ENDOCRINE SYSTEM Anatomy & Physiology

Endocrine system - Act by means of hormones, synthesized in glands and secreted into blood Hormones- chemical signals that act on target cells work on specific targets!

Types of hormones Amino acid based- water soluble; receptor on membrane Lipid based- lipid soluble; receptor inside of cell

GLANDS True glands- ductless, secrete hormones into circulatory system, thyroid and pituitary Exocrine glands- secrete through a duct to outside surfaces/organs; not part of endocrine system, salivary/mammary/sweat

Circulating vs. local hormones Circulating hormones- travel Local hormones- no traveling, only affect nearby cells

Cell signaling Endocrine: travels to distant cells; need a receptor Paracrine: has local effect on cells nearby Autocrine: act on cell that made it  A cell can be all three!

Transport and removal of hormones Transport of hormones Unbound- water soluble; short duration Bound- hormones attached to binding proteins; have a prolonged effect Removal of hormones Degrading enzymes Kidneys Liver enzyme system

ENDOCRINE DISRUPTORS Foreign molecules that interrupt normal function of a hormone pathway DDT (pesticide) BPA (found in plastic) PCB (industrial chemical)  

“Goldilocks” Principle Hypersecretion- too much Extra!! Extra!! Hyposecretion- too little HYPO is TOO LOW Both lead to an imbalance which can lead to disease/disorder/etc.

Hormone interaction

Let’s check the hormone/gland chart! *or create A new one Crash course: ENDOCRINE system, glands, and hormones The Science of Adrenaline Fight or Flight Response