Flashcards in Chapter 37 Endocrine System Deck (29):
secrete hormones into bloodstream (without a duct)
amines: tyrosine + tryptophan
protein: most hormones
glycoproteins: include LH+FSH
steroids: lipids derived from cholesterol, less soluble in water, non polar. Pass thru plasma membrane to interact with receptors in cytoplasm or nucleus.
No travel in blood
molecules that are produced within one tissue but regulate a different tissue of the same organ (prostaglandins, cytokines, nitric oxide, and growth factors)
chemicals released into environment
molecules that bind the block agonist,
widely used as drugs
lipophilic hormones (water hating)
hormones include steroid hormones (derived from cholesterol) and the thyroid hormones (tyrosine+iodine)
circulate blood bound to transport proteins
can pass through plasma membrane to interact with receptors in the cyplasm or nucleus. These receptors regulate gene transcription.
peptide, protein, amine hormones
react with receptors on the surface of the target cell which then causes second messengers to activate previously inactive enzymes.
-anterior pituitary (adeno)
shaped like bow tie
just below Adam's apple in front of neck
TRH/TSH stimulate thyroid to make thyroid hormones
secretes: thyroid hormones
calcitonin (peptide hormone)
lowering its levels in the blood
low production of thyroxine: reduced metabolism and overweight
high production of thyroxine
high metabolism and weight loss
four small glands attached to the thyroid
produce parathyroid hormone (PTH)
-Stimulates osteoclasts to dissolve calcium phosphate crystals in the bone matrix and release Ca2+ into blood
-Stimulates the kidneys to reabsorb Ca2+ from the urine
above each kidney
medulla: inner portion
secretes epinephrine + norepinephrine
help body prepare for extreme efforts.
cortex: outer portion
secrete steroid hormones:
mineralocorticoids regulate mineral balance by stimulating the kidneys to absorb Na+ and excrete K+
next to stomach
govern blood glucose levels through 2 hormones with a antagonist functions.
Insulin and Glucagon
islets of langerhans
scattered clusters of cells throughout pancreas
secreted by beta cella of islets
stimulates cellular uptake of blood glucose and its storage as glycogen in the liver and muscle cells or as fat in fat cells.
-Secreted by alpha (a) cells of the islets
-Promotes the hydrolysis of glycogen in the liver and fat in adipose tissue
cells with specific receptor proteins for both neurotransmitters and or hormones; tissue usually responds to # of hormones
hormone enhances responsiveness of target cell to 2nd hormone
How do hormones interact with each other?
Anabolic steroid abuse causes testosterone receptors to be downregulated leading to desensitization also you stop producing your endogenous steroids due to negative feedback.
What is the role of the hypothalamus?
Produce ADH and Oxitocin (released in the pituitary) and other releasing hormones.
a portion of the brain base that regulates autonomic functions and secretes hormones, most of which regulate secretory activity of the pituitary gland
molecule that can act as both a neurotransmitter and a hormone
mediate the function of the cells in which they are synthesized
Which of the following is likely NOT to be a mechanism for controlling hormone levels in the blood?
Modify the structure of the hormone at its point of production so it no longer binds its receptor.