TAMU BIOL 320 LAB 2 EXAM 2025
QUESTIONS AND ANSWERS
Electoencephalograph (EEG) - ANS Electrical recording of activity of the brain
Brain waves - ANS Patters of neuronal electrical activity
Generated by synaptic activity at the surface of the cortex
responds to external stimuli and stages of arousal
-used in diagnosis epilepsy and brain death
Artifacts - ANS Unwanted interfering influences seen in EEGs
the EEG results from - ANS slow changes in the membrane potentials of cortical neurons,
especially the excitatory and inhibitory postsynaptic potentials
-reflects the algebraic sum of the electrical potential changes occurring
Wave frequency - ANS Number of peaks in 1 second
Amplitude - ANS Aka intensity
How high the wave peaks rise and how low the troughs dip
Reflects the synchronous activity of individual neurons
usually brain waves are complex and have low amplitude
Alpha waves - ANS 8 to 13 Hz
rhythmic, low amplitude
Copyright ©2025 BRIGHTSTARS ALL RIGHTS RESERVED 1
, Generally indicated a brain is 'idling' - a calm, relaxed state of wakefullness
Seen when eyes are closed and subject is relaxed
Strongest over occipital cortex and frontal cortex
the greater the cortical activity
Beta waves - ANS 13 to 30 Hz
Not as regular as alpha waves, higher frequency
Occur when mentally alert as when concentrating on some problem or visual stimulus
awake, alert individuals with their eyes open
greater cortical activity, the higher the beta wave activity
Theta waves - ANS 4 to 8 Hz
Common in awake children, seen when sleeping at all ages
Low theta (4-5.45 Hz): decreased arousal and increased drowsiness
High theta (6-7.45 Hz): enhanced during tasks involving working memory
Delta waves - ANS 0.5 to 4 Hz
High amplitude waves seen during deep sleep when the reticular activating system is damped
(such as in anesthesia)
In awake adults, indicate brain damage
Dominant rhythm in sleep stages 3 and 4
EEG artifacts caused by movements of jaw and neck muscles can produce waves in this same
frequency
Flat EEG - ANS Brain waves are flat, no spontaneous waves present
Clinical evidence of brain death
Consciousness - ANS Encompasses conscious perception of sensations, voluntary initiation
and control of movement, and capabilities associated with higher mental processing
Copyright ©2025 BRIGHTSTARS ALL RIGHTS RESERVED 2
QUESTIONS AND ANSWERS
Electoencephalograph (EEG) - ANS Electrical recording of activity of the brain
Brain waves - ANS Patters of neuronal electrical activity
Generated by synaptic activity at the surface of the cortex
responds to external stimuli and stages of arousal
-used in diagnosis epilepsy and brain death
Artifacts - ANS Unwanted interfering influences seen in EEGs
the EEG results from - ANS slow changes in the membrane potentials of cortical neurons,
especially the excitatory and inhibitory postsynaptic potentials
-reflects the algebraic sum of the electrical potential changes occurring
Wave frequency - ANS Number of peaks in 1 second
Amplitude - ANS Aka intensity
How high the wave peaks rise and how low the troughs dip
Reflects the synchronous activity of individual neurons
usually brain waves are complex and have low amplitude
Alpha waves - ANS 8 to 13 Hz
rhythmic, low amplitude
Copyright ©2025 BRIGHTSTARS ALL RIGHTS RESERVED 1
, Generally indicated a brain is 'idling' - a calm, relaxed state of wakefullness
Seen when eyes are closed and subject is relaxed
Strongest over occipital cortex and frontal cortex
the greater the cortical activity
Beta waves - ANS 13 to 30 Hz
Not as regular as alpha waves, higher frequency
Occur when mentally alert as when concentrating on some problem or visual stimulus
awake, alert individuals with their eyes open
greater cortical activity, the higher the beta wave activity
Theta waves - ANS 4 to 8 Hz
Common in awake children, seen when sleeping at all ages
Low theta (4-5.45 Hz): decreased arousal and increased drowsiness
High theta (6-7.45 Hz): enhanced during tasks involving working memory
Delta waves - ANS 0.5 to 4 Hz
High amplitude waves seen during deep sleep when the reticular activating system is damped
(such as in anesthesia)
In awake adults, indicate brain damage
Dominant rhythm in sleep stages 3 and 4
EEG artifacts caused by movements of jaw and neck muscles can produce waves in this same
frequency
Flat EEG - ANS Brain waves are flat, no spontaneous waves present
Clinical evidence of brain death
Consciousness - ANS Encompasses conscious perception of sensations, voluntary initiation
and control of movement, and capabilities associated with higher mental processing
Copyright ©2025 BRIGHTSTARS ALL RIGHTS RESERVED 2
