21.7: Key Terms

adrenal glands

small, triangular-shaped endocrine glands located on top of each kidney that produce and release a variety of hormones that are essential for regulating several vital functions in the body

adrenal insufficiency

insufficiency of the adrenal glands caused by complete or partial destruction of the adrenal cortex, which prevents the adrenal glands from producing adequate amounts of cortisol and aldosterone; also known as Addison’s disease

alarm reaction

first stage of GAS, in which a response to short-term stress is mediated by the hormones epinephrine and norepinephrine from the adrenal medulla via the SAM pathway; also called the fight-or-flight response

Cheyne-Stokes respirations

respiration characterized by cyclical episodes of hyperventilation and apnea

colloid

viscous fluid that stores the glycoprotein thyroglobulin, the precursor to the thyroid hormones

congenital hypothyroidism

disorder characterized by cognitive deficits, short stature, and sometimes deafness and muteness in children and adults born to mothers who were iodine-deficient during pregnancy

Cushing’s disease

condition characterized by excess production of circulating cortisol; caused by a tumor or adenoma on the pituitary gland

Cushing’s syndrome

condition in which the body makes too much cortisol over a long period of time

diabetes insipidus (DI)

disorder in which water cannot be retained by the kidneys and is lost as urine; caused by chronic underproduction of ADH or a mutation in the ADH receptor; also known as arginine vasopressin deficiency (AVP-D)

diabetes mellitus (DM)

disease characterized by inappropriately high levels of blood glucose

diabetic ketoacidosis (DKA)

serious complication of diabetes characterized by high blood glucose, ketone production, and metabolic acidosis due to insufficient insulin

endocrine signaling

process by which hormones secreted into the extracellular fluid diffuse into the blood or lymph, enabling them to travel great distances throughout the body

endocrine system

network of cells, tissues, and organs that secrete hormones as a primary or secondary function

euvolemia

state of having a normal volume of fluids in the body

exocrine system

network of glands that release their secretions through ducts

exophthalmos

bulging eyes

fluid deprivation test

assessment for diagnosing diabetes insipidus; involves restricting the patient’s fluid intake while monitoring their body weight and urine concentration

gestational diabetes (GDM)

beta cells in the pancreas become unable to compensate for the demands of pregnancy, causing a dysfunction in the production of insulin and a reduced insulin sensitivity resulting in high blood glucose levels

glucagon

hormone released when the body’s blood glucose is too low, triggering the liver to release stored glucose to raise glucose levels

goiter

enlarged thyroid gland

Graves’ disease

hyperthyroid state that results from an autoimmune reaction in which antibodies overstimulate the follicle cells of the thyroid gland

hormone

chemical substance that travels throughout the body in the bloodstream and affects the activity only of its target cells

hormone receptor

protein that receives and responds to messages from a particular type of hormone

humoral stimuli

changes in blood levels of non-hormone chemicals, such as nutrients or ions, which cause the release or inhibition of a hormone to, in turn, maintain homeostasis

hungry bone syndrome

complication that occurs from prolonged hypocalcemia following surgical correction for hyperparathyroidism

hyperglycemia

high blood glucose levels

hyperosmolar hyperglycemic state (HHS)

severe condition associated with extremely high blood glucose and increased plasma osmolality, but without significant ketone production or metabolic acidosis, commonly occurring in type 2 diabetes

hyperparathyroidism

disorder caused by an overproduction of PTH, resulting in excessive calcium reabsorption from bone

hyperthyroidism

overproduction of thyroid hormones, characterized by an increased metabolic rate and consequential weight loss, excess heat production, sweating, and increased heart rate

hypoparathyroidism

disorder characterized by abnormally low blood calcium levels; may be caused by parathyroid hormone deficiency

hypophysectomy

removal of the pituitary gland

hypothyroidism

underproduction of thyroid hormones, characterized by a low metabolic rate, weight gain, cold extremities, constipation, reduced libido, menstrual irregularities, and reduced mental activity

insulin

hormone that helps cells absorb glucose for energy and lowers the body’s blood sugar levels

Kussmaul respirations

rapid, deep breathing at a consistent pace

myxedema coma

severe case of hypothyroidism that causes respiratory depression, hypothermia, and bradycardia

negative feedback loop

process characterized by the inhibition of further secretion of a hormone in response to adequate levels of that hormone

neural stimuli

release hormones in response to neural stimulation

osmotic diuresis

increased urination caused by increased concentration of glucose in the kidneys

parathyroid

gland located on the posterior surface of the thyroid gland

pituitary gland

bean-sized organ suspended from the hypothalamus that produces, stores, and secretes hormones in response to hypothalamic stimulation

polydipsia

extreme thirst

polyuria

excessive urination volume

positive feedback loop

process characterized by the release of additional hormones in response to an original hormone release

stage of exhaustion

third stage of GAS, in which individuals may begin to experience depression, the suppression of their immune response, severe fatigue, or even a fatal heart attack

stage of resistance

second stage of GAS, in which the individual’s body tries to adapt to stress

syndrome of inappropriate antidiuretic hormone release (SIADH)

disorder in which unsuppressed or over-release of ADH prevents the production of urine in the kidneys and impaired water secretion and leads to hypervolemia and hyponatremia

thyroid

butterfly-shaped gland with two lobes that are connected by the isthmus

thyroid storm

medical emergency caused when the thyroid gland releases a large amount of thyroid hormone in a short period of time

type 1 diabetes mellitus (T1DM)

condition where autoimmune disease damages the beta cells of the pancreas so they do not produce insulin; thus, synthetic insulin must be administered by injection or infusion

type 2 diabetes mellitus (T2DM)

condition where cells of the body become resistant to the effects of insulin, so the pancreas increases its production of insulin

vitiligo

patches of skin without pigment