Ch 17 endocrine pt 1 Flashcards
What are hormones?
Released into the blood and transported throughout the body
What are ligands?
Chemical messengers
Hormones bind to what?
To target cells receptors
Functions of the endocrine system
Regulating development, growth, metabolism, maintaining homeostasis of blood volume and concentrations
What are the endocrine organs?
Pituitary, pineal, thyroid, parathyroid, and adrenal glands
What is a hormonal stimulation?
Releases its hormone when other one bind to it
What is a humoral stimulation?
Releases hormone when a change in the blood occurs
What is nervous stimulation?
Talks to certain tissues to release hormone
Steroids are what?
Lipid-soluble molecules
What are biogenic amines?
Modified amino acids and water soluble except TH.
What are proteins?
Water-soluble chains of amino acids and lots of hormones
What is autocrine stimulation?
Communicate with same cells
What is paracrine stimulation?
Communicate with neighboring cells
What are prostaglandins?
Stimulate pain and inflammatory responses
What are eicosanoids?
A 20-carbon chain formed by a fatty acid.
Lipid-soluble hormones use what?
Carrier molecules
What is a bound hormone?
Bound to a carrier
What is unbound hormone?
Able to exit blood and bind to target cell receptors
What is a half-life in a hormone?
Time necessary to reduce a hormones concentration to half of its original level
What are the results of a hormone-response element of DNA.
Results in a mRNA and translates to a protein
What is the first messenger?
Hormones and binds to receptors
What is activated by the binding of a hormone to a receptor?
Hormone-receptor complex
What does G protein activation split into?
Adenylate cyclase or phospholipase C
What does the activated enzyme catalyze form?
Second messenger
What is a second messenger?
A chemical that modifies cellular activity
What do enzymes do?
Speed up reactions
