REAL ES 5 Lecture Notes - Lecture 19: Lipid Bilayer, Threshold Potential, Phospholipid
Document Summary
Along the membrane the potential is stable (-60mv). Excitatory and inhibitory inputs in the dendrites will cause changes in resting potential: graded potentials. These can be depolarization (excitatory) or hyperpolarization (inhibitory). When the graded potentials spread along the membrane, the size gets smaller. When the summation of graded potentials at the trigger zone (initiation of axon) is larger than threshold value, an action potential will get started. The total size of an action potential may vary between neurons, but often stays the same for one neuron. Graded potentials have a wide range in durations based on the durations of their inputs. The action potentials of any particular neuron will be the same every time. Larger-diameter axons conduct action potentials faster than small-diameter axons. Myelinated axons conduct action potentials faster than non-myelinated axons (salutatory conduction) At this moment the charge becomes very positive.
