membrane at rest
DESCRIPTION
Membrane at Rest. Selectively Permeable Channels Ion Concentration Differences Nernst Relationship Ion Pumps. Reflex Loop: Sensory-to-Motor. Water. Phospholipid Bilayer. Membrane is Impermeable. Channels Allow Ions to Pass. Protein Structure. Ion Channel. Potassium Channel. - PowerPoint PPT PresentationTRANSCRIPT
Membrane at Rest
Selectively Permeable Channels
Ion Concentration Differences
Nernst Relationship
Ion Pumps
Reflex Loop: Sensory-to-Motor
Water
Phospholipid Bilayer
Membrane is Impermeable
Channels Allow Ions to Pass
Protein Structure
Ion Channel
Potassium Channel
Potassium Channel Pore
Channels
Ion Concentrations and Nernst Potentials
Nernst Relation
E = 61.54 mV log10 [ion] out/ [ion]in
Lets call it 60 mV
Ion Concentrations and Nernst Potentials
Ion Transporters
Goldman Equation
Vm = 60 log10 Pk[Ko] + PNa[Nao]
Pk[Kin] + PNa[Nain]
Astrocytes Buffer Potassium
• What two functions do proteins in the neural membrane perform to establish and maintain the resting membrane potential?
• ON which side of the membrane are sodium ions more abundant?
• When the membrane is at the potassium equilibrium potential, in which direction (in or out) is there a net movement of potassium ions?
• There is much greater concentration of potassium ions inside than outside the membrane. Why, then is the resting potential negative?
• When the brain is deprived of oxygen, the mitochondria within neurons cease producing ATP. What effect would this have on the membrane potential? Why?
Questions
Next Class
• Chapter 4 The Action Potential