Biomed Mod. 14 obj. 1-5

  1. For the purpose of regulating ________, the body is continually receiving interpreting and responding to stimuli. The two main system the of the body that are responsible for this are the _________ and the __________ systems.
    homeostasis, nervous, endocrine
  2. Through the use of mediator molecules, homeostatic mechanisms are strictly controlled.  In the endocrine system these molecules are called __________.
  3. Hormone
    • a mediator molecule secreted from one part of the body that circulates via the body fluids to cells in another part of the body.
    • they are secreted into the interstitial fluid, then typically to the bloodstream gaining access the the entire body.
  4. "Target Cells"
    • A specific cell that responds to the hormone due to the presence of peripheral or intracellular receptors.
    • They are the specific targets of hormones, hence the name. 
  5. The Endocrine system
    • consists of the pituitary, thyroid, parathyroid, adrenal and pineal glands
    • There are other organs and tissues that secrete hormones but they are not exclusively endocrine glands: Hypothalamus, thymus, pancreas, ovaries, testes, kidneys, stomach, liver, small intestine, skin,heart, and placenta
  6. The study of endocrine glands and hormones is called ______________.
  7. The endocrine system is made up of _______ and _______ endocrine organs that, together with the _________ _______ coordinate vital functions in an effort to maintain _________.
    primary, secondary, nervous system, homeostasis.
  8. __________ function to regulate the chemical composition and ________ of the blood, metabolism and energy balance, contraction of smooth and cardiac muscle fibers, glandular secretion, growth and development, reproduction, sleep-wake cycles, and some _______ functions. 
    Hormones, volume, immune
  9. True or False 
    Hormones are not very powerful molecules

    • hormones are very powerful 
    • Their not present in large amounts but their effects are quite dramatic
  10. What are the endocrine systems functions?
    • Control of composition and volume of internal environment
    • Regulate metabolism and energy balance
    • contraction of smooth and cardiac muscle fibers
    • Influence glandular secretions
    • Regulation of sleep-wake cycles
    • Emergency control during physical and mental stress (trauma, starvation, hemorrhage, etc.)
    • Integration of growth and development
    • Reproductive control
  11. True or False
    Molecules can be both neurotransmitters and hormones; it just depends on how they are used.
  12. What is the difference between Nervous and Endocrine systems?
    • Nervous
    •   -Nurotransmitters
    •   -local chemical release across a synapse 
    •   -targets: muscle cells glands and other neurons
    •   -Onset of action: milliseconds
    •   -Acton duration: milliseconds

    • Endocrine
    •   -Hormones
    •   -Responses are usually distant rom the site of release
    •   -Targets: cells throughout the body(any cell)
    •   -Onset of action: seconds to hours to days
    •   -Action duration: generally longer
  13. ___________ are released from neurons to act locally in response to a nerve impulse. They bind to _________ in a post synaptic membrane near the sight of ________.  
    Neurotransmitters, receptors, release
  14. ____________ can be delivered to ______ throughout the body, and binds to receptors in or on the _______ cell.
    Hormones, cells, target
  15. Hormone receptors
    • They are simply cellular proteins
    • like other proteins they can be synthesized, broken down, and synthesized again.
    • Target cells can dictate the number of receptors available to bind hormone.
    •   -Up-regulation: increased responsiveness by increasing receptor numbers
    •   -Down-regulation: Decreased responsiveness by decreasing receptor numbers
  16. Circulating hormones
    Hormones secreted into the interstitial fluid and then into the bloodstream
  17. paracrines
    Hormones secreted into the interstitial fluid that act on neighboring cells 
  18. Autocrines
    Hormones secreted into interstitial fluid that act on the same cell that secreted it.
  19. What types of hormones are Lipid-soluble hormones?
    • Steroid hormones
    • thyroid hormones
    • Nitric Oxide
  20. What types of hormones are Water-soluble hormones?
    • Amine hormones
    • Peptide and Protein hormones
    • Eicosanoid Hormones
  21. True ore False
    Lipid-Soluble hormones can diffuse into a cell and bind directly to intracellular receptors.

    a substance can more easily move into a cell if it is: small, neutrally-charged, or lipid-soluble
  22. Water-soluble hormones must...
    stimulate a cellular change by binding to membrane receptors and initiating a change in the cell indirectly.
  23. Chemical Classes of Hormones:
    • Water-soluble hormones freely circulate in the bloodstream.
    • they cant pass through the cell membrane
    • Examples are:
    •   -Amines
    •   -peptides and proteins
    •   -Eicosanoids
  24. Chemical Classes of Hormones:
    • Most of the available lipid-soluble hormone is carried in the blood by transport proteins.
    • They can freely diffuse through the cell membrane.
    • Examples are:
    •   -steroid hormones
    •   -thyroid hormones
    •   -Nitric Oxide (gas)
  25. True or False 
    Solubility dictates how hormones will be carried in the blood.

    The blood is 55% plasma, and the plasma is 92% water

    In this water soluble environment, water-soluble hormones can circulate as "free" hormones; they aren't attach to any other molecules.
  26. In the blood, lipid-soluble hormones must be bound to _____ ______. By binding to these proteins, the _____ solubility of these hormones is increased.
    transport proteins, water

    These also keep the smaller lipid-soluble hormones from getting filtered into the kidney and lost in the urine.
  27. True or false
    Where most of the water-soluble hormones are free in the blood, only 0.1-10% of lipid-soluble hormones are free.
  28. True or false 
    Whatever the nervous system does there is usually a corollary response by the endocrine system. 
Card Set
Biomed Mod. 14 obj. 1-5
Biomed Mod.14 obj.1-5