Final: Basic Structure of Neuron & Structural/Functional classifications of Neurons.

Motor Neurons

Compose the efferent division of the nervous system. About half a million in the body. Send impulses to to divisions. Also know as efferent neurons.

Bipolar Neuron

Have a number of fine dendrites that fuse to form a single dendrite. The cell body lies between this dendrite and a single axon. They are relatively rare but play an important role in relaying sensory information. Their axons are not myelinated.

Pseudounipolar Neuron

Have continuous dendritic and axonal processes, and the cell body lies off to one side. In these neurons, the initial segment lies at the base of the dendritic branches, and the rest of the process is structurally and functionally considered an axon.

Multipolar Neuron

Have several dendrites and a single axon that may have one or more branches. Multipolar neurons are the most common type of neuron in the CNS.

Sensory Neurons

Most Sensory Neurons are pseudounipolar with their cell bodies located in the PNS and their function is to deliver messages to the CNS. Also known as Afferent Neurons, there are 3 different kinds ; exteroceptors, proprioceptors and interoceptors.

Synaptic knobs

Rounded areas at the end of axon terminals.

Anaxonic Neuron

Small with no anatomical clues to distinguish dendrites from axons. Only found in the CNS and Special sense organs, their functions are poorly understood.

Axon hillock

The axon hillock is a specialized part of the cell body (or soma) of a neuron that connects to the axon.

Soma

The cell body containing the nucleus, mitochondria, ribosomes, and other organelles and inclusions.

Nucleus

The central structure of the neuron that contains the nucleolus.

Nodes (of Ranvier)

The gaps in myelin sheath.

Myelin Sheaths

The insulating envelop of myelin that surrounds the axon of a neuron. Formed from the cell membrane of Schwann cells.

Nucleoulus

The large structure within the nucleus of the neuron.

Axon

The long slender projection of the nerve cell, conducts neural impulse towards synaptic terminals.

Dendrite(s)

The tentacle like structures protruding from the soma. Stimulated by environmental changes or the activities of other cells.