The amount of energy used by the body at rest.
Blood osmolarity: The concentration of solutes (such as sodium and glucose) in the blood.
Diabetes insipidus (DI): A disease characterized by underproduction of ADH that causes chronic dehydration.
Endocrine gland: Gland that secretes hormones that target other organs.
Exocrine gland: Gland that secretes digestive enzymes.
General adaptation syndrome (GAS): The pattern in which the body responds in different ways to stress: the alarm reaction (otherwise known as the fight-or-flight response), the stage of resistance, and the stage of exhaustion.
Glycolysis: Stimulated by insulin, the metabolism of glucose for generation of ATP.
Goiter: A visible enlargement of the thyroid gland when there is hyperstimulation of TSH due to deficient levels of T3 and T4 hormones in the bloodstream or an autoimmune reaction in which antibodies overstimulate the follicle cells of the thyroid gland, causing hyperthyroidism.
Hormones: Chemical signals sent by the endocrine organs and transported via the bloodstream throughout the body where they bind to receptors on target cells and induce a characteristic response.
Humoral stimuli: Changes in blood levels of nonhormone chemicals that cause an endocrine gland to release or inhibit a hormone to maintain homeostasis. For example, high blood sugar causes the pancreas to release insulin.
Hyperglycemia: Elevated blood glucose levels.
Hyperparathyroidism: A disorder caused by an overproduction of PTH that results in excessive calcium resorption from bo