NROSCI 1011 U2

Multipolar neurons

Most common type of neuron, have multiple dendrites and one axon. Always send signal from dendrite → soma → axon terminal

Bipolar neurons

Found in retinal circuitry, have one dendrite and one axon. Always send signal from dendrite → axon terminal

Psuedo-unipolar neurons

Common in the peripheral nervous system, have a single axon with peripheral and central branches but no dendrite. The peripheral tip functions as a dendrite to receive signal and conduct it to axon terminal

Sensory neuron

Can be bipolar or pseudo-unipolar. Receive information from receptors in the PNS and synapse in the CNS (usually spinal cord). AKA afferent neuron

Afferent neuron

A neuron that carries signal from the PNS to the CNS; a sensory neuron

Motor neuron

Multipolar neurons that transmit signals from the CNS to an effector in the PNS (ex. smooth muscle); AKA efferent neuron

Efferent neuron

A neuron that carries signal from the CNS to the PNS; a motor neuron

Interneuron

A (typically) multipolar neuron that is neither sensory nor motor and is located entirely within the CNS

Neuronal circuit

The reflex arc between a sensory neuron and a motor neuron that involves 2 peripheral nerves and sometimes an interneuron

Glial cells

Non-neuronal cells that are found in the nervous system and perform various functions

CNS glial cells

Microglia, ependymal cells, astrocytes, and oligodendrocytes

PNS glial cells

Schwann cells

Microglia

The smallest of glial cells; act as phagocytes for foreign material following brain injury

Ependymal cells

Line cavities of the CNS and form barriers for ventricles

Astrocytes

Regulate ion concentrations of CSF, neurotransmitter concentration, and blood flow (via regulation of the blood-brain barrier using end-feet)

Oligodendrocytes

Form myelin in the CNS by wrapping around multiple axons per oligodendrocyte

Schwann cells

Form myelin in the PNS by wrapping around a small portion of a single axon