what is the function of the pineal gland

The pineal gland is a small endocrine gland located in the center of the brain that helps regulate the bodys circadian rhythm by secreting the hormone melatonin. The main function of the pineal gland is to receive information about the daily light-dark cycle from the retinas in the eyes and then produce and release melatonin accordingly, with elevated levels at night and low levels during the day. Melatonin secretion is stimulated by darkness and inhibited by light, and it plays a vital role in regulating sleep patterns. The pineal gland consists of portions of neurons, neuroglial cells, and specialized secreting cells called pinealocytes, which create melatonin and secrete it directly into the cerebrospinal fluid. The pineal gland may also help regulate female hormone levels and contribute to cardiovascular health and mood stability. Pineal gland function and melatonin secretion can be impaired due to accidental and developmental conditions, such as pineal tumors, craniopharyngiomas, injuries affecting the sympathetic innervation of the pineal gland, and rare congenital disorders that alter melatonin secretion.