MedTerms Chapter 16: Key Terms and Definitions for the Endocrine System

pituitary gland or hypophysis cerebri

approximately the size of a pea and located at the base of the brain. The pituitary is divided into two lobes. It is often referred to as the master gland because it produces hormones that stimulate the function of other endocrine glands

anterior lobe or adenohypophysis

produces and secretes the following hormones

growth hormone (GH)

regulates the growth of the body

adenocorticotropic hormone (ACTH)

stimulates the adrenal cortex

thyroid-stimulating hormone (TSH)

stimulates thyroid gland

gonadotropic hormone

affect the male and female reproductive systems

follicle-stimulating hormone (FSH), luteinizing hormone (LH)

regulate development, growth, and function of the ovaries and testes

Prolactin Releasing Hormone (PRH), lactogenic hormone

promotes development of glandular tissue during pregnancy and produces milk after birth of an infant

posterior lobe or neurohypophysis

stores and releases antidiuretic hormone and oxytocin

Antiduretic hormone (ADH)

stimulates the kidney to reabsorb water

oxytocin

stimulates uterine contractions during labor and postpartum

hypothalamus

located superior to the pituitary gland in the brain; secretes "releasing" hormones that function to stimulate or inhibit the release of pituitary gland hormones

thyroid gland

largest endocrine gland; located anteriorly in the neck below the larynx and comprises bilateral lobes connected by an isthmus; secretes triiodothyronine (T3) and thyroxine (T4)

parathyroid glands

four small bodies embedded in the posterior aspect of the lobes of the thyroid gland

islets of Langerhans

clusters of endocrine tissue found throughout the pancreas, made up of different cell types that secrete various hormones, including insulin and glucagon. Non-endocrine cells found throughout the pancreas produce enzymes that facilitate digestion

adrenal glands or suprarenals

paired glands, one of which is located above each kidney; the outer portion is called the adrenal cortex, and the inner portion is called the adrenal medulla

cortisol

secreted from the adrenal cortex, aids the body during stress by increasing glucose levels

aldosterone

secreted by the adrenal cortex. Electrolytes (mineral salts) that are necessary for normal body function are regulated by this hormone.

Epinephrine (adrenaline) and norepinephrine (noradrenaline)

secreted by the adrenal medulla; help the body to deal with stress by increasing the blood pressure, heartbeat, and respirations

aden/o

gland (CF)

adren/o, adrenal/o

adrenal glands (CF)

cortic/o

cortex (the outer layer of a body organ) (CF)

endocrin/o

endocrine (CF)

parathyroid/o

parathyroid glands (CF)

pituitar/o

pituitary gland (CF)

thyroid/o, thyr/o

thyroid gland (CF)

acr/o

extremities, height (CF)

calc/i

Calcium (Cf)

dips/o

thirst (CF)

kal/i

potassium (CF)

natr/o

sodium (combining form)

-drome

run, running (suffix)

acromegaly

enlargement of the extremities

adenitis

inflammation of a gland

adenomegaly

enlargement of a gland

adenosis

abnormal condition of a gland

adrenalitis

inflammation of the adrenal glands

adrenomegaly

enlargement (of one or both) of the adrenal glands

hypercalcemia

excessive calcium in the blood

hyperglycemia

excessive sugar in the blood

hyperkalemia

excessive potassium in the blood

hyperpituitarism

state of excessive pituitary gland activity (characterized by excessive secretion of pituitary hormones)

hyperthyroidism

state of excessive thyroid gland activity (characterized by excessive secretion of thyroid hormones). Signs and symptoms include weight loss, irritability, and heat intolerance.

hypocalcemia

deficient calcium in the blood

hypoglycemia

deficient sugar in the blood

hypokalemia

deficient potassium in the blood

hyponatremia

deficient sodium in the blood

hypopituitarism

state of deficient pituitary gland activity (characterized by decreased secretion of one or more of the pituitary hormones, which can affect the function of the target endocrine gland; for example, hypothyroidism can result from decreased secretion of thyroid-stimulating hormone by the pituitary gland)

hypothyroidism

state of deficient thyroid gland activity (characterized by decreased secretion of thyroid hormones. Signs and symptoms include fatigue, weight gain, and cold intolerance.)

panhypopituitarism

state of total deficient pituitary gland activity (characterized by decreased secretion of all the pituitary hormones; this is a more serious condition than hypopituitarism in that it affects the function of all the other endocrine glands)

parathyroidoma

tumor of a parathyroid gland

thyroiditis

inflammation of the thyroid gland

acidosis

condition brought about by an abnormal accumulation of acid products of metabolism such as seen in uncontrolled diabetes mellitus

