NationMaster - Encyclopedia: Pineal gland

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. ^[1] Image File history File links Illu_endocrine_system. ... Image File history File links Illu_pituitary_pineal_glands. ... Latin is an ancient Indo-European language originally spoken in Latium, the region immediately surrounding Rome. ... Section of an artery For other uses, see Artery (disambiguation). ... The superior cerebellar artery arises near the termination of the basilar. ... Medical Subject Headings (MeSH) is a huge controlled vocabulary (or metadata system) for the purpose of indexing journal articles and books in the life sciences. ... Elseviers logo. ... This article does not cite its references or sources. ... In animals the brain, or encephalon (Greek for in the head), is the control center of the central nervous system, responsible for thought. ... The human brain as viewed from above, showing the cerebral hemispheres. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... Norepinephrine A hormone (from Greek ÏŒÏÎ¼Î® - to set in motion) is a chemical messenger from one cell (or group of cells) to another. ... Melatonin, 5-methoxy-N-acetyltryptamine, is a hormone found in all living creatures from algae[1] to humans, at levels that vary in a diurnal cycle. ...

Location

The pineal gland is a reddish-gray body about the size of a pea (8 mm in humans), located just rostro-dorsal to the superior colliculus and behind and beneath the stria medullaris, between the laterally positioned thalamic bodies. It is part of the epithalamus. Binomial name Pisum sativum L. A pea is the small, edible round green bean which grows in a pod on the leguminous vine Pisum sativum, or in some cases to the immature pods. ... A millimetre (American spelling: millimeter, symbol mm) is an SI unit of length that is equal to one thousandth of a metre. ... The superior colliculus is part of the brain that sits below the thalamus and surrounds the pineal gland in the mesencephalon of vertebrate brains. ... For the computer game developer, see Thalamus Ltd. ... The epithalamus is a dorsal posterior segment of the diencephalon (a segment in the middle of the brain also containing the hypothalamus and the thalamus) which includes the habenula, the stria medullaris and the pineal body. ...

The pineal gland is a midline structure, and is often seen in plain skull X-rays, as it is often calcified. It has been suggested that temporal fenestra be merged into this article or section. ... In the NATO phonetic alphabet, X-ray represents the letter X. An X-ray picture (radiograph) taken by Röntgen An X-ray is a form of electromagnetic radiation with a wavelength approximately in the range of 5 pm to 10 nanometers (corresponding to frequencies in the range 30 PHz... Dystrophic calcification is the mineralization of soft tissue without a systemic mineral imbalance. ...

Structure and composition

The pineal body consists in humans of a lobular parenchyma of pinealocytes surrounded by connective tissue spaces. The glands' surface is covered by a pial capsule. Parenchyma is a term used to describe a bulk of a substance. ... Pinealocytes are the main cells of the pineal gland. ... The pia mater (Latin: tender mother, itself a translation from Arabic) is the delicate innermost layer of the meninges - the membranes surrounding the brain and spinal cord. ...

The pineal gland consists mainly of pinealocytes, but four other cell types have been identified. Drawing of the structure of cork as it appeared under the microscope to Robert Hook from Micrographia which is the origin of the word cell. Cells in culture, stained for keratin (red) and DNA (green). ...

