Medical expert of the article
New publications
Pineal body (epiphysis)
Last reviewed: 23.04.2024
All iLive content is medically reviewed or fact checked to ensure as much factual accuracy as possible.
We have strict sourcing guidelines and only link to reputable media sites, academic research institutions and, whenever possible, medically peer reviewed studies. Note that the numbers in parentheses ([1], [2], etc.) are clickable links to these studies.
If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please select it and press Ctrl + Enter.
The pineal body (pineal gland, epiphysis of the brain, corpus pineale, s.glandula pinealis, s.epiphisis cerebri) refers to the epithelamus of the diencephalon and is located in a shallow furrow that separates the upper mounds of the midbrain roof. From the anterior end of the pineal body to the medial surface of the right and left thalamuses (visual hillocks) are leashes (habenulae). The shape of the pineal body is often ovoid, less often spherical or conical. The mass of the pineal body in an adult is about 0.2 g, the length is 8-15 mm, the width is 6-10 m, the thickness is 4-6 mm. At the base of the pineal body, facing the cavity of the third ventricle, there is a small pineal depression.
Outside, the pineal body is covered with a connective tissue capsule containing a large number of blood capillaries anastomosing with each other. From the capsule inside the organ penetrate connective tissue trabeculae, dividing the parenchyma of the pineal body into lobules. Cellular elements of the parenchyma are the specialized glandular cells contained in a large number - pinealocytes (pineocytes) and in smaller - glial cells (gliocytes). In the pineal body, in adults and especially in old age, there are often bizarre forms of deposits - "sandy bodies" (brain sand). These deposits give the pineal body a certain similarity to the mulberry berry or spruce cone, which explains its name.
The endocrine role of the pineal body is that its cells secrete substances that inhibit the activity of the pituitary gland until the onset of puberty and participate in the fine regulation of almost all metabolic species.
Development of the pineal body
The pineal body develops as an unpaired protrusion of the roof of the future third ventricle of the brain. Cells of this outgrowth form a compact cell mass into which the mesoderm grows, which subsequently forms the stroma of the pineal body. The latter, together with the blood vessels, divides the parenchyma of the organ into lobules.
Vessels and nerves of the pineal body
Blood supply of the pineal body is carried out by the branches of the posterior cerebral and upper cerebellar arteries. The veins of the pineal body flow into the large vein of the brain or into its tributaries. Sympathetic nerve fibers penetrate the tissues of the organ together with the vessels.
Age features of the pineal body
The average mass of the pineal body during the first year of life increases from 7 to 100 mg. By the age of 10, the weight of the organ is doubled and, in the following, does not change much. Due to the fact that in different periods of adulthood and especially often in the elderly, cysts and deposits of brain sand can appear in the pineal body, its dimensions and mass may be much larger than the indicated average figures.
[10],