dendrites cell body myelin axon dendrites conduct electrical

dendrites cell body myelin axon

dendrites: conduct electrical information in the direction of the cell body axons: conduct electrical information away from the cell body Perkins & Kent (1991)

Synapse: A tiny space between the axon of one fiber and the dendrites of another. Neurotransmitter chemicals that are released into the synapse stimulate the adjacent fiber to fire (depolarize). Figure 4 -25. The dendrites of one neuron synapsing with the axon of an adjacent neuron. Reprinted from Denes and Pinson, The Speech Chain, 1993, W. H. Freeman & Co.

Axon hillock: Action potentials originate here and propagate along the length of the axon.

What causes a neuron to fire? (The word fire here means generate a spike potential (an electrical pulse) that travels along the length of the nerve fiber – more very soon. Neurons are stimulated to fire when neurotransmitter chemicals are dumped into the synaptic space that separates the axon of one neuron from the dendrites of an adjacent neuron. (Neurons can also be stimulated to fire when an experimenter uses an electrode to deliver an electrical stimulus to an neuron).

Action potential Nerve propagation https: //www. youtube. com/watch? v=W 2 h. Ht_PXe 5 o

Action Potential resting potential (~-70 m. V)

Better Picture of an Action Potential (This one moves. ) Notice that this figure shows a voltage swing from -70 to +30.