Chapter 13: The Endocrine System

antagonistic

acting in opposition

circadian rhythm

biological cycles that occur at approximately 24-hour intervals

endorphin

a compound produced in the brain and in other body tissues that reduces the sensation of pain

the body’s natural painkiller

gland

a group of specialized cells in the body that produce and secrete a specific substance, such as a hormone

hormone

a substance produced by one tissue or by one group of cells that is carried by the bloodstream to another tissue or organ to affect its psychological functions such as metabolism or growth

receptor

a protein molecule on a cell wall with a unique shape that will allow only one type of molecule, such as a hormone, to attach to it

target cells

cells that have appropriate receptors on their cell walls to allow attachment to a specific molecule

crin/o

secrete

trop/o

affinity to

turn to

respond to a stimulus

aden/o

gland

adren/o

adrenal gland

thyr/o

thyroid gland

andr/o

male

masculine

pseud/o

false

deception