Chapter 21: Introduction Flashcards
encased endocrine glands
pituitary thyroid parathyroid adrenal pineal
Other Organs/tissues that CONTAIN endocrine cells
hypothalamus thymus pancreas ovaries/testes Kidneys, Liver, Stomach, Heart, Skin, adipose tissue
Endocrine
secrete products into INTERSTITIAL FLUID
diffuse into blood
DO NOT deliver directly to blood.
Exocrine
secrete products into DUCTS or LUMENS or outer surface of the body (skin)
mediator molecules
release in one part of the body that regulates activity of other parts of the body
Local
Circulating
Local Hormones
act on neighboring or same cells WITHOUT entering the blood stream. Autocrine or paracrine
Paracrine
signal to neighboring cell
Autocrine
signal to the same cell
Examples of Local Hormones
IL-2: released from helper T to stim prolif of helper T and activation of cytotoxic T cells
HISTAMINE: released by mast cells stimulate HCl secretion from parietal cells in stomach
circulating hormones
Enter interstitial fluid and then the bloodstream
Lipid Soluble circulating hormones
bound to transport proteins (to trick blood into thinking its water soluble)
water soluble circulating hormones
free (just go)
Steroid hormones characteristics
derived from cholesterol (4 rings)
chem groups attached to core makes it unique
examples of steroid hormones
cortisol testosterone estrogens progesterone aldosterone
Thyroid hormones characteristics
tyrosine rings with attached iodines
very lipid soluble *to get through cells easilt
Nitric Oxide
hormones and neurotransmitters
GAS!!!!!
Pepties and protein hormones
chains of amino acids
hypothalamic release and inhibit hormones
Peptides and proteins hormones examples
ADH, oxytocin, hGH, TSH, ACTH, insulin
glucagon
EPO
Biogenic amines
modified amino acids
biogenic amines examples
catecholamines: NE, epi, dopamine
Serotonin
melatonin
histamine
Eicosanoids
derived from arachiodinic acid (20 carbon FA)
eicosanoids examples
prostaglandins and leukotrienes
local hormones
functions of hormones
regulate: ECF metabolism biological clock (times) contraction of cardiac and smooth muscle glandular secretion some immune functions growth and development reproduction
second messangers: Water solluble hormones
bind to cell surface receptors and influence production of intracellular second messangers
Hormones and second messangers
hormones may increase or decrease level of second messanger
same hormone can use different second messangers in different target cells. Like Norepi
examples of second messangers
cAMP
calcium ions
cGMP
second messanger action
initiate cascade of biochem reactions, often involving phosphorylation or dephosphorylation inside target cell
hormone receptors
Hormones only affect target cells with the right intracellular protein receptors
Hormones bind to…
either surface receptors or receptors inside cell
Steroid hormone action
receptor is intracellular
changes levels of specific gene expression
example of steroid hormone
cortisol (stress hormones)
attaches to DNA, makes RNA carry a new message
lipid soluble hormones
diffuse through bilayer int cell, binds to receptor inside cell
water soluble receptors
a part of the plasma membrane
cell respond via
synth of new molecs
change in membrane permeability
altered reaction rates
different target cells responding to the same hormone
can respond differently
How insulin affects hepatocytes
stimulates GLYCOGEN synth
how insulin affects adiposcytes
insulin stims TRIGLYCERIDe synth
Peptide Hormone action
bind to cell surface receptors evoke changes in activity of EXISTING proteins SECOND messenger (like cAMP)
peptide hormone and second messangers
change phosphorylation state of EXISTING proteins
hormones never get in cell, they just bind to outside then the cell does stuff
