A mid ocean ridge is made by a divergent boundary. The mid-ocean ridges of the world are connected and form a single global mid-oceanic ridge system that is part of every ocean. The mid-oceanic ridge system is the longest mountain range in the world. The continuous mountain range is 65,000 km (40,400 mi) long.
Circadian rhythms are important in determining human sleep patterns. The body's master clock, or SCN, controls the production of melatonin, a hormone that makes you sleepy. Since it is located just above the optic nerves, which relay information from the eyes to the brain, the SCN receives information about incoming light.
Care and Treatment for Sleep Disorders. An overnight sleep study, also called a polysomnogram, is a procedure which monitors body functions such as brain waves, heart rate, leg movements and breathing during sleep. You will be monitored by a sleep technologist all night long. There are different types of sleep studies.