Endocrine System: Introduction
what are the endocrine organs
hypothalamus, thymus, pancreas, overies/testies, kidneys, stomach, heart, skin adipose tissue.
what are the endocrine glands
pituitary, thyroid, parathyroid, adrenal, pineal.
secrete products into interstitial fluid and diffuse into blood
secretes products into ducts or lumen or to the outer surface of the body.
what are hormones
mediator molecules released in one part of the body that regulate activity in other parts of the body
what do local hormones do
act locally on neighboring cell or on the same cell that secreted them without first entering the blood stream.
is the same cell
what is an example of autocrine
histamine released by mast cells stimulates HCl secretion from parietal cells in stomach
what is an example paracrine
IL-2 released from helper T cells stimulates proliferation of helper T cells and activation of cytotoxic T cells
what is circulating hormones
enter interstitial fluid and then the bloodstream
steriod hormones are drived from ____________
what makes the steroid hormone special
chemical groups attached to core of structure.
have four rings attached to them
name some steroid hormones
cortisol, testosterone, estrogen, progesterone, aldosterone
what do thyroid hormones have attached to them
tyrosine ring with attach iodines
what is nitric oxide
a gas, hormones, and neurotransmitter.
peptide and protein hormones are __________
chains of amino acids
peptide and proteins hormones secrete ______________ hormones
hypothalamic releasing and inhibiting hormones
what are biogenic amines
modified amino acids
what are types of peptide and protein hormones
oxytocin, antidiuretic hormone (ADH), human growth hormone (hGH), thyroid stimulating hormone (TSH), adrenocorticotropic hormone (ACTH)
name the catecholamino
NE, epinephrine, dopamine, serotonin, melatonin, histamine
Eicosanoids are what types of hormones
water soluble hormone
where Eicosanoids are drived from
arachidonic acid (20 carbon fatty acids)
prostaglandins and leukotrienes are examples what type of hormones
Eicosanoids are what types of hormones
what are the functions of hormone
helps regulate: extracellular fluid, metabolism, biological clock, contraction of cardiac & smooth muscle, glandular secretion, some immune functions, growth & development, reproduction.
hormones will only affect what type of cells
target cells with specific membrane or intracellular (protein) receptors.
what happens if there is no receptor
there will be no hormone receptor interaction
what happens if a bad receptor
hormone will not going to hormone.
what are the general mechanism of action of hormones
binds to cell surface or receptor inside target cell
how does the cell response to the hormones
synthesis of new molecules
changes in membran permeability
alter rates of reaction
what happens to different target cells when hormones bind to them
they will response differently
what happens to hepatocytes when insulin binds to it
it stimulates glycogen sysnthesis
what happens to adipocytes when insulin binds to it
it stimulates triglyceride synthesis
Hormones binds to same ________ on different cells
what type of hormones are steroids
lipid soluble hormone
the receptors for a steroid hormone are ____________ types of hormones.
steroids work by
changing the level of specific gene expression
lipid soluble proteins need ____________ while in the blood capillary
a hormone without transport protein is called
steroid proteins diffuse into the Iipid bilayer why
because they are lipid so they jeu go through the lipid bilayer
what does the activated receptor-hormones complex do
alters gene expression (take a section of the DNA to make a new protein)
The hormone than produces ______ after it alters the gene expression.
the new formed mRNA goes to the cytosol where it directs formation of ___________
specific proteins on ribosome
what do new proteins do
they alter the cells activity
what do peptide hormone bind to
bind to cell surface receptors
peptide bonds evoke changes in the activity of existing proteins through
what is the second messenger called
what do second messengers do
alter the phosphorylation state of existing proteins
what results when peptide hormones binds to its receptor
it activates G protein
what happens when G protein is activated
it activates adenylate cyclase
what does adenlate cyclase do
converts ATP to cAMP
what serves as the second messengers after peptide hormones
what do cAMP do
activates protein kinase
what does the activates protein kinase do
phosphorylate cellular proteins
phosporlation of cellular proteins is what type of ____________ process.
Do the same hormone use the same second messengers
they may use different second messengers in different target cells
second messenger initiate ____________.
a cascade of biochemical reactions.
first messengers only influence what type of proteins
proteins inside the cells