BIOL 206 Lecture Notes - Lecture 23: Resting Potential, Axon Terminal, Chemical Synapse
Document Summary
Two types of cell in nervous system: nerve cell (neurons, glial cell (glia) All neurons are excitable they can generate and transmit electric signals: electric signals generated by neurons are known as action potentials, generally, glia do not generate action potentials. Neurons have four basic regions: cell body (cid:272)o(cid:374)tai(cid:374)s the (cid:374)u(cid:272)leus, a(cid:374)d (cid:373)ost of the (cid:272)ell"s orga(cid:374)elles, dendrites extend from cell body, bring information from other neurons or sensory cells to the cell body. All neurons share the mechanisms whereby their plasma membranes generate and conduct action potentials: action potentials can travel at speeds up to 100 m/sec. Chemical synapses possess an action potential arriving at the postsynaptic cell from the presynaptic cell that causes the axon terminal to release chemical messenger molecules called neurotransmitters. The neurotransmitters diffuse across the space and bind to receptors on the plasma membrane of the postsynaptic (target) cell. This binding alters the activity of the postsynaptic neuron.
