A tiny gland located in the middle of the brain, it is involved (in the presence of light through the eyes) in the conversion of the amino acid tryptophan into the neurotransmitter serotonin and (in the absence of light through the eyes) of the neurotransmitter serotonin into the hormone melatonin. Biologically, it is composed of nerve cells; functionally, it is considered to be a master gland of the endocrine system. In the brain, it has reciprocal links with the thalamus, hypothalamus, hippocampus and amygdala; in the endocrine system it has reciprocal links with the pituitary gland, thymus gland, thyroid gland, parathyroid glands and adrenal glands. It is involved in the regulation of cycles, immune system functioning and other hormones and is said to be extremely sensitive to Electro-Magnetic Radiation. See text, Chapter 4. See also, "biological clock," "Electro-Magnetic Sensitivity," "hormone," "melatonin," "neurohormone, " "neurotransmitter" and "serotonin."

Neural tissue in the posterior portion of the roof of the diencephalon; secretes melatonin.

A cone-shaped structure in the brain; it releases the sleep-inducing hormone melatonin.

An neurosecretory gland, responsive to light and responsible for the production and secretion of melatonin.

small gland that helps regulate the biological clock; at the base of the brain.

a cone-shaped gland located in the roof of the third ventricle; also called the epiphysis cerebri

a human endocrine gland in the midbrain that regulates mating behaviors and day-night cycles.

endocrine gland named as shape resembles a pine cone. Formed from a dorsal outpocket of diencephalon. The hormone melatonin (high in dark, low in day) involved with the diurnal cycle, inhibits pituitary-gonad axis. (More? Endocrine Notes | Pineal Gland)

a small endocrine gland in the brain; situated beneath the back part of the corpus callosum; secretes melatonin

A cone-shaped pea-size structure in mid-brain that produces melatonin. [See Melatonin

pie-NE-al GLAND A small oval structure in the brain that produces melatonin, a hormone that senses light and dark periods. 675

(PIN-ee-al) A tiny organ in the cerebrum that produces melatonin. Also called pineal body or pineal organ.

small gland attached by a stalk to the third ventricle of the brain that produces the hormone melatonin that is synthesized from serotonin. Melatonin release is influenced by light.

A small cone-shaped component of the epithalamus attached in the midline by a stalk to the dorsocaudal 3rd ventricle. Also known as the epiphysis cerebri. This endocrine organ secretes serotonin and melatonin in sync with light cycles. Prior to puberty the pineal exerts an inhibitory influence of the reproductive system. After the age of 16 the gland becomes infiltrated with calcareous material which renders it a useful landmark for determining the presence of space-occupying intracranial masses in radiographs.

A small gland located between the cerebral hemispheres of the brain that secretes melatonin.

A small gland found inside your brain. It produces melatonin and regulates your internal clock.

A small gland located in the cerebrum.

An endocrine organ found in the brain. In some animals, it seems to serve as a light-influenced biological clock.

A small gland located deep within in the brain. It is believed to secrete melatonin, and may therefore be part of the body's sleep-regulation apparatus.

an endocrine gland that secretes a hormone that has a general tranquilizing effect on the body and that helps regulate biological rhythms. (199)

Lies below the corpus callosum that produces the hormone melatonin. Melatonin is believed to control the biological rhythms of the body.

pea-sized brain structure, which secretes melatonin and other hormones in mammals

A gland in the brain that secretes the hormone melatonin.

Pineal Gland is a small, cone-shaped organ in the brain of most vertebrates that secretes the hormone melatonin. Also called epiphysis, pineal body; Also called pineal organ .

The pineal gland (also called the pineal body or epiphysis) is a small endocrine gland in the brain. It is located near the center of the brain, between the two hemispheres, tucked in a groove where the two rounded thalamic bodies join. A recent review of the pineal and its secreted hormone, melatonin, is available.