BIOL 216- chapter 5- the neuron

Neuron

A specialized cell that carries electrical signals within the nervous system.

CNS

Central Nervous System, which includes the brain and spinal cord.

PNS

Peripheral Nervous System, composed of afferent (sensory) neurons and efferent (motor) neurons.

Interneurons

Neurons that process information and formulate responses.

Afferent Neurons

Sensory neurons that transmit sensory information from receptors to the CNS.

Efferent Neurons

Neurons that carry signals from the CNS to muscles and glands to initiate responses.

Axon Hillock

The area where action potentials are initiated; has a high concentration of voltage-gated sodium channels.

Dorsal Root

The part of the spinal nerve that contains afferent neurons, carrying information towards the CNS.

Ventral Root

The part of the spinal nerve that contains efferent neurons, carrying information away from the CNS.

Resting Membrane Potential

The membrane potential of a neuron at rest, approximately -70 mV, due to ion distribution.

Goldman Equation

Predicts membrane potential considering multiple ion permeabilities.

Ligand-gated Channels

Channels found at synapses that open in response to neurotransmitter binding.

Action Potential

A sudden and brief change in membrane potential that allows a neuron to conduct an electrical impulse.

Refractory Period

The time after an action potential during which a neuron cannot immediately fire again.

Neurotransmitter

Chemicals released by neurons to communicate with other neurons or cells.

EPSP

Excitatory Post-Synaptic Potential, moving membrane potential closer to threshold for an action potential.

IPSP

Inhibitory Post-Synaptic Potential, moving membrane potential further from threshold for an action potential.

Astrocytes

Glial cells that provide structural support and help maintain ion balance in the CNS.

Myelin Sheath

An insulating layer around axons, formed by oligodendrocytes in the CNS and Schwann cells in the PNS.

Cable Theory

Describes the electrical properties of axons, focusing on resistance and capacitance.

Endorphins

Peptides that reduce pain perception and produce feelings of pleasure.