pineal body

views updated May 09 2018

pineal body (epiphysis) In vertebrates other than humans, an outgrowth of the fore brain that secretes hormones affecting reproductive behaviour. In mammals that have a regular oestrus cycle its secretion of melatonin inhibits development of the gonads; the pineal may have a similar function in human children.

pineal body

views updated May 14 2018

pineal body (pineal gland) Small gland attached to the under-surface of the vertebrate brain. In human beings, it has an endocrine function, secreting the hormone melatonin, which is involved in daily rhythms. See also endocrine system