{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

BIO2A03-2011-L21 - Biology2A032009 Lecture21 Recall (EN)...

Info icon This preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
Biology 2A03 -2009 Lecture 21
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Recall: Equilibrium potential (E N ) via the Nernst Equation E N  = “A hypothetical value for the membrane potential at which the electrical  driving force is equal and opposite to the chemical driving force producing an  electrochemical driving force of zero.” If E N  = E M  for an ion then  no electrochemical driving force   acting on it to move  in or out of the cell. If E N    E there will be a driving force for that ion in or out of the cell  depending on the  direction and size of the force . (E N ) for Na + : = 61 log [145 mM]    =      +60 mV               [15 mM] For example  Na requires large positive outward directed electrical force (that is far  from E M ) to counteract a large  inward concentration gradient . So Na has a large  driving force for inward movement.
Image of page 2
Fig  8.10, pg  225 We ak S tim ulus S tro ng  S tim ulus Inhibitory, K + Cl - G.P. is “graded” in proportion to the strength of the stimulus Increased G Na +   Increased G K + or G Cl -
Image of page 3

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
G.P’s at synapses on dendrites or soma are  Post-Synaptic Potentials threshold threshold At e xc itato ry s ynaps e s , the  ne uro - trans m itte r g e ne rally o pe ns  bo th  Na +  &  K +  c hanne ls  ==> inc re as e d G Na+  &  inc re as e d G K+ ==> ne t de po larizatio n “Exc itato ry Po s t-S ynaptic  Po te ntial
Image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern