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NERVOUS SYSTEM - Coggle Diagram
NERVOUS SYSTEM
changes that occur to the membrane that result in the action potential
Resting Membrane Potential
: Represents the membrane's equilibrium electrical potential difference in its unstimulated state, shaped by ion movement through various channels.
Depolarization
: Occurs when voltage-gated sodium channels open at the threshold potential, allowing sodium ions to enter the cell, leading to a surge in membrane potential.
Repolarization
: After the peak of the action potential, voltage-gated sodium channels close, and voltage-gated potassium channels open, enabling potassium ions to leave the cell, restoring the negative membrane potential.
Hyperpolarization
: Following repolarization, the membrane briefly goes below the resting potential, mainly due to open voltage-gated potassium channels, allowing excess potassium ions to exit.
Refractory Period
: After the action potential, the membrane enters a period where it can't generate another action potential, mainly because voltage-gated sodium channels become inactive, and voltage-gated potassium channels gradually close.
the components of the membrane that establish the resting membrane potential
Ion Channels
: Proteins allowing ion passage, with various types (voltage-gated, ligand-gated, and leak channels).
Ion Pumps
: Proteins actively moving ions against concentration gradients, including the Na+/K+ ATPase pump.
Concentration Gradients
: Differences in ion levels inside and outside the cell create gradients, primarily determined by K+ ions.
Permeability
: Selective membrane permeability to ions, with K+ having higher permeability.
the functional and structural differences between gray matter and white matter
Gray Matter
Pinkish-gray, contains neural cell bodies, axon terminals, dendrites, and synapses for information processing and signal release.
Abundant neurons in gray matter enable data processing and signaling in white matter.
Tan appearance with blood circulation, gray hue outside the body.
Present in the brain's outermost layer and spinal cord's interior.
White Matter
Bundles of axons extending from neuron cell bodies.
Located closer to the brain's core, while gray matter is in the outer cortex.
Axons are insulated with myelin, aiding signal conduction and protecting axons.
Functions in conducting, processing, and transmitting nerve signals in the spinal cord.
the difference between graded potential and action potential
Graded Potentials
Minor fluctuations in membrane potential due to external stimuli.
Can cause depolarization or hyperpolarization based on stimulus type.
Effects accumulate over time (temporal summation) and across locations (spatial summation).
Action Potentials
Rapid and significant changes in membrane potential, triggered at a specific threshold.
Action potentials initiate at the axon hillock and travel along the axon.
Always result in depolarization and a full reversal of the membrane potential.
Follow an "all-or-none" principle, either happening or not, with no accumulation.