Endocrine System

• Endocrine SYSTEM - contains hormone-releasing glands
• Endocrine GLANDS - ductless, travels to the bloodstream, has target organs
• The Pituitary gland is divided into two main sections: Anterior Pituitary (front lobe) and the Posterior Pituitary (back lobe).
• Posterior Pituitary - STORES hormones produced by the hypothalamus until needed
• ADH/Antidiuretic Hormone:

  • under POSTERIOR PITUITARY
  • increases WATER REABSORPTION (by kidneys)
  • decreases SWEATING AND URINARY OUTPUT
  • target organ: kidneys
• Oxytocin:

  • under POSTERIOR PITUITARY
  • stimulates uterus contractions during labor
  • releases milk
  • target organ: Uterus, Mammary glands
• Anterior Pituitary - RELEASES hormones that stimulate the release of other hormones (secretions are regulated by releasing hormones from the hypothalamus)
• GH/Growth Hormones

  • under ANTERIOR PITUITARY
  • increases amino acid transport into cells
  • increases PROTEIN SYNTHESIS through INSULIN-LIKE GROWTH FACTORS (IGFs)
  • increases rate of mitosis and use of fats for energy
  • target organ: Bones, muscles, liver
• TSH/Thyroid-stimulating Hormones

  • under ANTERIOR PITUITARY
  • increases secretion of THYROID HORMONES (T3 & T4)
  • target organ: Thyroid gland
• ACTH/Adrenocorticotropic Hormone:

  • under ANTERIOR PITUITARY
  • increases secretion of and adrenal hormone: CORISTOL
  • target organ: Adrenal glands
• Prolactin:

  • under ANTERIOR PITUITARY
  • initiates & maintains MILK PRODUCTION and LACTATION
  • target organ: Mammary glands
• FSH/Follicle-Stimulating Hormone:

  • under ANTERIOR PITUITARY
  • (women) ova development, estrogen secretion
  • (men) sperm development
  • target organ: testes & ovaries
• LH/Luteinizing Hormone:

  • under ANTERIOR PITUITARY
  • (women) ovulation, progesterone secretion
  • (men) testosterone secretion
  • target organ: ovaries and testes
• (T4) Thyroxine and (T3) Triiodothyronine:

  • under THYROID GLAND
  • increases the use of all food types for ENERGY
  • increases PROTEIN SYNTHESIS
  • target organ: muscles & liver
• Calcitonin:

  • under THYROID GLAND
  • decreases CALCIUM absorption
  • decreases BLOOD CALCIUM LEVEL
  • target organ: Bone tissues
• The ADRENAL MEDULLA and ADRENAL CORTEX are the two parts of the ADRENAL GLAND.
• Adrenal medulla - produces hormones for STRESSFUL situations (part of Adrenal Gland)
• Norepinephrine:

  • under ADRENAL MEDULLA
  • stimulates narrowing of BLOOD vessels (a.k.a. Vasoconstriction)
  • increases blood pressure
  • target organ: Blood vessels, Heart
• Epinephrine:

  • under ADRENAL MEDULLA
  • increases heart RATE & FORCE
  • stimulates vasoconstriction and vasodilation (+bronchiole dilation)
  • stimulates GLYcogen to GLUcose conversion by liver
  • increases fats for energy and rate of cell respiration
  • target organ: heart, lungs, liver, brain
• Adrenal cortex - produces certain types of STEROID hormones and small amounts of SEX hormones
• Aldosterone:

  • under ADRENAL CORTEX
  • increases reabsorption of SODIUM and the excretion of POTASSIUM by the kidneys
  • target organ: kidney
• Coristol:

  • under ADRENAL CORTEX
  • increases use of fats & amino acids for energy
  • decrease use of GLUCOSE for conservation (brain)
  • ANTI-INFLAMMATORY EFFECT preventing excessive tissue damage
  • target organ: Liver & muscle
• Pancreas - islets of Langerhans (hormone-producing cells of the pancreas containing ALPHA & BETA cells
• Glucagon:

  • under PANCREAS
  • stimulates the liver to exchange GLYcogen to GLUcose
  • increases use of fats & amino acids for energy
  • target organ: liver
• Insulin:

  • under PANCREAS
  • stimulates the liver to change GLUcose to GLYcogen
  • increases use of glucose by cells to produce energy
  • increases cellular intake of fatty/amino acids
  • target organ: liver
• Pineal gland - secretes a hormone called MELATONIN
• Melatonin:

  • under PINEAL GLAND
  • stimulates onset of SLEEP & increases sleep duration
  • target organ: Brain
• Hyperactive - too much hormones
• Hypoactive - not enough hormones