Lesson 3: Maintenance of the Internal Environment

  1. active transport
    involves the expenditure of extra energy from the cell's own energy reserves and can result in net movement of solute uphill against a concentration gradient
  2. adenosine triphosphate
    in primary active transport, the carrier derives its energy from this
  3. antiport
    one solute may be exchanged for another in a process of exchange
  4. ATPase
    a large family of enzymes
  5. blood plasma
    the fluid component of blood
  6. carriers
    proteins that actually bind individual solute molecules on one side of the membrane and release the solute on the opposite side of the membrane
  7. channels
    barrel-shaped pores that enclose a small water-filled passage through which solutes diffuse as if in free solution
  8. cotransport
    multiple solutes of different types may need to bind to the carrier before all are translocated
  9. diffusion
    the movement of a substance due to the random movement of its individual particles
  10. diffusion coefficient
    a factor that determines the rate of net movement of a substance by diffusion, it is a property that depends on the particle size of the substance and the nature of the medium in which diffusion is occurring
  11. diffusion potential
    the charge separation generated by this process can be measured as an electrical voltage between the two chambers
  12. distance
    a key factor that determines the rate of net movement of a substance by diffusion. Greater distances reduce the rate of net movement.
  13. effectors
    changes the regulated variable in the direction of the setpoint
  14. endocytosis
    process of cellular uptake in which a small region of the plasma membrane is first indented to form a pocket and then is pinched off to form an endocytotic vesicle
  15. endocytotic vesicle
    a packet of plasma membrane containing anything that was within the pocket when it formed
  16. enzymes
    any of a very large class of complex proteinaceous substances (as amylases or pepsin) that are produced by living cells, that are essential to life by acting like catalysts in promoting at the cell temperature usually reversible reactions
  17. equilibrium potential
    the magnitude of the equilibrium potential (E) is directly related to the magnitude of the concentration gradient, since one must balance the other
  18. exchange
    a process in which one solute may be exchanged for another (antiport)
  19. exocytosis
    a process in which intracellular vesicles fuse with the plasma membrane and release their contents to the exterior
  20. exothermic
  21. extracellular compartment
    all of the solution outside cells
  22. extracellular fluid
    all the fluid outside cells, which has two main components; the interstitial fluid and the blood plasma
  23. hypertonic
    a solution that contains higher impermeant solute concentration and causes cells to shrink
  24. hypertonic challenge
    a homeostatic challenge that adds additional impermeant solute to the ECF without changing the total water content of the body will drive movement of water from the intracellular compartment to the extracellular compartment until the osmotic concentrations of both compartments are again equal, but higher than normal
  25. hypotonic
    solution that contains a lower concentration of impermeant solute than normal cytoplasm (and therefore a higher osmotic strength) and causes cells placed in it to swell
  26. hypotonic challenge
    a homeostatic challenge that decreases total extracellular solute will result in osmotic flow of water into the cells until the osmotic concentration of the two compartments becomes equal, but lower than the normal.
  27. interstitial fluid
    fluid that immediately surrounds cells in tissues
  28. intracellular compartment
    compartment, which is surrounded by a water-permeable barrier, that holds all of the cytoplasm of a cell
  29. ions
    atoms or molecules that have an electrical charge
  30. isotonic
    solutions throughout most organs and tissues in which the osmotic concentration of the cytoplasm is approximately 300 mOsmoles/liter
Card Set
Lesson 3: Maintenance of the Internal Environment
anatomy and physiology