NEUROSCI 101 Lecture Notes - Lecture 3: Axon Hillock, Sodium-Potassium Alloy, Chemical Synapse
17 May 2016
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Document Summary
Epsps are smaller in the dendrites than in the axon and receive the impulse that comes from the axon hillock. Dendrites also don"t have voltage-gated na/k channels to allow ion flow. At the axon hillock, graded potentials such as epsp/ipsps are being summed up. Na+ wants to pass through the cell membrane because of the principle of electrostatic attraction (opposite charges attract) to make the inside of the cell less negative. In giant squid axon, action potentials are faster than graded potentials. Myelination speeds action potentials but doesn"t make action potentials faster than graded potentials. A +3 mv charge is administered to a giant squid axon. The voltage reading would decrement as it moves away from the site of stimulation. This charge is considered a graded potential because it hasn"t reached threshold (minimum requirement for +20 mv) yet. (types of neurotransmitters, types of receptors/receptor binding, packaging, enzyme deactivation discussed in paper notes)
