The pineal gland is a pea-sized mass of tissue attached by a stalk to the posterior wall of the third ventricle of the brain It may play a part in initiating development of the gonads, but this is not known In mammals, it secretes the hormone melatonin The gland becomes calcified as age progresses, providing a useful landmark in X-rays of the skull
{s} resembling a pine cone; pertaining to the pineal gland, pertaining to the small endocrine gland in the brain which secretes the hormone melatonin (Anatomy)
A small structure situated in the center of the head and connected to the brain that was originally the "third eye," which was located on the top of the head in primitive animals See also Melatonin
A small, cone-shaped organ in the brain of most vertebrates that secretes the hormone melatonin. Also called epiphysis, pineal body, pineal organ. or pineal body Endocrine gland in the brain that produces melatonin. It is large in children and begins to shrink at puberty. The gland may play a significant role in sexual maturation, circadian rhythm and sleep induction, and seasonal affective disorder and depression. In animals it is known to play a major role in sexual development, hibernation, and seasonal breeding