Action Potentials and Nervous System Vocabulary(lecture )

A comprehensive set of vocabulary flashcards covering key concepts related to the action potential and nervous system functions.

Resting Membrane Potential

The constant voltage across a cell membrane when the cell is not actively sending an impulse, typically around -70 mV.

Action Potential

A rapid change in voltage across the cell membrane that occurs when a neuron sends information down an axon.

Graded Potentials

Changes in membrane voltage that are small and add together to reach the threshold for an action potential.

Threshold

The specific level of depolarization that must be reached for an action potential to occur, typically around -55 mV.

Depolarization

The process of the cell membrane becoming less negative, often due to sodium ions entering the cell.

Repolarization

The process of the cell membrane returning to its resting negative state after depolarization.

Hyperpolarization

The state where the membrane potential becomes more negative than the resting potential.

Sodium-Potassium Pump

A membrane protein that helps maintain the resting membrane potential by pumping 3 sodium ions out and 2 potassium ions in.

Cation

An ion with a positive charge, such as sodium (Na+) or potassium (K+).

Anion

An ion with a negative charge.

Membrane Permeability

The ability of ions to pass through the cell membrane, which can differ for various ions.

Concentration Gradient

The difference in concentration of a substance across a distance, leading to the movement from high to low concentration.

Axon

The long, slender projection of a neuron that conducts electrical impulses away from the neuron's cell body.

Soma

The cell body of a neuron that contains the nucleus and organelles.

Synapse

The junction between two neurons where communication occurs.

Presynaptic Neuron

The neuron that sends the neurotransmitter across the synapse.

Postsynaptic Neuron

The neuron that receives the neurotransmitter at the synapse.

Neurotransmitter

Chemical messengers that transmit signals across a synapse from one neuron to another.

Propagation

The process of action potential traveling down the axon.

Refractory Period

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

Absolute Refractory Period

The phase following an action potential during which no new action potential can be initiated.

Relative Refractory Period

The phase following an action potential where it is possible to initiate another action potential, but requires a stronger stimulus.

Anesthetics

Medications that block nerve signals, preventing sensations of pain.

Myelin

A fatty substance that surrounds some axons, increasing the speed of signal transmission.

Demyelination

The loss of the myelin sheath around nerves, often leading to slower or disrupted nerve impulses.

Multiple Sclerosis

A disease characterized by damage to the myelin sheath in the central nervous system.

Guillain-Barré Syndrome

A temporary autoimmune disorder that causes the body’s immune system to attack the peripheral nerves.

Charcot-Marie-Tooth Disease

A genetic disorder that affects the peripheral nerves and can lead to muscle weakness.

Ion Channels

Proteins that allow ions to move across the membrane and are responsible for changes in membrane potential.

Voltage-Gated Channels

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

Resting State

The state of a neuron when it is not sending a signal, characterized by a negative charge.

Electrochemical Gradient

The combined difference in charge and concentration across a membrane that influences ion movement.

Neuronal Plasticity

The ability of neurons to change their connections and behavior in response to experiences.

Somatic Nervous System

Part of the peripheral nervous system associated with voluntary control of body movements.

Autonomic Nervous System

Part of the peripheral nervous system that controls involuntary body functions.

Sensory Neurons

Nerve cells that transmit sensory information to the central nervous system.

Motor Neurons

Nerve cells that transmit signals from the central nervous system to muscles or glands.

Interneurons

Neurons that connect sensory and motor neurons within the central nervous system.

Reflex Arc

The neural pathway that mediates a reflex action.

Central Nervous System (CNS)

Consists of the brain and spinal cord, responsible for processing and sending signals.

Peripheral Nervous System (PNS)

Consists of all the nerves outside the CNS that connect the brain and spinal cord to the rest of the body.

Cranial Nerves

Twelve pairs of nerves that emerge directly from the brain.

Spinal Nerves

Nerves that emerge from the spinal cord.

Somatic Reflexes

Reflexes that involve skeletal muscle responses.

Autonomic Reflexes

Reflexes that involve involuntary responses controlling smooth muscles.

Synaptic Cleft

The gap between the presynaptic and postsynaptic neuron across which neurotransmitters travel.

Reuptake

The process by which neurotransmitters are taken back into the presynaptic neuron after they have stimulated the postsynaptic neuron.

