Neuroscience and Physiology of Neurons

Flashcards to help review key concepts and terminology related to neurons and the nervous system.

Neuron

A nerve cell that transmits electrical signals in the nervous system.

Dendrites

The branched projections of a neuron that receive electrical signals.

Axon

The long, thin structure that transmits electrical impulses away from the neuron's cell body.

Synapse

The junction between two neurons where communication occurs.

Action Potential

A rapid change in membrane potential that propagates along an axon.

Resting Membrane Potential

The electrical potential difference across a neuron membrane when at rest, usually around -70 mV.

Graded Potential

A variable strength signal that decays as it travels through the neuron.

Threshold

The level of voltage change needed to trigger an action potential.

Myelin Sheath

An insulating layer around the axon that speeds up electrical transmission.

Saltatory Conduction

The process by which action potentials jump from one Node of Ranvier to another along a myelinated axon.

EPSP (Excitatory Postsynaptic Potential)

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

IPSP (Inhibitory Postsynaptic Potential)

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

Neurotransmitter

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

Voltage-gated Channels

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

Chemical Synapse

A synapse where neurotransmitters are released to transmit signals between neurons.

Electrical Synapse

A synapse that transmits signals through direct electrical connections.

Glial Cells

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

Oligodendrocytes

Glial cells in the CNS that form myelin sheaths around axons.

Schwann Cells

Glial cells in the PNS that form myelin sheaths around a single axon.

Astrocytes

Star-shaped glial cells that maintain homeostasis and support neurons.

Microglia

Immune cells in the central nervous system that act as macrophages.

Neurotrophic Factors

Proteins that aid in the growth, survival, and differentiation of neurons.

Central Nervous System (CNS)

The part of the nervous system consisting of the brain and spinal cord.

Peripheral Nervous System (PNS)

The part of the nervous system that connects the CNS to the rest of the body.

Afferent Neurons

Sensory neurons that carry information to the CNS.

Efferent Neurons

Motor neurons that carry signals away from the CNS to effectors.

Synaptic Cleft

The small gap between a presynaptic neuron and a postsynaptic neuron.

Feedback Loop

A process in which the output of a system affects its own input.

Electrochemical Gradient

The difference in concentration and charge across a membrane, driving ion movement.

Na+/K+ Pump

An enzyme that pumps sodium out of and potassium into the cell, crucial for maintaining resting potential.

Permeability

The ability of the cell membrane to allow specific ions to pass through.

Refractory Period

The time following an action potential during which a neuron cannot produce another action potential.

Absolute Refractory Period

The period during which no action potential can be initiated, regardless of stimulus strength.

Relative Refractory Period

The period following an action potential during which a larger-than-normal stimulus is required to elicit another action potential.

Neurotransmitter Receptors

Proteins on the postsynaptic cell that bind neurotransmitters and mediate their effects.

Spatial Summation

The process by which multiple synaptic potentials combine at the axon hillock.

Temporal Summation

The process by which multiple signals received at different times add together.

Neuronal Circuit

A group of interconnected neurons that work together to process specific types of information.

Long-Term Potentiation (LTP)

A long-lasting enhancement in signal transmission between two neurons that results from stimulating them simultaneously.

Neural Plasticity

The ability of the nervous system to change its activity in response to intrinsic or extrinsic stimuli.

Convergence

The process through which multiple inputs converge onto a single neuron.

Divergence

The process through which a single neuron branches out to multiple targets.

Norepinephrine

A neurotransmitter involved in the fight-or-flight response.

Acetylcholine

The neurotransmitter that activates skeletal muscles and mediates parasympathetic nervous system functions.

Psychoactive Drugs

Substances that affect mood, perception, or behavior by altering neurotransmitter function.

Multiple Sclerosis

A demyelinating disease affecting the central nervous system.

Alzheimer's Disease

A progressive neurodegenerative disorder characterized by memory loss and cognitive decline.

Parkinson's Disease

A neurodegenerative disorder characterized by tremors and movement difficulties.

Hypothalamus

Brain region controlling homeostasis, emotions, and endocrine functions.

Pituitary Gland

The endocrine gland that secretes hormones controlling various body functions.

Thalamus

The brain's relay station for sensory and motor signals.

Medulla Oblongata

Part of the brain stem that controls vital autonomic functions.

Corpus Callosum

Nerve fibers connecting the left and right cerebral hemispheres.

Limbic System

The brain region involved in emotion, memory, and arousal.

Cerebral Cortex

The outer layer of the cerebrum responsible for higher brain functions.

Cerebellum

The brain structure coordinating movement and balance.

Neuroplasticity

The ability of the brain to reorganize itself by forming new neural connections.

Electrical Signals

Changes in voltage across a neuronal membrane due to ion movement.

Resting Potential

The stable, negative charge of a neuron at rest, typically around -70 mV.

Hyperpolarization

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

Depolarization

A decrease in membrane potential making the inside of the cell less negative.

Node of Ranvier

Gaps in the myelin sheath of an axon where ion exchange occurs during action potentials.

Cation

A positively charged ion.

Anion

A negatively charged ion.

Ion Channel

Protein structures that allow specific ions to pass through the neuronal membrane.

Signal Transduction

The process by which a cell converts an extracellular signal into a functional response.

Phospholipid Bilayer

The fundamental structure of cell membranes, composed of lipid molecules.

Homeostasis

The process of maintaining a stable internal environment within an organism.

Neurogenic

Related to the growth or development of neurons.

Stem Cells

Uns specialized cells capable of differentiation into various cell types.

Hypoglycemia

Decreased blood glucose level that can lead to confusion and unconsciousness.

Metabolism

The sum of all chemical reactions occurring in the body to maintain life.

Anabolism

The metabolic process of building up larger molecules from smaller ones.

Catabolism

The metabolic process of breaking down larger molecules into smaller ones.

Glucagon

A hormone that raises blood glucose levels by stimulating glycogen breakdown.

Insulin

A hormone that lowers blood glucose levels by promoting glucose uptake.

Body Temperature Regulation

The process of maintaining a stable internal temperature in the body.

Thyroid Hormones

Hormones that regulate metabolism and energy usage.

Somatic Nervous System

Part of the PNS that controls voluntary movements of skeletal muscles.