BIO1100- CHP 13 Endocrine System

endocrine system

regulates the functions of the body to maintain homeostasis, and coordinates communication

endocrine glands

cells, tissues, and organs that makeup the endocrine system

exocrine glands

glands that secrete into ducts or tubes that lead to a body surface

nervous system

releases neurotransmitters into synapses

endocrine system

secretes hormones into bloodstream

hormones

released into extracellular fluid, diffuse into blood

two different types to hormones

steroid and nonsteroid hormones

steroid or steroid-like hormones

lipids containing complex rings of carbon and hydrogen atoms, are all produced from cholesterol

proteins

composed of long chains of amino acids

peptides

composed of short chains of amino acids

glycoproteins

carbohydrates joined to proteins

unregulation

increase in number of receptors on target cells, in response to a decrease in hormone level

downregulation

Decrease in the number of receptors on the target cell, due to an increase in hormone level

steriod and thyroid hormones

poor water-solubility, transported through blood bound to plasma proteins, diffuse through the lipid bilayer of cell membranes,

nonsteriod hormones

cant penetraste the lipid bilayer of cell membranes,

hypothalamus

controls release of anterior pituitary hormones; then pituitary hormones secrete hormones that control activity of other glands

nervous system control

directly stimulates some glands to secrete their hormones

negative feedback

control mechanism in which rising level of a hormone leads to a decrease in hormone secretion

positive feedback

control mechanism in which rising level of a hormone leads to an increase in secretion; used in small number of cases of hormone control, mainly reproductive

pituitary gland

lies at the base of the brain, controlled by brain, part of nervous system,