Neurotransmissions & Action Potentials

A comprehensive set of flashcards covering key concepts related to neurotransmissions and action potentials, designed to aid in exam preparation.

Neurotransmission

The process of communication between neurons through the release and reception of neurotransmitters.

Action Potential

A brief reversal of membrane potential that occurs when a neuron is stimulated past a threshold level.

Resting Membrane Potential

The charge difference across a neuron's membrane when it is not actively transmitting a signal, usually around -70mV.

Diffusion

The movement of ions from an area of high concentration to an area of low concentration.

Concentration Gradient

The difference in concentration of a substance across a space that allows for diffusion to occur.

Voltage Gradient

The difference in electric charge between two regions that influences ion movement.

Sodium (Na+)

A positively charged ion that contributes to depolarization during an action potential.

Chloride (Cl-)

A negatively charged ion that is found at a higher concentration outside the neuron at rest.

Potassium (K+)

A positively charged ion that is found at a higher concentration inside the neuron at rest.

Large Protein Molecules (A-)

Negatively charged proteins inside the cell that contribute to the resting membrane potential.

Semipermeable Membrane

A membrane that selectively allows certain ions or molecules to pass through while blocking others.

Graded Potentials

Small changes in membrane potential in response to stimuli, which can lead to action potentials if large enough.

Excitatory Postsynaptic Potential (EPSP)

A brief depolarization of the postsynaptic membrane, making it more likely to fire an action potential.

Inhibitory Postsynaptic Potential (IPSP)

A brief hyperpolarization of the postsynaptic membrane, making it less likely to fire an action potential.

Threshold Potential

The membrane voltage at which an action potential is triggered, typically around -50mV.

Sodium-Potassium Pump

A protein that transports Na+ out of the cell and K+ into the cell, helping to maintain the resting membrane potential.

All-or-None Law

The principle stating that an action potential is either generated fully or not at all; it does not diminish as it travels.

Saltatory Conduction

The rapid propagation of action potentials along myelinated axons, jumping from node to node.

Myelin Sheath

An insulating layer around axons that speeds up the conduction of nerve impulses.

Node of Ranvier

Gaps in the myelin sheath where voltage-sensitive ion channels are concentrated, facilitating rapid signal propagation.

Oligodendroglia

Glial cells in the central nervous system responsible for producing myelin.

Schwann Cells

Glial cells in the peripheral nervous system that produce myelin.

Membrane Potential

The difference in electric charge across the cell membrane.

Depolarization

A decrease in the membrane potential, making the inside of the cell more positive.

Hyperpolarization

An increase in the membrane potential, making the inside of the cell more negative.

Voltage-sensitive Channels

Protein channels that open or close in response to changes in membrane voltage.

Electrical Activity

The movement of ions across the neuronal membrane, leading to changes in membrane potential.

Intracellular Fluid

The fluid found within cells, containing a high concentration of K+ and large proteins.

Extracellular Fluid

The fluid outside of cells, containing a high concentration of Na+ and Cl-.

Ion Movement

The process by which ions move across membranes, contributing to electrical signals in neurons.

Neuronal Communication

The process through which neurons send and receive signals to and from each other.

Na+ Influx

The movement of sodium ions into the neuron, leading to depolarization.

K+ Efflux

The movement of potassium ions out of the neuron, leading to repolarization.

Charge Distribution

The arrangement of ions within and outside the neuron that creates a membrane potential.

Ion Channels

Proteins that allow ions to pass through the cell membrane, often gated by voltage changes.

Resting State

The state of a neuron when it is polarized, with a stable resting membrane potential.

Neuronal Threshold

The critical level of depolarization that must be reached to initiate an action potential.

Ionic Concentrations

The distribution of various ions inside and outside of the neuron, which affects membrane potential.

Protein Gates

Channels in the membrane that can open or close to allow specific ions to enter or leave the cell.

Membrane Stimulation

The process of increasing the membrane potential that can lead to action potential generation.

Nerve Impulse Propagation

The process by which an action potential travels along the axon membrane.

Membrane Reversal

The process where the inside of the neuron becomes more positive relative to the outside during an action potential.

Chemical Gradients

Differences in ion concentration that drive the movement of ions across membranes.

Electrical Gradients

Differences in charge that influence how ions move across the neuronal membrane.

Signal Transmission

The process by which electrical signals are conveyed along the neuronal axon.

Repolarization

The process of returning the membrane potential back to resting potential after depolarization.

Excitation Threshold

The level of stimulus required to initiate an action potential in a neuron.

Ion Transporters

Proteins that move ions across the cell membrane in active and passive ways.