Addison disease

chronic syndrome resulting from a deficiency in the hormonal secretion of the adrenal cortex

congenital hypothyroidism

condition caused by congenital absence or atrophy of the thyroid gland

Cushing syndrome

group of signs and symptoms produced by excess cortisol from the adrenal cortex

diabetes insipidus (DI)

result of decreased secretion of antidiuretic hormone by the posterior lobe of the pituitary gland

diabetes mellitus (DM)

chronic disease involving a disorder of carbohydrate metabolism caused by under-activity of the islets of Langerhans and characterized by elevated blood sugar (hyperglycemia). DM can cause chronic renal disease, retinopathy, and neuropathy. In extreme cases the patient may develop ketosis, acidosis, and finally coma.

gigantism

condition brought about by hypersecretion of growth hormone by the pituitary gland before puberty

goiter

enlargement of the thyroid gland

Graves disease

disorder of the thyroid gland characterized by the presence of hyperthyroidism, causing the production of more thyroid hormone than the body needs, goiter, and exophthalmos

ketosis

condition resulting from uncontrolled diabetes mellitus, in which the body has an abnormal concentration of ketone bodies resulting from excessive fat metabolism

metabolic syndrome

group of signs and symptoms including insulin resistance, obesity characterized by excessive fat around the waist and abdomen, hypertension, hyperglycemia, elevated triglycerides, and low levels of the "good" cholesterol HDL

myxedema

condition resulting from a deficiency of the thyroid hormone thyroxine; severe form of hypothyroidism in an adult

pheochromocytoma

tumor of the adrenal medulla, which is usually non-malignant and characterized by hypertension, headaches, palpitations, diaphoresis, chest pain, and abdominal pain

tetany

condition affecting nerves causing muscle spasms as a result of low amounts of calcium in the blood caused by a deficiency of the parathyroid hormone

thyrotoxicosis

condition caused by excessive thyroid hormones

adenectomy

excision of a gland

adrenalectomy

excision of (one or both) adrenal glands

parathyroidectomy

excision of (one or more) parathyroid glands

thyroidectomy

excision of the thyroid gland

thyroidotomy

incision of the thyroid gland

thyroparathyroidectomy

excision of the thyroid and parathyroid glands

radioactive iodine uptake (RAIU)

nuclear medicine scan that measures thyroid function. Radioactive iodine is given to the patient orally, after which its uptake into the thyroid gland is measured.

thyroid scan

nuclear medicine test that shows the size, shape, and function of the thyroid gland

thyroid sonography

ultrasound test of the thyroid gland used to indicate whether a thyroid nodule is likely benign or possibly malignant; also used to monitor and evaluate structure

fasting blood sugar (FBS)

blood test to determine the amount of glucose (sugar) in the blood after fasting for 8-10 hours. Elevation may indicate diabetes mellitus.

glycosylated hemoglobin (HbA1C)

blood test used to diagnose diabetes and monitor its treatment by measuring the amount of glucose bound to hemoglobin in the blood

thyroid-stimulating hormone level (TSH)

blood test that measures the amount of thyroid-stimulating hormone in the blood; used to diagnose hypothyroidism and to monitor patients on thyroid replacement therapy

thyroxine level (T4)

blood test that gives the direct measurement of the amount of thyroxine in the patient's blood. A greater-than-normal amount indicates hyperthyroidism; a less-than-normal amount indicates hypothyroidism

adrenocorticohyperplasia

excessive development of the adrenal cortex

adrenopathy

disease of the adrenal gland

cortical

pertaining to the cortex

corticoid

resembling the cortex

endocrinologist

physician who studies and treats diseases of the endocrine system

endocrinology

study of the endocrine system

endocrinopathy

any disease of the endocrine system

euglycemia

normal (level of) sugar in the blood (within normal range)

euthyroid

normal thyroid function

glycemia

sugar in the blood

polydipsia

abnormal state of much thirst

syndrome

run together (signs and symptoms occurring together that are characteristic of a specific disorder)

exophthalmos

abnormal protrusion of the eyeball

hormone

chemical substance secreted by an endocrine gland that is carried in the blood to a target tissue

isthmus

narrow strip of tissue connecting two larger parts in the body, such as the isthmus that connects the two lobes of the thyroid gland

metabolism

sum total of all the chemical processes that take place in a living organism