Endocrine System Flashcards
What is the Endocrine System?
Another way to regulate and coordinate animal body functions; works together with the nervous system to maintain homeostasis. The endocrine system works over long term while the nervous system works over short term, both using extensive feedback loops for coordination.
What features does the Endocrine System share with the Nervous System?
Both use chemical messengers to signal effector cells, similar mechanisms of messenger release, and similar mechanisms at effector of cell membrane, and both have similar biochemical diversity (4/5 neurotransmitters, 3 major hormones).
What differences does the Endocrine System have from the Nervous System?
All animals use endocrine signals, chemical signals (hormones) are carried in body fluids, and it provides long-term regulation.
What is a Gland?
An organ/tissue responsible for the synthesis and secretion of cellular products.
What is an Exocrine Secretion?
A secretion of chemicals onto a body surface or into a duct.
What is an Endocrine Secretion?
A secretion of chemicals into body fluids. They do not use ducts, they release directly into body fluids - synthesized in epithelial cells first.
What do Endocrine Regulations include?
Autocrine, paracine, and neuro-endocrine regulations.
What is Autocrine Regulation?
Hormones are released by the cell it was synthesized from, acting on the same cell.
What is Paracine Regulation?
Hormones bind to an adjacent cell/cell in close proximity.
What is Neuro-endocrine Regulation?
Hormones are released, move through the blood stream, and bind to cell.
What organs/tissues have dual endocrine and exocrine functions?
Pancreas, reproductive organs, liver, kidney, stomach, small intestine.
What are Hormones?
Signalling molecules secreted by endocrine cells. Hormones regulate physiology, behaviour, and development.
What are Amines?
Hormones that are small, water-soluble, and derived from tyrosine or tryptophan. Their cell receptor is the plasma membrane (except thyroid hormones), and they use second messengers (not thyroid hormones). Hydrophilic.
What are Proteins/Peptides?
Hormones that are water soluble, with the cell receptor on the plasma membrane, and use second messengers. Hydrophilic.
What are Steroids?
Hormones derived from cholesterol, mostly lipid-soluble. Their cell receptor is the cytosol or nucleus, and they usually stimulate gene transcription. Hydrophobic.
What are Fatty Acids/Derivatives?
Hormones like prostaglandins, juvenile hormone (in insects); act as autocrine and paracrine factors.