Vocabulary

adrenal gland

endocrine organ located atop each kidney that responds to stress and low blood glucose levels

adrenocorticotropin (ACTH)

pituitary hormone that stimulates the adrenal glands to produce cortisol in response to stress and low blood sugar

aldosterone

adrenal hormone that acts on the kidneys to increase sodium and water retention and blood volume in order to regulate blood pressure

androgen

hormone responsible for the development of male sex organs and the maintenance of secondary male characteristics

calcitonin

decreases the activity of osteoclasts, the cells in bones responsible for the breakdown of bone tissue to release calcium into the blood

catecholamine

class of water-soluble hormone produced by the adrenal medulla in response to stressful situations.

cortisol

hormone produced by the adrenal cortex in response to stress and low blood sugar that increases blood sugar levels and suppresses the inflammatory response

endocrine gland

secretes internal chemical messengers (hormones) that travel through the body to act on target cells

epinephrine

catecholamine hormone produced by the adrenal medulla that acts on alpha, beta-1, beta-2, and beta-3 receptors

follicle cavity

fluid-filled, iodine-rich cavity in the thyroid surrounded by a single layer of follicular cells, in which the hormones T3 and T4 are produced

follicle-stimulating hormone (FSH)

secreted from the anterior pituitary, stimulates the growth of ovarian follicles in women; in men, it acts on testicular Sertoli cells to stimulate sperm production (spermatogenesis)

glucagon

pancreatic hormone that increases blood sugar by triggering glycogen breakdown in the liver

homeostasis

state of equilibrium in a system used to maintain a consistent internal environment in the body

hormone

chemical messenger of the body that is secreted by endocrine glands

hypothalamus

brain structure responsible for maintaining homeostasis. It connects the endocrine and nervous systems.

insulin

pancreatic hormone that decreases blood sugar by increasing the rate of glucose uptake in cells throughout the body

islet of Langerhans

specialized cluster of endocrine cells located along the length of the pancreas that produces the hormones glucagon and insulin

luteinizing hormone (LH)

secreted from the anterior pituitary. In women it triggers ovulation and corpus luteal development; in men it stimulates testicular interstitial cells to produce and secrete testosterone.

melatonin

pineal hormone that regulates circadian rhythms; its production increases in the dark

norepinephrine

catecholamine hormone produced by the adrenal medulla that acts mainly on alpha receptors

oxytocin

pituitary hormone involved in several processes including the stimulation of breast milk production and the stimulation of uterine contractions during childbirth

pancreas

elongated glandular organ of the digestive system that regulates blood glucose levels

parathyroid

gland located behind each lobe of the thyroid that regulates calcium levels

parathyroid hormone (PTH)

stimulates osteoclasts to increase the levels of calcium in the blood

pineal gland

brain structure that controls circadian rhythms, or day-night cycles

pituitary

brain structure that functions in close association with the hypothalamus to regulate other parts of the endocrine system.

thyroid

butterfly-shaped gland located in the front of the neck that regulates the body's metabolism

thyroxine (T4)

thyroid hormone containing four iodine ions that targets cells in the body to increase the metabolic rate

triiodothyronine (T3)

thyroid hormone containing three iodine ions that targets cells in the body to increase the metabolic rate

vasopressin

hormone that is produced by the hypothalamus and released from the posterior pituitary gland that acts on the kidneys and increases the amount of water reabsorbed back into the bloodstream