Physiology Ppt: Eeg And Sleep

This story, titled The Night Shift at the Tower House is based on the real-life history of Alfred Loomis. It is designed to be told across your PPT slides to illustrate how EEG defines the physiology of sleep. Introduction: The Secret Laboratory In the mid-1930s, an eccentric Wall Street tycoon named Alfred Loomis retreated to his private mansion, known as the Tower House

Sleep is not merely an off-state of the brain but a dynamic, highly regulated physiological process essential for cognitive function, physical restoration, and overall health. While the average person sleeps for roughly a third of their life, the mechanisms governing this state have remained a profound mystery for much of modern science. We now understand that sleep disorders and insufficient rest are linked to an increased risk of cardiovascular disease, obesity, diabetes, and neurodegenerative diseases like dementia. To truly understand sleep, we must observe the electrical language of the brain, primarily through the .

– EEG criteria, scoring rules, and physiological characteristics.

"It is a common misconception that EEG records action potentials. It does not. Action potentials are too brief and asynchronous to be picked up by scalp electrodes. Instead, EEG records Post-Synaptic Potentials . Specifically, we are looking at the summation of electrical dipoles created by pyramidal neurons. When thousands of these neurons fire in synchrony—driven largely by thalamic pacemaker cells—we see a distinct wave pattern. If they fire asynchronously, the voltage cancels out, resulting in a low-amplitude, mixed-frequency signal." eeg and sleep physiology ppt

The appearance of the Alpha Rhythm (8–12 Hz), prominent over the occipital channels. EMG: High, active muscle tone. EOG: Blinks and rapid, voluntary eye movements. 2. Stage N1 (Light Sleep / Transition)

Process C is an internal, biological clock operating on a roughly 24-hour cycle.

Electroencephalography (EEG) is the cornerstone of sleep medicine, providing the primary "window" into the brain's activity during rest. By recording the electrical fluctuations of neurons via scalp electrodes, EEG allows researchers and clinicians to categorize sleep into distinct, physiological stages. The Mechanism of EEG in Sleep During wakefulness, the brain exhibits desynchronized This story, titled The Night Shift at the

Diagram of a pyramidal neuron in the cortex with EPSPs (Excitatory Post-Synaptic Potentials) occurring at the dendrites. Bullet Points:

Sample trace highlighting the differences between beta and alpha rhythms.

How does the brain know when to sleep? Two systems interact: While the average person sleeps for roughly a

Stage N2 forms the bedrock of a night's sleep, occupying roughly 45–55% of total sleep duration. This stage marks the definitive onset of true sleep.

: Prominent during drowsiness and light sleep (Stage N1).