Physiology chapter 5

Card Set Information

Physiology chapter 5
2011-07-06 01:35:48

Show Answers:

  1. The Law of mass balance
    Says that if the amount of a substance in the body is to rmain constant, any input must be offset by an equal loss
  2. Clearance
    • Is the rate at which a material is removed from the blood by excreation, metabolism or both
    • ex: Liver kidneys lungs and skin all clear substances from the blood
  3. Chemical disequilibrium
    Most solutes are concentrated in either ine compartment or the other
  4. Electrical disequilibrium
    Cations and anions are not distributed equally between the body compartments
  5. Osmotic equilibrum
    Water moves freely between the cells and the extracellular fluid

    Water always moves from hyposmotic to hyperosmotic
  6. Lipid soluble substances
    can diffuse through the phospholipid layer. Less lipid soluble molecules require the assistance of a membrane protein to cross the membrane
  7. Passive transport
    Does not require the input of energy
  8. Diffusion
    • is the passive movement of molecules down a chemical concentration gradient from an area of higher concentration to lower concentration.
    • Net movement stops when the system reaches an equilibrum but molecular movement continues.
    • Is slow over long distances is directley related to temp and inversley related to molecular size
  9. Simple diffusion
    • passive movment of molecules from and high concentration to a low concentration across the membrane
    • Its directly related to proportional membrane surface, concentration gradiant and permeability and inversley proportional to membrane thickness
  10. Membrane proteins have four functional roles
    • Structual proteins: maintian cell shape and form cell junctions
    • Membrane associated enzymes: Catalyze chemical reactions and help transfer signals across the membrane
    • Receptor proteins: are part of the bodys signaling system
    • Transport proetins: move many molecules into or out of the cell
  11. Channel proteins
    form water filled channles that link the intracellular and extracellular compartments
  12. Facilitated Diffusion
    Protein mediated diffusion. (Help)
  13. Active transport
    • moves molecules against the concentration gradiant and requires an outside sorce of energy
    • Direct: Energy comes from ATP
    • Indirect: Uses potentioal energy stored in the concentration gradiant indirectly driven by ATP
  14. Sodium potassium ATPase
    The most important primary active transporter. 3 Na+ out of cell 2 K+ into cell.
  15. Phagocytosis and Endocytosis
    Large molecules are brought in this way. Materials leave by exocytosis
  16. Osmosis
    The movement of water across the membrane in responce to a concentration gradiant
  17. Osmolarity
    Number of particles per liter in a solution
  18. Tonicity
    Cell volume change when it is placed in a solution
  19. Hypertonic solution
    cells shrink
  20. Hypotonic
    Cells swell
  21. Isotonic
    No change cells are at equalibrium