Endocrine System

endocrine system

a collection of glands and groups of cells thats secrete hormones that regulate growth,development, and homeostsis

hormones

chemical "messengers" of the endocrine system that are released into the blood

protein hormones

class of hormones that cannot pass through the cell membrane; less likely to be stored in the body

steroid hormone

class of hormones that can pass through the cell membrane; can be stored in the body

prostaglandins

local hormones that do not enter the bloodstream

positive feedback

Process that amplifies a small change (Reinforce change)

negative feedback

a response that opposes the original stimulus

one messenger model

mechanism of hormone action used by steroid hormones which bring their message directly into the cell

two messenger model

mechanism of hormone action used by protein hormones; attach to cell membrane receptors which activate enzymes in the cell to produce the desired effect

hypersecretion

excessive hormone production by an endocrine gland

hyposecretion

deficient hormone production by an endocrine gland

pituitary gland

the master gland of the endocrine system

growth hormone

hormone secreted by anterior pituitary gland that stimulates growth of bones

luteinizing hormone

A protein hormone secreted by the anterior pituitary that stimulates ovulation in females and androgen production in males.

Prolactin

Peptide hormone released by anterior pituitary which promotes lactation.

follicle stimulating hormone

secreted in increasing amounts during puberty, by the anterior pituitary gland, to stimulate development of reproductive cell follicles

adrenocorticotropic hormone

A peptide hormone released from the anterior pituitary, it stimulates the production and secretion of steroid hormones by the adrenal cortex.

oxytocin

A hormone produced by the hypothalamus and released from the posterior pituitary. It induces contractions of the uterine muscles during labor.

antidiuretic hormone

hormone secreted by the posterior pituitary gland which aids in water reabsorption by the kidney

hypothalamus

part of the brain which links the endocine and nervous system, and controls the pituitary gland.

acromegaly

Hypersecretion of the GH in adults which causes an overgrowth of bones in the hands, feet, and face

thyroid gland

gland found in neck that regulates rate of metabolism; produces thyroxine

calcitonin

Produced by the thyroid gland and decreases the blood calcium levels by stimulating calcium deposit in the bones. The antagonist of the parathyroid hormone.

parahormone

secreted by parathyroid glands and controls calcium and phosphate metabolism

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

osteoporosis

a condition in which the body's bones become weak and break easily; may be caused by hypersecretion of parahormone

adrenal gland

one of a pair of ductless glands, located above the kidneys, consisting of a cortex, which produces steroidal hormones, and a medulla, which produces epinephrine and norepinephrine.

cortex

outer part of kidney which produces corticosteroids; helps body deal with longtern stress

medulla

inner part of kidney which produces epineprine and norepinephrine

cortisol

secreted from the adrenal cortex, aids the body during stress by regulating glucose, carbohydrates, and fat levels

aldosterone

a corticosteroid hormone that is secreted by the cortex of the adrenal gland, regulates mineral balance in blood and controls fluid volumes

Cushing syndrome

excessive production of cortisol by adrenal cortex with symptoms of abnormal fat deposits and wasting away of muscle

pancreas

located partially behind the stomach in the abdomen, and it functions as both an endocrine and exocrine gland. It produces digestive enzymes as well as insulin and glucagon

insulin

a hormone secreted by the beta cells of the Islets of Langerhans of the pancreas responsible for regulating the metabolism of glucose

glucagon

hormone secreted by alpha cells of the pancreas; raises blood glucose levels

diabetes

a condition in which the pancreas fails to produce enough insulin or the body's cells cannot use it properly, characterized by excessive thirst, weight loss/gain, frequent urination.

estrogen

a general term for female steroid sex hormones that are secreted by the ovary and responsible for typical female sexual characteristics

progesterone

A hormone produced by the ovaries which acts with estrogen to bring about the menstral cycle.

testosterone

The male sex hormone produced by the testes which promotes the maturation of the reproductive system accessory structures, and development of the male secondary sex characteristics.

pineal gland

A small mass of tissue near the center of the brain; it secretes the hormone melatonin.

melatonin

Hormone secreted by the pineal gland, used to regulate sleep patterns.

Thymus gland

Gland located near the heart; it aids in the body's defence against infection by making antibodies