Diffusion

The passive movement of neurotransmitters away from the synaptic cleft.

Enzymatic Degradation

The breakdown of neurotransmitters by enzymes in the synaptic cleft.

Temporal Summation

The process of summating multiple graded potentials from a single presynaptic neuron over time.

Spatial Summation

The process of summating graded potentials from multiple presynaptic neurons simultaneously.

Oligodendrocytes

Glial cells in the CNS that produce myelin.

Schwann Cells

Glial cells in the PNS that produce myelin.

Meninges

Three protective membranes that cover the brain and spinal cord.

Cerebrospinal Fluid (CSF)

Fluid that circulates around and cushions the brain and spinal cord.

Blood-Brain Barrier

A selective permeability barrier that protects the brain from certain substances in the blood.

Neurological Disorders

Disorders that affect the nervous system, such as Parkinson's or Alzheimer’s.

Neuroglia

Supportive cells in the nervous system that do not transmit impulses.

Axon Hillock

The section of a neuron where the axon begins and action potentials are initiated.

Dendrites

Branch-like structures that receive signals from other neurons.

Resting Potential

The voltage difference across the membrane of a resting neuron.

Neuronal Threshold

The minimum voltage level required to trigger an action potential.

All-or-None Response

The principle that a neuron either fires completely or not at all.

Neural Pathways

A series of connected neurons that communicate information in the nervous system.

Excitatory Postsynaptic Potential (EPSP)

A postsynaptic potential that makes the neuron more likely to fire an action potential.

Inhibitory Postsynaptic Potential (IPSP)

A postsynaptic potential that makes a neuron less likely to fire an action potential.

Neuronal Firing Rate

The frequency at which a neuron fires action potentials based on the strength of the stimulus.

Phasic Response

A rapid response to a stimulus that diminishes quickly.

Tonic Response

A slow, sustained response to a stimulus.

Sensory Transduction

The process of converting external stimuli into electrical impulses in sensory neurons.

Peripheral Neuropathy

A condition resulting from damage to the peripheral nerves.

Cortex

The outer layer of the brain, involved in higher order brain functions.

Hippocampus

A brain area involved in memory formation.

Cerebellum

Part of the brain that regulates motor movements and coordination.

Hypothalamus

Brain region controlling homeostasis and various metabolic processes.

Thalamus

The brain's relay center for sensory information.

Corpus Callosum

The bundle of fibers connecting the left and right hemispheres of the brain.

Basal Ganglia

Group of nuclei in the brain associated with motor control.

Amygdala

Brain structure involved in emotion regulation, especially fear.

Frontal Lobe

Brain region responsible for executive functions, decision making, and motor control.

Parietal Lobe

Brain region associated with sensory processing and integration.

Temporal Lobe

Brain region associated with auditory processing and memory.

Occipital Lobe

Brain region primarily responsible for visual processing.

Motor Cortex

Part of the frontal lobe involved in the planning, control, and execution of voluntary movements.

Neuroplasticity

The ability to change and adapt neural pathways based on experience.

Nerve Impulse

The electrical signal that travels along a nerve fiber.

Neurogenesis

The process of forming new neurons in the brain.

Electrophysiology

The study of electrical properties of biological cells and tissues.

Peripheral Nervous System (PNS)

The network of nerves outside the brain and spinal cord.

Neuromuscular Junction

The synapse between a motor neuron and a skeletal muscle fiber.

Somatic Reflexes

Reflexes that involve the activation of skeletal muscles.

Autonomic Reflexes

Reflexes that involve involuntary control of organ systems.

Cell Membrane

The semipermeable membrane surrounding the cytoplasm of a cell.

Neurotransmitter Receptors

Proteins on the postsynaptic neuron that bind neurotransmitters and initiate a response.

Somatic Division

The part of the peripheral nervous system responsible for voluntary movements.

Sympathetic Nervous System

The division of the autonomic nervous system that prepares the body for fight or flight.

Parasympathetic Nervous System

The division of the autonomic nervous system that promotes rest and digest.

Electrode

A conductive device used to make contact with the body to detect or deliver electrical signals.

Nerve Fiber

Long threadlike part of a nerve cell along which impulses are conducted.

Glial Cells

Non-neuronal cells that support and protect neurons.