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the body's slow chemical communication system (as opposed to the nervous system); a set of glands that secrete hormones into the bloodstream


a chemical substance secreted by an endocrine gland effects distant parts of the body

endocrine gland

any of the glands of the endocrine system that secrete hormones directly into the bloodstream

hormone receptor

the part of a cell that a hormone binds to exert its effect; if a cell does not have a receptor for a hormone that hormone can not affect it


term for hormones that act on same cells that secrete them


hormones that affect only neighboring cells, really don't use blood vessels to circulate through the whole body


chemical used by a neuron to transmit an impulse across a synapse to another cell (some also have functions as hormones for example epinephrine a.k.a. adrenaline)


a hormone that is released by a neuron (e.g., norepinephrine or vasopressin)


a substance that is a precursor to a hormone, usually modified into the hormone's final form in the endoplasmic reticulum


a substance that is a precursor to a prohormone, has minimal effect as a hormone itself

carrier protein

bind to and carry hormones; required for steroids and thyroid hormones to travel in the blood

releasing hormone

hormone secreted by the hypothalmus that regulates the release of other hormones from the anterior pituitary

tropic hormone

hormone secreted by the pituitary gland that stimulates the production of another hormone; also known as a stimulating hormone ( e.g., thyroid-stimulating hormone)

amino acid

basic building blocks of protein molecules


a molecule that is made up of amino acids and that is needed to build and repair body structures and to regulate processes in the body; many hormones are proteins


chemical made of 4 carbon rings; all steroids are made by modifying cholesterol


macromolecule made mainly from carbon and hydrogen atoms; includes fats, oils, and cell membranes; will NOT mix with water


circulatory fluid; aqueous (likes water, dislikes lipids); hormones must travel through blood to be circulated throughout the entire body


having an affinity for water; readily absorbing or dissolving in water; implies lipophobic


repelling, tending not to combine with, or incapable of dissolving in water (or other aqueous solutions, like blood); implies lipophilic


having an affinity for lipids; readily absorbing or dissolving in oil; able to pass directly through the cell membrane without a special channel or transport mechanism; implies hydrophobic


repelling, tending not to combine with, or incapable of dissolving in lipids; not able to cross the cell membrane without a transport protein; implies hydrophilic

monoamine hormone

a hormone that is a single modified amino acid; often they're also neurotransmitters and they're small enough to pass through the blood brain barrier

peptide hormone

a hormone that is a chain of amino acids, if longer than 20 amino acids or so often called a "polypeptide hormone", if longer than 200 amino acids often called a "protein hormone", really just one class of hormones


lipid molecule with four carbon rings that functions as a hormone

thyroid hormone

any of several closely related compounds that are produced by the thyroid gland and are active metabolically; they contain iodine


lipid derived from arachidonic acid; function as short range messengers (paracrine) in the regulation of various physiological processes


the maintenance of stable internal conditions despite changes in the surroundings, i.e. glucose, calcium, & sodium concentrations, water volume, temperature, etc,


the maintenance of body temperature within a range that enables cells to function efficiently


the organic processes (in a cell or organism) that are necessary for life (i.e. digestion, growth/building cells, elimination of waste, burning/storing fat, etc.)

negative feedback

the most common control mechanism in the endocrine system; the product or response shuts off or reduces the level of the original stimulus (i.e. a high level of a hormone will signal the body to no longer produce that hormone)

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