Week 1 Flashcards
Intro to Nervous System & Neuroplasticity
Term
Definition
Astrocytes
Glial cells that support neurons, anchor them to blood supply, and help form the blood-brain barrier.
Protoplasmic Astrocytes
Type of astrocyte found in gray matter with thick, branched processes.
Fibrous Astrocytes
Type of astrocyte found in white matter with long, thin, unbranched processes.
Microglial Cells
Glial cells that monitor neuronal health and can morph into macrophages to phagocytose pathogens or dead neurons.
Ependymal Cells
Cells that form a barrier between cerebrospinal fluid and brain/spinal cord tissue; help circulate CSF.
Oligodendrocytes
Glial cells that create the myelin sheath in the central nervous system (CNS).
Satellite Cells
Small cells that surround neuronal cell bodies in the peripheral nervous system (PNS) and provide support.
Schwann Cells
Glial cells that form the myelin sheath in the peripheral nervous system (PNS).
Central Nervous System (CNS)
Consists of the brain and spinal cord.
Peripheral Nervous System (PNS)
Consists of sensory (afferent) and motor (efferent) neurons.
Somatic Nervous System (SNS)
The part of the nervous system that controls voluntary movements.
Autonomic Nervous System (ANS)
The part of the nervous system that controls involuntary functions.
Sympathetic Nervous System
Division of the autonomic nervous system responsible for fight-or-flight response.
Parasympathetic Nervous System
Division of the autonomic nervous system responsible for rest-and-digest functions.
Enteric Nervous System
The nervous system of the gastrointestinal tract.
Sensory Neurons (Afferent)
Transmit sensory information from the body to the CNS.
Motor Neurons (Efferent)
Transmit motor commands from the CNS to muscles.
Interneurons
Neurons that connect other neurons within the CNS.
Neuroendocrine Cells
Specialized neurons that release hormones into the bloodstream.
Dendrites
Neuron structures that receive incoming signals.
Cell Body
Contains organelles for synthesis and processing of proteins and other materials.
Axon
Transmits electrical signals away from the cell body.
Axon Terminals
Regions where neurons communicate with other cells via synapses.
Myelin Sheath
A protective layer around axons that increases the speed of signal transmission.
Nodes of Ranvier
Gaps between myelin sheath segments that facilitate rapid signal conduction.
Axon Hillock
The triangular region of a neuron where action potentials are initiated.
Synapse
The junction where a neuron communicates with another cell by releasing neurotransmitters.
Transmembrane Ion Channel
A protein that allows ions to pass across the cell membrane.
Non-Gated Ion Channel
An ion channel that is always open, allowing ions to pass freely.
Gated Ion Channel
An ion channel that opens or closes in response to specific stimuli.
Chemically-Gated Ion Channel
An ion channel that opens or closes in response to a neurotransmitter.
Voltage-Gated Ion Channel
An ion channel that opens or closes in response to changes in electrical charge.
Mechanically-Gated Ion Channel
An ion channel that opens or closes in response to pressure or mechanical stress.
Refractory Period
The time when an ion channel is unable to open, preventing further ion movement.
Ion Selectivity
The ability of an ion channel to allow specific ions to pass based on size and charge.
Hydrated Ion Size
The combined size of an ion and its surrounding water molecules, affecting ion channel selectivity.
Resting Membrane Potential (RMP)
The electrical charge difference across a neuron’s membrane at rest (-70 mV).
Depolarization
When the membrane potential becomes less negative.
Hyperpolarization
When the membrane potential becomes more negative.
Selective Permeability
The property of a membrane that allows only certain ions to pass through.
Equilibrium Potential
The voltage at which the movement of an ion across the membrane is balanced.
Nernst Equation
An equation used to calculate the equilibrium potential for a single ion.
Goldman Equation
An equation that calculates membrane potential considering multiple ions and their permeabilities.
Sodium-Potassium Pump
A membrane protein that actively transports 3 Na+ out and 2 K+ into the cell using ATP.
Action Potential
A rapid electrical signal that travels along the neuron.
Graded Potential
A small change in membrane potential that operates over short distances.
Threshold
The membrane potential level required to trigger an action potential.
Neuroplasticity
The brain’s ability to reorganize and adapt by forming new neural connections.
Structural Neuroplasticity
Changes in the physical structure of neural networks due to learning and experience.
Functional Neuroplasticity
The brain’s ability to reassign functions from damaged areas to undamaged areas.
Synaptic Plasticity
Changes in the strength of synaptic connections due to experience and activity.
Long-Term Potentiation (LTP)
A process where synapses strengthen over time, improving communication between neurons.
Long-Term Depression (LTD)
A process where synapses weaken over time, reducing communication between neurons.
Transcranial Direct Current Stimulation (tDCS)
A brain stimulation technique that applies weak electrical currents to modulate cortical excitability.
Anodal Stimulation
Positive electrode stimulation that depolarizes neurons, increasing excitability.
Cathodal Stimulation
Negative electrode stimulation that hyperpolarizes neurons, decreasing excitability.
Transcranial Magnetic Stimulation (TMS)
A technique using magnetic fields to induce electric currents in the brain and influence neural activity.
Repetitive TMS (rTMS)
A form of TMS that can induce long-term changes in brain excitability.
High-Frequency rTMS
Increases cortical excitability and promotes long-term potentiation (LTP).
Low-Frequency rTMS
Decreases cortical excitability and induces long-term depression (LTD).
