Chapter 19 Flashcards
(30 cards)
How many excited neurons does it take for an EEG to detect them?
Thousands
Pyramidal neurons make up about _______% of the brain’s mass.
80%
The amplitude of an EEG depends on how _____________ the activity is.
Synchronous
Which is the most important of these factors in an EEG signals?
A. Amount of neurons firing
B. The timing of the neurons firing
C. Total amount of excitation
B. Timing
When synchronous excitation is repeated, it creates ___________ EEG waves.
Large
Which is better at localizing sources of activity, MEG or EEG?
MEG
Which rhythms are the fastest? A. alpha B. Beta C. Gamma D. Theta E. Delta
B. Beta
________ rhythms run between 4-7 Hz.
Theta
_____________ rhythms run between 8-13 Hz.
Alpha
___________ rhythms run >14 Hz.
Beta
____________ rhythms run <4Hz.
Delta
Which rhythm is being produced during a quiet wakeful state?
Alpha
Which rhythm is produced during deep sleep?
Delta
A coma is defined as having a __________ frequency and _________ amplitude rhythm.
Low frequency, high amplitude
During sleep, synchrony is: high or low?
High
Hypothesis 1 of the reason for rhythms is it the brain’s way of…?
The brains way of disconnecting from sensory input
Hypothesis 2 of the reason for rhythms, is that rhythms are used to do what?
Rhythms are used to coordinate activity between different regions of the nervous system
Define generalized seizure.
Seizure happening in The entire cerebral cortex, both hemispheres
Define partial seizure.
A seizure happening in a circumscribed area of the cortex
One type of genetic predisposition for epilepsy/seizures is a mutated sodium channel. Explain.
The sodium channel is mutated to stay open for longer, allowing more sodium to come into the neurons, making them hyper excitable, setting off more action potentials.
One genetic predisposition to epilepsy/seizures is a mutation of GABA. Explain.
A mutation causing impairment of inhibition by GABA receptors.
A seizure can be defined as…
The most extreme form of synchronous brain activity.
What are convulsants?
Seizure promoting drugs that block GABA receptors.
What is an absence seizure? Who is most prone to this?
Seizure with dramatic brain activity, but little motor signs.
Most common in children.