Resting Ion Distribution

The state of ion concentrations inside and outside of a neuron, with high K+ inside and high Na+ outside.

Neuronal Plasticity

The ability of neurons to change their connections and behavior based on input and experience.

Membrane Dynamics

The changes in membrane potential due to ion movements during stimulation.

Ion Leakage

Unintentional movement of ions across the membrane that can influence the resting potential.

Channel Opening Mechanism

The process by which ion channels open in response to membrane voltage changes.

Synchronization of Action Potentials

The alignment of action potentials across adjacent segments of the axon to propagate a signal.

Energetic Efficiency

The energy-saving aspect of saltatory conduction due to fewer action potentials needing to be generated.

Neurotransmitter Release

The expulsion of neurotransmitters into the synaptic cleft, allowing signal transmission between neurons.

Synaptic Transmission

The process of transferring signals across synapses through neurotransmitters.

Cell Membrane Structure

The arrangement of lipids and proteins that constitutes the neuronal membrane.

Ion Channel Classification

The categorization of ion channels based on their properties and gating mechanisms.

Neuropharmacology

The study of how drugs affect the nervous system and neuronal function.

Pain Transmission

The relay of pain signals through neurons in response to harmful stimuli.

Neuromuscular Junction

The synapse between a motor neuron and a muscle fiber that facilitates contraction.

Axon Hillock

The junction where the axon meets the cell body; crucial for action potential initiation.

Synaptic Plasticity

Changes in the strength of synaptic connections as a result of activity.

Resting State Stability

How the neuron maintains its resting membrane potential despite fluctuations.

Ionic Homeostasis

The maintenance of consistent ion concentrations within neuronal environments.

Biological Signal Processing

The handling of information processing by neurons through electrical and chemical signals.

Potential Gradient

The difference that drives ions to move from one area to another based on voltage.

Neural Regulation

The mechanisms that control the activity of neurons and their networks.

Neuroscience Research

Investigations aimed at understanding the functioning of the nervous system.

Pathophysiology

The study of how diseases affect physiological processes, including neuronal function.

Cyclic Changes in Potential

Fluctuations in the membrane potential as a neuron responds to stimuli.

Transmembrane Potential Changes

Variations in the electric potential difference across a neuronal membrane.

Depolarized State

The condition where the inside of a neuron becomes less negatively charged relative to resting potential.

Ion Selectivity

The characteristic of ion channels that allows them to preferentially allow certain ions to pass.

Neuronal Communication Networks

The interconnected pathways through which neurons transmit signals.

Nerve Signal Transmission Speed

The speed at which action potentials propagate along axons.

Action Potential Characteristics

The features of action potentials including initiation, propagation, and termination.

Ion Channel Gating

The mechanism by which ion channels open or close in response to stimuli.

Electrophysiology

The study of the electrical properties of biological cells and tissues.

Neurotransmitter Receptor Sites

Specific locations on the postsynaptic membrane where neurotransmitters bind.

Nerve Function Disorders

Pathologies altering normal neuronal communication and signal propagation.

Electrode Recording Techniques

Methods used to measure the electrical activity of neurons.

Selectivity Permeability

The ability of a membrane to allow certain ions to pass while excluding others.

Neuronal Excitability

The ability of a neuron to respond to stimuli and generate action potentials.

Axonal Propagation Mechanisms

The processes involved in the transmission of action potentials down the axon.

Neurotransmitter Dynamics

The release, binding, and degradation of neurotransmitters during synaptic transmission.

Myelination Process

The formation of myelin sheaths around axons, enhancing signal conduction.

Neuronal Differentiation

The process through which neurons develop distinct functional properties.

Calcium Ions (Ca2+)

Ions that play a crucial role in neurotransmitter release at synapses.

Neurotransmitter Types

The classifications of neurotransmitters based on their chemical structure and function.

Glial Cell Functions

The supportive roles of glial cells in the nervous system, including insulation, support, and nourishment.

Neural Integration

The process by which multiple signals are combined in a neuron instead of being processed independently.

Electrochemical Gradients

The combined effect of concentration and voltage gradients on ion movement.

Failure to Fire

A condition in which a neuron does not generate an action potential despite stimulation.

Conduction Velocity Factors

The variables affecting the speed of action potential propagation along axons.

Refractory Period

The time following an action potential during which a neuron is less responsive to further stimulation.

Neural Crest Cells

Cells that contribute to the development of neurons and glial cells during embryogenesis.

Anatomical Properties of Neurons

The physical characteristics that define the structure and function of neurons.

Chemical Synapses

Connections between neurons that involve neurotransmitter release across a synaptic cleft.