Neuroscience: Graded Potentials and Neuronal Structures

This set of flashcards contains key terms and definitions related to graded potentials, action potentials, neuronal structure, and functions as discussed in neuroscience, helping students review for their exam.

Graded Potentials

Short-lived, localized changes in membrane potential caused by stimuli that open gated ion channels.

Receptor potential

Graded potentials in the receptors of sensory neurons.

Postsynaptic potential

Graded potential in the postsynaptic neuron.

Depolarization

A decrease in membrane potential, making the inside of the membrane less negative and increasing the chance of an impulse.

Hyperpolarization

An increase in membrane potential, making the inside of the membrane more negative and decreasing the chance of an impulse.

Changes in membrane potential

Alterations in the resting membrane potential due to changes in ion concentrations or permeability.

Incoming signals

Short-distance signals referred to as graded potentials.

Action potentials

Long-distance signals generated by axons.

Chemically gated channels

Ion channels that open in response to the binding of a specific chemical, such as a neurotransmitter.

Voltage-gated channels

Ion channels that open and close in response to changes in membrane potential.

Mechanically gated channels

Ion channels that open and close depending on physical deformation of receptors.

Ion channels

Large proteins that serve as selective conduits for ions to pass through membranes.

Leakage channels

Nongated ion channels that are always open.

Resistance

The hindrance to charge flow in electrical currents.

Current

The flow of electrical charge (ions) between two points.

Voltage

Measure of potential energy generated by separated charge, measured in volts (V) or millivolts (mV).

White matter

Regions in the brain and spinal cord with dense collections of myelinated fibers.

Gray matter

Regions primarily composed of neuron cell bodies and nonmyelinated fibers.

Multipolar neurons

Neurons with three or more processes (1 axon and multiple dendrites), common in the CNS.

Bipolar neurons

Neurons with two processes (one axon and one dendrite), rare and found in places like the retina.

Unipolar neurons

Neurons with one T-like process (two axons), also known as pseudounipolar.

Peripheral process

The distal part of a unipolar neuron that is associated with sensory receptors.

Central process

The proximal part of a unipolar neuron that enters the CNS.

Oligodendrocytes

Cells that form myelin sheaths in the central nervous system.

Myelin sheath gap

A gap present in the myelin sheath of an axon.

Anterograde transport

Movement of materials away from the cell body along the axon.

Retrograde transport

Movement of materials toward the cell body along the axon.

Dendrites

Armlike processes extending from the neuron cell body that receive signals.

Axon

A long process extending from a neuron that transmits impulses.

Neuron cell body

Also called the perikaryon or soma; the biosynthetic center of the neuron.

Nuclei

Clusters of neuron cell bodies located in the CNS.

Ganglia

Clusters of neuron cell bodies located in the PNS.

Ependymal cells

Cells that line the central cavities of the brain and spinal column and may aid in circulation of cerebrospinal fluid.

Microglial cells

Small, ovoid cells that monitor and protect neurons, capable of phagocytizing debris.

Cerebrospinal fluid (CSF)

Fluid that circulates in the brain and spinal column, providing protection and nutrients.

Nissl bodies

Rough ER found in the neuron cell body that synthesizes proteins.

Soma

Another term for the neuron cell body, which contains a nucleus and is responsible for cellular functions.

Perinuclear cytoplasm

The cytoplasmic region surrounding the nucleus of a neuron.

Chromatophilic substance

Rough ER in the neuron that synthesizes substances needed by the neuron.

Neuroglia

Supportive cells in the nervous system that assist and protect neurons.

Cilia

Hair-like structures on ependymal cells that may assist in circulating CSF.

Ion concentration gradients

Differences in ion concentrations across the membrane that can influence membrane potential.

Selective permeability

The ability of membranes to allow certain ions or molecules to pass while blocking others.

Signal molecules

Substances that can transmit signals within the nervous system.

Viruses in retrograde transport

Viruses that may move toward the neuron cell body via retrograde transport.

Neuronal debris

Damaged or unused cellular material that microglial cells can remove.

Skeletal proteins

Proteins involved in the cytoskeleton that support neuronal structure and transport mechanisms.