Bio 106 Exam 4 Lecture 34

: An evolutionary trend toward the concentration of the sensory equipment at the anterior end of the body

: A fiber composed primarily of the bundles axons of PNS neurons

· A typically long extension, or process, of the neuron that carries nerve impulses away from the cell body toward the target cells.

· : One of usually numerous short, highly branched extensions of a neuron that receive signals from other neurons

The junction where a neuron communicates with another cell across a narrow gap via a neurotransmitter or an electrical coupling.

The diffusion gradient of an ion, which is affected by both the concentration difference of an ion across a membrane

· wrapped around the axon of a neuron, an insulating coat of cell membranes from Schwann cell or oligodendrocytes. It is interrupted by nodes of Ranvier where action potentials are generated.