Neuroscience and Cellular Biology Foundations

Vocabulary practice flashcards covering fundamental neuroanatomy, cellular physiology, transport mechanisms, electrical signaling, and synaptic transmission based on Exam 1 course notes.

Sensory Systems

Neural systems that provide information about the state of the organism and its environment.

Motor Systems

Neural systems that organize and generate actions or movements.

Associational Systems

Neural systems that link sensory and motor components and support higher-order brain functions such as perception, attention, cognition, emotions, language, and rational thinking.

Reticular Theory

Theory associated with Camillo Golgi proposing that nerve cells are directly connected by protoplasmic links, forming one continuous nerve network.

Neuron Doctrine

Theory associated with Santiago Ramón y Cajal and Charles Sherrington stating that neurons are discrete, individual cells communicating via specialized contacts rather than a continuous network.

Gene Expression

The production of proteins from genetic information, following the central dogma of $\text{DNA} \rightarrow \text{RNA} \rightarrow \text{protein}$.

Transcription Factors

Proteins that become activated, enter the nucleus, and bind DNA to enhance or turn off transcription, regulating gene expression.

Neurons

Cells in the nervous system specialized to carry out electrical signaling over long distances and moment-to-moment communication.

Glial Cells

Supportive cells in the nervous system that help maintain conditions needed for neuronal function.

Dendrites

Receptive regions of a neuron where incoming signals enter.

Axon Hillock

The region where the axon begins and where action potentials are initiated and propagated from.

Axon Terminals

The secretory region of a neuron where signals leave the cell, including neurotransmitter release.

Nodes of Ranvier

Gaps in the myelin sheath where voltage-gated channels are concentrated and action potentials are regenerated during saltatory conduction.

Convergence

The number of inputs received by a single neuron.

Divergence

The number of targets innervated by a single neuron.

Synaptic Transmission

The chemical and electrical processes by which information encoded by action potentials is passed across synaptic contacts to a target cell.

Astrocytes

Glial cells with star-like processes that maintain the appropriate chemical environment for neuronal signaling.

Oligodendrocytes

Glial cells that produce myelin in the central nervous system (CNS) and can wrap multiple axons.

Schwann Cells

Glial cells that produce myelin in the peripheral nervous system (PNS), where one cell myelinates one axon segment.

Microglia

Scavenger/macrophage-like cells in the nervous system that remove cellular debris after injury or turnover and secrete cytokines.

Afferent Neuron

A neuron that carries information from the periphery toward the brain or spinal cord.

Efferent Neuron

A neuron that carries information away from the brain or spinal cord toward effectors.

Interneuron

A local circuit neuron lying between sensory and motor neurons, typically possessing a short axon within the CNS.

Multipolar Neuron

A neuron with $3$ or more processes ($1$ axon and multiple dendrites); it is the most common structural type in the CNS.

Bipolar Neuron

A rare structural type of neuron with $2$ processes ($1$ axon and $1$ dendrite), found in retina and olfactory mucosa.

Unipolar Neuron

A neuron with $1$ short process that divides in a T-shape into central and peripheral axonal branches; typical of sensory neurons.

Ganglia

Collections of neuron cell bodies located in the PNS.

Nuclei

Local collections of neuron cell bodies located within the CNS.

Tracts

Groups of axons within the CNS, analogous to nerves in the PNS.

Commissures

Axon tracts in the CNS that cross the midline of the brain.

Gray Matter

Any accumulation of neuron cell bodies in the CNS.

White Matter

Myelinated axon tracts in the CNS.

fMRI (Functional Magnetic Resonance Imaging)

A functional imaging technique that detects blood-related changes/concentrations to identify active brain regions.

Peripheral Membrane Proteins

Proteins associated indirectly with the cell membrane through protein-protein interactions (often ionic bonds) without inserting into the bilayer.

Integral Membrane Proteins

Proteins inserted directly into the lipid bilayer held by hydrophobic interactions.

Facilitated Diffusion

Movement of polar or charged substances down a concentration gradient without energy, utilizing membrane transport proteins.

Carrier Proteins

Transport proteins that bind a target molecule on one side of the membrane, undergo a conformational change, and release it on the other side.

Channel Proteins

Transport proteins that form open pores allowing rapid passage of specific molecules based on size and charge.

$\text{Na}^+\text{-K}^+$ ATPase

An active transport pump that uses $1$ ATP to move $3\,\text{Na}^+$ out of the cell and $2\,\text{K}^+$ into the cell.

Phagocytosis

A type of vesicular transport where pseudopodia surround a particle to form a phagosome, which then fuses with a lysosome for digestion.

Autophagy

A regulated cellular process in which a cell degrades and recycles its own internal components and organelles.

Resting Membrane Potential (RMP)

The electrical potential difference across the plasma membrane of a resting neuron, approximately $-70\,mV$.

Graded Potentials

Short-lived, localized electrical signals whose magnitude varies directly with stimulus strength and decays over distance.

Action Potential

A brief reversal of membrane potential of about $100\,mV$ that operates on an all-or-none principle and propagates long distances without decaying.

Absolute Refractory Period

The timeframe from the opening of voltage-gated $\text{Na}^+$ channels until they reset, during which no second action potential can be fired.

Relative Refractory Period

The period following the absolute refractory period where most $\text{Na}^+$ channels have reset but some $\text{K}^+$ channels remain open, requiring an exceptionally strong stimulus to reach the elevated threshold.

Saltatory Conduction

Rapid conduction in myelinated axons where action potentials jump from one myelin sheath gap (Node of Ranvier) to the next.

Multiple Sclerosis (MS)

An autoimmune disorder targeting CNS oligodendrocytes and myelin, resulting in current leakage and significantly slowed action-potential conduction.

Synaptic Delay

The time duration required for neurotransmitter release, diffusion across the synaptic cleft, and receptor binding, lasting about $0.3\text{ to }5.0\,ms$.

EPSP (Excitatory Postsynaptic Potential)

A local depolarizing graded potential that increases the likelihood of reaching action-potential threshold.

IPSP (Inhibitory Postsynaptic Potential)

A local hyperpolarizing graded potential that moves membrane potential further from threshold, making an action potential less likely.

Temporal Summation

Summation occurring when multiple presynaptic signals arrive in rapid succession at a single synapse close together in time.

Spatial Summation

Summation occurring when multiple presynaptic inputs stimulate the postsynaptic cell simultaneously at different locations.

Long-Term Potentiation (LTP)

A form of synaptic plasticity in the hippocampus where specific activity patterns produce a long-lasting increase in synaptic strength via AMPA and NMDA receptor activation.