The pineal gland receives a sympathetic innervation from the superior cervical ganglion. However, a parasympathetic innervation from the sphenopalatine and otic ganglia is also present. Further, some nerve fibers penetrate into the pineal gland via the pineal stalk (central innervation). Finally, neurons in the trigeminal ganglion innervates the gland with nerve fibers containing the neuropeptide, PACAP. Human follicles contain a variable quantity of gritty material, called corpora arenacea (or "acervuli", or "brain sand"). Chemical analysis shows that they are composed of calcium phosphate, calcium carbonate, magnesium phosphate, and ammonium phosphate. ^[2]. Recently, calcite deposits have been described as well ^[3]. Pinealocytes are the main cells of the pineal gland. ... Melatonin, 5-methoxy-N-acetyltryptamine, is a hormone found in all living creatures from algae[1] to humans, at levels that vary in a diurnal cycle. ... The introduction to this article provides insufficient context for those unfamiliar with the subject matter. ... A phagocyte is a cell that ingests and destroys foreign matter such as microorganisms or debris via a process known as phagocytosis, in which these cells ingest and kill offending cells by a process analogous to cellular digestion, usually using lysosomes which carry potent enzymes that digests cell components such... Drawing by Santiago RamÃ³n y Cajal of neurons in the pigeon cerebellum. ... Peptides (from the Greek Ï€ÎµÏ€Ï„Î¿Ï‚, digestible), are the family of short molecules formed from the linking, in a defined order, of various Î±-amino acids. ... The word sympathetic means different things in different contexts. ... The superior cervical ganglion, the largest of the cervical ganglia, is placed opposite the second and third cervical vertebrÃ¦. It is of a reddish-gray color, and usually fusiform in shape; sometimes broad and flattened, and occasionally constricted at intervals; it is believed to be formed by the coalescence of... Anatomy and Physiology of the A.N.S. In contrast to the voluntary nervous system, the involuntary or autonomic nervous system is responsible for homeostasis, maintaining a relatively constant internal environment by controlling such involuntary functions as digestion, respiration, and metabolism, and by modulating blood pressure. ... The sphenopalatine artery (nasopalatine artery) passes through the sphenopalatine foramen into the cavity of the nose, at the back part of the superior meatus. ... The trigeminal ganglion (or Gasserian ganglion, or semilunar ganglion) occupies a cavity (Meckels cave) in the dura mater covering the trigeminal impression near the apex of the petrous part of the temporal bone. ... Pituitary adenylate cyclase activating peptide is a peptide similar to vasoactive intestinal peptide. ... There are very few or no other articles that link to this one. ... Calcium phosphate is the name given to a family of minerals containing calcium ions (Ca2+) together with orthophosphates (PO43-), metaphosphates or pyrophosphates (P2O74-) and occasionally hydrogen or hydroxide ions. ... Calcium carbonate is a chemical compound, with chemical formula CaCO3. ... Magnesium phosphate is a phosphate appearing in three forms: Monobasic Dibasic Tribasic Rathbunbasic Chemical formula: Mg3(PO4)2 Various forms have been used as laxatives and antacids. ... Ammonium phosphate. ...

In lower vertebrates

Pinealocytes in lower vertebrate animals have a strong resemblance to the photoreceptor cells of the eye. Some evolutionary biologists believe that the vertebrate pineal cells share a common evolutionary ancestor with retinal cells^[4]. Pinealocytes are the main cells of the pineal gland. ... Classes and Clades See below Male and female Superb Fairy-wren Vertebrates are members of the subphylum Vertebrata (within the phylum Chordata), specifically, those chordates with backbones or spinal columns. ... Animalia redirects here. ... A photoreceptor, or photoreceptor cell, is a specialized type of neuron found in the eyes retina that is capable of phototransduction. ... Eyes are organs of vision that detect light. ... This article is about evolution in biology. ...

In some vertebrates, exposure to light can set off a chain reaction of enzymes, hormones, and neuroreceptors, which may help regulate the animal's circadian rhythm^[5]. Neuraminidase ribbon diagram An enzyme (in Greek en = in and zyme = blend) is a protein, or protein complex, that catalyzes a chemical reaction and also controls the 3D orientation of the catalyzed substrates. ... Hormone is also the NATO reporting name for the Soviet/Russian Kamov Ka-25 military helicopter. ... In biochemistry, a receptor is a protein on the cell membrane or within the cytoplasm or cell nucleus that binds to a specific molecule (a ligand), such as a neurotransmitter, hormone, or other substance, and initiates the cellular response to the ligand. ... A circadian rhythm is a roughly-24-hour cycle in the physiological processes of living beings, including plants, animals, fungi and cyanobacteria. ...

In humans and other mammals, this function is served by the retinohypothalamic system that sets the rhythm within the suprachiasmatic nucleus. Cultural and social interactions produce exposures to artificial light that influence the setting of the suprachiasmatic clock. Evidence for a role for opsin-related light-sensing compounds in the skin of mammals is presently controversial. Research suggests that the pineal gland may serve a magnetoreceptive function in some animals. ^[6] The suprachiasmatic nucleus (SCN) is a nucleus in the hypothalamus situated immediately above the optic chiasm, on either side of the third ventricle. ...

Some early vertebrate fossil skulls have a pineal foramen. This corroborates with the physiology of the modern lamprey, tuatara, and some other vertebrates. In anatomy, a foramen is any opening. ... Lamprey is also the name of a song by Jimmy Buffett and the name of an album by Bettie Serveert. ... Species Sphenodon punctatus (Gray, 1842) Sphenodon guntheri Buller, 1877 Sphenodon diversum (extinct) The tuatara is a reptile of the family Sphenodontidae, endemic to New Zealand. ...

