Neuro Key Terms

Franz Joseph Gall

Developed phrenology, linking brain areas to traits.

Jean Pierre Flourens

Used ablation studies to disprove phrenology, showing brain function is distributed.

Paul Broca

Identified Broca’s area, crucial for speech production.

Korbinian Brodmann

Mapped the cortex into Brodmann areas based on cellular structure and function.

Reticular Theory

Theory stating that neurons form a continuous nerve net.

Neuron Doctrine

Theory stating that neurons are individual cells that communicate at synapses.

Dendrites

Receive signals from other neurons.

Soma (Cell Body)

Contains the nucleus; controls metabolism and protein synthesis.

Axon

Transmits signals; action potentials begin at the axon hillock.

Axon Terminal

Releases neurotransmitters to communicate with the next neuron.

Astrocytes

Maintain blood-brain barrier, respond to injury by forming scar tissue.

Oligodendrocytes

Myelinate CNS axons (one oligodendrocyte myelinates multiple axons).

Schwann Cells

Myelinate PNS axons (one Schwann cell per axon).

Ependymal Cells

Line ventricles, produce cerebrospinal fluid (CSF).

Microglia

Act as the immune system of the CNS, removing debris and responding to injury.

Resting Membrane Potential (RMP)

≈ -65mV; negative inside neuron due to large proteins and K⁺ retention.

Concentration Gradient

Ions move from high to low concentration.

Electrical Gradient

Ions move toward opposite charges.

Electrochemical Gradient

Combination of concentration + electrical forces.

Sodium (Na⁺)

Drives depolarization; enters during action potential.

Potassium (K⁺)

Maintains resting potential; exits during repolarization.

Calcium (Ca²⁺)

Triggers neurotransmitter release at synapse.

Chloride (Cl⁻)

Helps regulate excitability by stabilizing membrane potential.

Action Potential

A rapid rise and subsequent fall in voltage or membrane potential across a cellular membrane.

Spike Initiation Zone

Located at the axon hillock, where action potentials start if depolarization reaches threshold.

Saltatory Conduction

Action potentials 'jump' between Nodes of Ranvier, speeding up signal transmission.

Multiple Sclerosis (MS)

Autoimmune attack on CNS myelin; slows down conduction.

Charcot-Marie-Tooth Disease

Genetic disorder affecting PNS myelin, causing muscle weakness.