Endocrine system Flashcards
Exocrine glands
secrete products through ducts into body cavities or directly onto body surfaces
endocrine glands
secrete products into interstitial fluid where it enters the blood.
Circulating hormones
pass into blood and act on distant cells
paracrine secretions
restricted to the interstitial fluid and affect only nearby cells
autocrine secretions
affect only the secreting cell itself
How are circulating hormones inactivated and or removed from the body?
inactivated by the liver and excreted by the kidneys
Why do hormones only affect certain organs?
hormones only affect specific target cells that have receptors to recognize it
What hormones are steroids?
Cortisol, aldosterone, estrogen, testosterone
Can steroid hormones be taken orally?
yes. They aren’t broken down and are fat soluble.
How are amino acid hormones usually administered?
subcutaneously
Prostaglandins
affect wide variety of tissue. Increase bp, uterine contractions, blood clotting, pain, inflammation.
leukotrines
affect white blood cells. mediate inflammation and some allergic rxn’s
What are 3 ways hormones are regulated?
- tropic hormones stimulate other glands to secrete their hormones. 2. respond directly to changes in the internal environment. 3. nervous system stimulates glands directly.
What protects the pituitary gland?
sphenoid bone
Describe the structure of the pituitary gland
master gland located under the hypophysis. 75% anterior, 25% posterior. The hypothalamus is where the hormones are actually made, but the infundibulum connects the two together.