Resting Membrane Potential PDF

Resting Membrane Potential Irma Khachidze PhD 1. Plasma Membrane- Structure and Function 2. Why study Membrane Potential (Em)? 3. What is it? Resting potential 4. How does the membrane potential arise? 5. ION CHANNELS 6. The membrane potential can be measured 7. Eq...

Resting Membrane Potential Irma Khachidze PhD 1. Plasma Membrane- Structure and Function 2. Why study Membrane Potential (Em)? 3. What is it? Resting potential 4. How does the membrane potential arise? 5. ION CHANNELS 6. The membrane potential can be measured 7. Equilibrium potential 8. The sodium/potassium pump 2 Nneurons are specialized to respond to physical and chemical stimuli, conduct electrochemical impulses, and release chemical regulators Through these activities, neurons enable the perception of sensory stimuli, learning, memory, and the control of muscles and gland- basis of living system  Peripheral proteins are only partially embedded in one face of the membrane, whereas Integral proteins span the membrane from one side to the other. The fluid-mosaic model of the plasma membrane. Flexible Plasma Membrane-Function Surrounds the cell, gives it form, and separates the cell’s internal structures from the extracellular environment; Controls passage of materials into and out of cell- facilitates entrance and exit materials-  The proteins found in the plasma membrane serve a variety of functions; including structural support, transport of molecules across the membrane, membrane proteins serve as receptors for neurotransmitter chemicals released by nerve fibers at the synapse  THE SPIKE - Hodgkin and Huxley (H&H) – NOBEL 1963) Sir Alan Lloyd Sir Andrew Fielding Hodgkin Huxley The Squid Giant Axon Axial electrode Plasma Membrane-structure The neuron at the resting membrane potential is much more permeable to K than to Na Every cell has a voltage called a The diffusion of K+ and Na+ through these membrane potential. channels leads to a separation of charges across the membrane, producing resting The inside of a cell is negative potential relative to the outside- Lock spring-elasticity At rest a neuron has a polar nature to it’s membrane There is a positive charge outside the cell and a negative charge inside the membrane Na/ K pump actively transports sodium ions back out of the cell and potassium ions back into cell The resting neuron, has a membrane potential close to Ek because its membrane permeable to K. These leakages are countered by the constant activity of Na /K pumps fixed anions In all neurons, the resting potential depends on the ionic gradients that exist across the plasma membrane 1. The the concentrations of each ion on the two sides of the plasma membrane.  2. The permeability of the membrane to each different ion. THE SPIKE - Hodgkin and Huxley (H&H) – NOBEL 1963) Sir Alan Lloyd Sir Andrew Fielding Hodgkin Huxley The Squid Giant Axon Axial electrode