Body system that includes internal organs that secrete hormones.
Steroidal or amino acid-based molecules released to the blood that act as chemical messengers to regulate specific body functions.
Ductless glands that empty their hormonal products directly into the blood.
Group of chemical substances including certain hormones and cholesterol; they are fat soluble and contain little oxygen.
These biologically active lipids (made from arachidonic acid) are released by nearly all cell membranes.
a given hormone influences the activity of only certain tissue cells,
target cells form more receptors in response to rising blood levels of the specific hormones to which they respond, a phenomenon
involves loss of receptors and prevents the target cells from overreacting to persistently high hormone levels.
Some endocrine glands secrete their hormones in direct response to changing blood levels of certain critical ions and nutrients.
nerve fibers stimulate hormone release. The classic example of neural stimuli is sympathetic nervous system stimulation of the adrenal medulla to release catecholamines (norepinephrine and epinephrine) during periods of stress
many endocrine glands release their hormones in response to hormones produced by other endocrine organs,
a structurally simple hormone that communicates information about environmental lighting to various parts of the body
a portion of the brain that contains a number of small nuclei with a variety of functions
Neuroendocrine gland located beneath the brain that serves a variety of functions including regulation of gonads, thyroid, adrenal cortex, lactation, and water balance.
One of the largest of the body's endocrine glands; straddles the anterior trachea.
Small endocrine glands located on the posterior aspect of the thyroid gland.
a lymphoid organ situated in the neck of vertebrates that produces T cells for the immune system. The human thymus becomes much smaller at the approach of puberty.
pyramid-shaped organs perched atop the kidneys
Gland located behind the stomach, between the spleen and the duodenum; produces both endocrine and exocrine secretions.
small, oval organs located in the female's abdominopelvic cavity. Besides producing ova, or eggs, the ovaries produce several hormones, most importantly estrogens and progesterone
located in an extra-abdominal skin pouch called the scrotum, produce sperm and male sex hormones, primarily testosterone