Neuroscience: Nervous System Organization, Glial Cells, and Neural Electrophysiology

Comprehensive practice flashcards defining structural, functional, and electrophysiological vocabulary of the nervous system, including neuroimaging techniques, glial cell classes, neuronal anatomy, and resting membrane potentials.

EEG (Electroencephalography)

A brain monitoring method that reads brain activity with electrodes, records ongoing brain wave activity, and detects precisely when reactions occur within milliseconds.

MEG (Magnetoencephalography)

A brain recording technique that detects magnetic signals using magnetic fields, providing superior spatial localization compared to EEG.

Central Nervous System (CNS)

The nervous system division consisting of the brain and spinal cord that receives, interprets, and stores information, and issues commands.

Peripheral Nervous System (PNS)

Thick bundles of axons known as nerves that relay sensory information to the CNS, relay motor commands from the CNS to the body, and control voluntary and involuntary actions.

Sensory Division (Afferent)

The division of the peripheral nervous system responsible for picking up sensory stimuli from the environment and body.

Motor Division (Efferent)

The division of the peripheral nervous system that carries directional commands from the brain to muscles and glands.

Somatic Nervous System

The subdivision of the motor division that governs skeletal muscle movements and voluntary activity.

Autonomic Nervous System

The subdivision of the motor division that regulates involuntary bodily functions (such as heart rate and respiration) and comprises the sympathetic and parasympathetic systems.

Glial Cells

Non-neuronal cells described as the glue holding neurons together, providing physical support, nutrition, electrical insulation, and assistance with signal transmission.

Astrocytes

CNS glial cells that wrap around blood vessels and cell bodies, provide oxygen and blood supply, eliminate waste products from dead cells, and assist in synapse formation.

Microglial Cells

CNS glial cells that protect the brain from invading microorganisms by actively fighting viruses and fungi.

Oligodendrocytes

Glial cells in the central nervous system responsible for creating myelin sheaths around multiple neuronal axons.

Schwann Cells

Glial cells in the peripheral nervous system that form myelin sheaths around peripheral axons.

Radial Glia

Specialized glial cells that guide neuronal migration and facilitate the growth of axons and dendrites during embryonic development.

Myelination

The biological process of forming an insulating myelin sheath around neuronal axons to speed up nerve impulse transmission.

Myelin

An insulating lipid-rich layer encasing the axons of neurons that assists in preventing action potential dissipation and accelerates signal conduction.

Nodes of Ranvier

Gaps between sections of myelin sheath along an axon that contain sodium channels that open in response to an action potential.

Cell Body (Soma)

The core part of a neuron containing the nucleus that supports essential neuron functions.

Dendrites

Branch-like extensions of a neuron that primarily receive signals from other neurons, form connections, and transmit impulses toward the cell body.

Axon

The long, slender projection of a neuron that conducts electrical impulses away from the cell body toward target cells.

Axon Terminals

Specialized endings of an axon that release neurotransmitters to transmit signals and communicate with other neurons or effector cells.

Receptor / Sensory Neurons (Afferent)

Neurons highly sensitive to specific environmental stimuli (e.g., touch, light, sound) that receive sensory inputs, convert them into electrical impulses, and transmit them to other cells.

Motor Neurons (Efferent)

Neurons that carry out motor transduction, converting electrical signals from the nervous system into mechanical movement in muscles and glands.

Interneurons

Neurons within the central nervous system that act as the connection and integration points between sensory and motor neurons.

Membrane (Electrical) Potential

The difference in electrical charge between the intracellular interior and the extracellular exterior of a cell (neuron).

Resting Potential

The baseline membrane potential when a neuron is not firing, defined by $V_m = V_{\text{inside}} - V_{\text{outside}}$, commonly measured at approximately $-70\,\text{mV}$ inside the neuron.

Polarisation

The separation and presence of a difference in electrical charge between the inside and outside of the cell membrane.

Protein Ion Channels

Proteins embedded in the neuronal cell membrane that form pores allowing specific ions to pass across the membrane.

Transport Systems

Membrane-bound proteins that actively or selectively facilitate the movement of specific substances across the cell membrane.

Selective Permeability

The property of the neuronal cell membrane that permits certain chemical ions to pass through more freely than others.

Electrical Gradient

A gradient produced by the distribution of electrical charges across the membrane, determining where charged ions tend to move in combination with their concentration gradient.