👉 Periumbilical is a term used in medicine, specifically in the field of neurology, which refers to the process by which blood vessels that supply the brain and spinal cord move from one side to the other during sleep. This movement occurs because the brain and spinal cord are connected through the periaqueductal white matter (Paw) in the brain, and this connection is disrupted during sleep. The term "periumbilical" refers to the fact that this process can be interrupted
