Endocrine System

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Endocrine System
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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.

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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.

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The Glands
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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..

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Anterior Pituitary

• Secretes several major hormones
• TSH (thyroid stimulating hormone)
• ACTH (adrenocorticotropic hormone)
• FSH (follicle stimulating hormone)
• LH (lutenizing hormone)
• GH (growth hormone)
• Prolactin (lactogenic hormone)

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Posterior Pituitary
ADH antiduretic hormone, regulates water
reabsorption in the kidneys..ie.. Decreases urine
output Oxytocin during pregnancy to initiate
laborcontractions, and milk let down
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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
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Adrenal Glands

• Adrenal cortex
• Glucocorticoids
• Mineralocorticoids
• Androgens

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Mineralocorticoids

• Increase blood Na, and decrease body K by
  accelerating kidney reabsorption of Na and
  excretion of K

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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

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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

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Glucocorticoids

• Quickly increases when body is thrown into
  stressful situations.

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Adrenal Medulla

• Norepinephrine
• Epinephrine adrenalin
• Stress response hormones

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