Reticular activating system (RAS) or the ascending arousal system consists of nuclei and tracts and is involved in the regulation of wakefulness, sleep aspects and arousal.
RAS is located in the mesopons and interacts with the basal forebrainand thalamocortical systems. It activates the cerebral cortex and thereby maintain the consiusness. The neurons located at the pontomesencephalic junctionparticipates in this activity of arousal.
Explanation: Prophase, is the first and longest phase of mitosis. First, chromtain condense it into chromosomes and the nuclear membrane breaks it down.
