Word Parts and Structural Terms

Combining Forms

acr/o: extremities, height

aden/o: gland

adren/o: adrenal glands

adrenal/o: adrenal glands

calc/i: calcium

cortic/o: cortex, outer layer of a body organ

dips/o: thirst

glyc/o: sugar

endocrin/o: endocrine

kal/i: potassium

natr/o: sodium

parathyroid/o: parathyroid gland

pituitar/o: pituitary gland

thyr/o: thyroid gland

thyroid/o: thyroid gland


eu-: normal, good

hypo-: below, under, deficient

hyper-: above, excessive

para-: around, beside, beyond, abnormal

poly-: many, much

syn-: joined, together

pan-: all, total


-al: pertaining to

-drome: run, running together

-ectomy: excision, cut out

-emia: in the blood

-ia: condition of, abnormal state, diseased state

-ism: state of

-itis: inflammation

-logist: specialist or physician who studies and treats

-logy: study of

-megaly: enlarged, enlargement

-oid: resembling

-oma: tumor

-pathy: disease

-plasia: condition of, formation, development, growth

-tomy: incision, cut into

Structural Terms Built from Word Parts

pituitary gland: 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.

hypothalamus: located superior to the pituitary gland in the brain. The hypothalamus secretes “releasing” hormones that function to stimulate or inhibit the release of pituitary gland hormones.

thyroid gland: largest endocrine gland. It is located anteriorly in the neck below the larynx and comprises bilateral lobes connected by an isthmus. The thyroid gland secretes the hormones triiodothyronine (T3) and thyroxine (T4), which require iodine for their production. Thyroxine is necessary for body cell metabolism.

parathyroid glands: four small bodies embedded in the posterior aspect of the lobes of the thyroid gland. Parathyroid hormone (PTH), the hormone produced by the glands, helps maintain the level of calcium in the blood by its effects on bone and kidneys.

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. Nonendocrine cells found throughout the pancreas produce enzymes that facilitate digestion.

adrenal glands: paired glands, one of which is located superior to each kidney. The outer portion is called the adrenal cortex, and the inner portion is called the adrenal medulla.


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Medical Terminology: An Interactive Approach Copyright © 2022 by LOUIS: The Louisiana Library Network is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.

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