Neural Circuits, EEG, and Seizures (Video Notes)

Vocabulary flashcards covering reflex pathways, EEG/ERP concepts, seizure types, and cortical mapping (Penfield homunculus).

Patellar tendon reflex

A knee-jerk stretch reflex of the quadriceps in response to tapping the patellar tendon.

Myelinated large-diameter axons

Axons with myelin and large diameter that conduct signals quickly, contributing to fast reflexes.

Monosynaptic reflex

A reflex arc with a single synapse directly between a sensory neuron and a motor neuron in the spinal cord.

Central synapse

A synapse located within the central nervous system (e.g., spinal cord).

Neuromuscular junction

The synapse between a motor neuron and a muscle fiber.

Receptor potential

Electrical change produced in a sensory receptor in response to a stimulus.

Postsynaptic potential

Electrical change in the postsynaptic neuron caused by neurotransmitter release.

Action potential

A rapid, all-or-none electrical impulse that travels along a neuron.

EEG (electroencephalogram)

A recording of spontaneous brain potentials (brain waves).

Brain waves

Oscillating electrical patterns recorded by EEG reflecting neural activity.

Event-related potentials (ERPs)

EEG responses that are time-locked to a specific stimulus, with distinctive shapes and latencies.

Latency

The time delay between a stimulus and the corresponding ERP component or response.

Epilepsy

A brain disorder characterized by recurrent seizures.

Seizure

A wave of abnormally synchronous electrical activity in the brain.

Tonic-clonic seizure

A generalized seizure with widespread abnormal EEG activity across the brain and convulsive movements.

Simple partial seizure

A focal seizure with localized EEG patterns lasting about 5–15 seconds, may occur multiple times per day.

Complex partial seizure

A focal seizure that does not involve the entire brain and is often preceded by an aura.

Aura

An unusual sensation or impression that sometimes precedes a focal seizure.

Homunculus

A cortical body-part map showing how body regions are represented in the motor and somatosensory cortex.

Wilder Penfield

Pioneer who mapped the cortex via electrical stimulation and described the cortical homunculus.

Postcentral gyrus

Primary somatosensory cortex; processes tactile and proprioceptive information.

Precentral gyrus

Primary motor cortex; initiates voluntary motor commands.

Central sulcus

The groove separating the precentral (motor) and postcentral (sensory) gyri.

Antiepileptic medications

Drugs used to control or prevent seizures.

Neurosurgery for seizures

Removal or disruption of brain tissue to stop seizures when medications fail.

Cortical stimulation

Electrical stimulation of the cortex to locate the seizure origin during surgical planning.

Sleep states

Distinct EEG-defined stages of sleep (e.g., REM and non-REM) used to diagnose sleep and brain activity patterns.