Endocrine system

  1. ways for cells to communicate
    • 1. Direct: very fast, but also has a very short range. Ex gap junctions in heart cells)
    • 2. Synaptic: nerves (unit 3)
    • 3) Paracrine: extracellular fluid. Ex histamine
    • 4) Endocrine: bloodstream, trigger responses that may last from a few seconds to a lifetime. Ex oxytocin, testosterone

  2. How Do Animal Hormones Work?
    • Hormones act by binding to receptors on or in target cells
    • Receptors for hormones are found in two general locations on target cells:
    • On the plasma membrane
    • Inside the cell, within the cytoplasm or the nucleus

  3. The major endocrine glands and organs are:
    • The hypothalamus–pituitary complex
    • The thyroid gland
    • The pancreas
    • The sex organs
    • The adrenal glands

  4. The pituitary gland
    is pea-sized gland connected to the hypothalamus by a stalk

  5. The pituitary consists of two distinct parts:
    • The anterior pituitary: a true endocrine gland
    • The posterior pituitary: capillary bed and the endings of neurosecretory cells

  6. Anterior pituitary
    • Growth hormone acts on nearly all the bodys cells by increasing protein synthesis, promoting the use of fats for energy, and regulating carbohydrate metabolism
    • During childhood, growth hormone stimulates bone growth, which influences human height

  7. Posterior pituitary
    • synthesize and release either antidiuretic hormone (ADH) or oxytocin
    • Alcohol inhibits the release of ADH and increases urination, resulting in dehydration
    • Oxytocin may play a role in emotions, including trust and both romantic and maternal love

  8. thyroid gland produces
    • thyroxine and calcitonin
  9. Thyroxine
    • iodine-containing amino acid derivative
    • Stimulates glucose breakdown and elevates the metabolic rate of many body cells

  10. The thyroid and parathyroid glands influence
    • metabolism and calcium levels

  11. Pancreas: islet cells
    • produce one of two peptide hormones: insulin and glucagon
    • Insulin and glucagon work in opposition to regulate carbohydrate and fat metabolism
    • Insulin reduces the blood glucose level
    • Glucagon increases it
  12. sex hirnibes
    • The testes: androgens (testosterone )
    • The ovaries: estrogen and progesterone
    • Puberty: hypothalamus stimulate the anterior pituitary to secrete more luteinizing hormone (LH) and follicle-stimulating hormone (FSH)
    • LH and FSH stimulate target cells in the testes and ovaries to produce higher levels of sex hormones
  13. pineal gland
    • melatonin
    • secreted in a daily rhythm, regulated by light entering the eyes
    • regulate the seasonal reproductive cycles of many animals
    • function in humans is still not known
  14. thymus
    • thymosin (T cells)
  15. kidneys
    • erythropoietin (low oxygen levels); renin (low blood pressure); angiotensin (low blood pressure )
  16. erythropoietin
    kidneys (low oxygen levels)
  17. renin
    • (low blood pressure
    • secreted by kidneys
  18. angiotensin
    • low blood pressure
    • secreted by kidneys
  19. Fat cells
    • leptin
    • tells the body how much fat it has stored and therefore how much to eat
    • stimulating the growth of capillaries and speeding wound healing

Card Set
Endocrine system
Endocrine system