ascending midbrain reticular activating system
Quick Summary
The ascending reticular activating system (ARAS) is a crucial part of the brainstem and midbrain that regulates arousal and alertness. When this system is active, an individual is awake, alert, and attentive. Damage to the ARAS can lead to unresponsiveness, confusion, or unconsciousness, even if sensory pathways are intact.1
The ARAS receives input from various sensory pathways and projects to the cerebral cortex via the thalamus. Unlike primary sensory pathways that are specific to one sense, many ARAS cells respond to signals from any sensory modality. This system is fundamental to maintaining wakefulness and plays a role in the sleep-wake cycle. Moment-to-moment shifts in attention are thought to involve a diffuse thalamic projection system connected to the ARAS. The ARAS works in conjunction with the cerebral cortex and other brain regions to process sensory information and mobilize resources.1
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motivationThe inverted-U function…the brain stem named the reticular activating system, or reticular formation. These cells, which are found along the center of the brain stem, run from the medulla to the thalamus and are responsible for changes in arousal that move a person from sleeping to waking. They are also believed to…
Read More…the brain stem named the reticular activating system, or reticular formation. These cells, which are found along the center of the brain stem, run from the medulla to the thalamus and are responsible for changes in arousal that move a person from sleeping to waking. They are also believed to…
Read More- sleepNeural theories
With the discovery of the ascending reticular activating system (ARAS; a network of nerves in the brainstem), it was found that it is not the sensory nerves themselves that maintain cortical arousal but rather the ARAS, which projects impulses diffusely to the cortex from the brainstem. Presumably, sleep would result…
Read MoreWith the discovery of the ascending reticular activating system (ARAS; a network of nerves in the brainstem), it was found that it is not the sensory nerves themselves that maintain cortical arousal but rather the ARAS, which projects impulses diffusely to the cortex from the brainstem. Presumably, sleep would result…
Read More