Transcript Endocrine System Hormones

Endocrine System
What it is….
• The endocrine system consists of a
group of organs (sometimes referred
to as glands of internal secretion)
whose main function is to produce and
secrete hormones directly into the
bloodstream. Hormones serve as
messengers to coordinate activities
of various parts of the body.
Consists of…
• The major organs of the endocrine
system are the hypothalamus, the
pituitary gland, the thyroid gland, the
parathyroid glands, the islets of the
pancreas, the adrenal glands, the
testes, and the ovaries.
The Glands
Hypothalamus
• It is an area of the brain that
produces the "controlling" hormones
that regulate body processes and the
release of hormones from various
glands.
• Stimulates the anterior pituitary to
release hormones
• Inhibits the posterior pituitary from
releasing hormones..
Anterior Pituitary
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Secretes several major hormones:
TSH (thyroid stimulating hormone)
ACTH (adrenocorticotropic hormone)
FSH (follicle stimulating hormone)
LH (lutenizing hormone)
GH (growth hormone)
Prolactin: (lactogenic hormone)
Posterior Pituitary
ADH: antiduretic hormone,
regulates water reabsorption in
the kidneys..ie.. Decreases urine
output
Oxytocin: during pregnancy to
initiate labor…contractions, and
milk “let down”
Thyroid
Thyroxine: T4
Tri-iodothyronine: T3
Calcitonin
T3 &T4: stimulate cellular
metabolism..speeds up cellular
release of energy from foods
Calcitonin: decreases
concentration of calcium in the
blood..by keeping it in bones
Adrenal Glands
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Adrenal cortex:
Glucocorticoids
Mineralocorticoids
Androgens
Mineralocorticoids
• Increase blood Na+, and decrease body K+
by accelerating kidney reabsorption of Na+
and excretion of K+
Glucocorticoids
• Helps maintain blood glucose levels by
increasing gluconeogenesis..from amino
acids and conversion to glucose of fatty
acids from adipose tissue…
• Plays and essential part in maintaining
blood pressure..make it possible for
epinephrine and norepinephrine to maintain
a normal level of vasoconstriction
Glucocorticoids
• Act with epinephrine and norepinephrine to
produce an antiinnflammatory effect to
bring about normal recovery from
inflammation of various kinds
• Produces antimmunity: antiallergy effect:
brings about a decrease in the # of
lymphocytes and plasma cells and therefore
a decrease in amount of antibodies formed
Glucocorticoids
• Quickly increases when body is thrown into
stressful situations.
Adrenal Medulla
• Norepinephrine
• Epinephrine: adrenalin
• Stress response hormones