Function

The pineal gland was originally believed to be a "vestigial remnant" of a larger organ (much as the appendix was thought to be a vestigial digestive organ). Researchers at Yale University discovered a hormone which is secreted from the pineal gland, but thus far its function is not completely known. One hormone is Melatonin concerned with pigmentation. Melatonin is a derivative of the amino acid tryptophan, which also has other functions in the Central Nervous System. The production of melatonin by the pineal gland is stimulated by darkness and inhibited by light. ^[7] The retina detects the light, and directly signals and entrains the suprachiasmatic nucleus (SCN). Fibers project from the SCN to the paraventricular nuclei (PVN), which relay the circadian signals to the spinal cord and out via the sympathetic system to superior cervical ganglia (SCG), and from there into the pineal gland. A vestigial organ is an organ whose original function has been lost during evolution. ... In human anatomy, the vermiform appendix (or appendix, pl. ... Phenylalanine is one of the standard amino acids. ... Tryptophan is an amino acid and essential in human nutrition. ... A diagram showing the CNS: 1. ... The suprachiasmatic nucleus (SCN) is a nucleus in the hypothalamus situated immediately above the optic chiasm, on either side of the third ventricle. ... The Spinal cord nested in the vertebral column. ... The superior cervical ganglion, the largest of the cervical ganglia, is placed opposite the second and third cervical vertebrÃ¦. It contains neurons that supply sympathetic innervation to the face. ...

In his book DMT: The Spirit Molecule, Dr. Rick Strassman theorized that the pineal gland may produce the psychedelic chemical DMT [1], but this has not been proven[2]. In 1990, Rick Strassman began the first new human research with psychedelic, or hallucinogenic, drugs in the United States in over 20 years. ... DMT is a three-letter abbreviation (TLA) which may stand for Dimethyltryptamine, an endogenous and hallucinogenic tryptamine Digital Monetary Trust Discrete multitone modulation aka discrete multitone technique Desoxymethyltestosterone Discrete monitor timing (a VESA standard for computer displays) Divalent Metal Transporter gene (related to haemochromatosis) Data Miniaturization Technology Digital Multimedia Technology...

The pineal gland is large in children, but shrinks at puberty. It appears to play a major role in sexual development, hibernation in animals, metabolism, and seasonal breeding. The abundant melatonin levels in children is believed to inhibit sexual development, and pineal tumors have been linked with precocious puberty. When puberty arrives, melatonin production is reduced. Calcification of the pineal gland is typical in adults. Puberty refers to the process of physical changes by which a childs body becomes an adult body capable of reproduction. ... This article is about the process of hibernation in biology. ... Dystrophic calcification is the mineralization of soft tissue without a systemic mineral imbalance. ...

Pineal cytostructure seems to have evolutionary similarities to the retinal cells of chordates. ^[8] Modern birds and reptiles have been found to express the phototransducing pigment melanopsin in the pineal gland. Avian pineal glands are believed to act like the suprachiasmatic nucleus in mammals. ^[9] â€œAvesâ€ redirects here. ... Subclasses Anapsida Diapsida Synonyms Reptilia Laurenti, 1768 Reptiles are tetrapods and amniotes, animals whose embryos are surrounded by an amniotic membrane, and members of the class Sauropsida. ... Visual phototransduction is a process by which light is converted into electrical signals in the rod cells and cone cells of the retina of the eye. ... Natural Ultramarine pigment in powdered form. ... Melanopsin is a photopigment found in specialized ganglion cells of the retina that are involved in the regulation of circadian rhythms and pupillary reflex. ... The suprachiasmatic nucleus (SCN) is a nucleus in the hypothalamus situated immediately above the optic chiasm, on either side of the third ventricle. ... Subclasses Subclass Allotheria* Order Docodonta (extinct) Order Multituberculata (extinct) Order Palaeoryctoides (extinct) Order Triconodonta (extinct) Order Volaticotheria (extinct) Subclass Prototheria Order Monotremata Subclass Theria Infraclass Trituberculata (extinct) Infraclass Metatheria Infraclass Eutheria Mammals are a class of vertebrate animals characterized by the production of milk in females for the nourishment of...

Reports in rodents suggest that the pineal gland may influence the actions of drugs of abuse such as cocaine ^[10] and antidepressants such as fluoxetine (Prozac)^[11]; and contribute to regulation of neuronal vulnerability.^[12] Drug abuse has a wide range of definitions related to taking a psychoactive drug or performance enhancing drug for a non-therapeutic or non-medical effect. ... A recent form of antidepressant medication - Prozac Serotonin-norepinephrine reuptake inhibitor, Venlafaxine An antidepressant, in the most common usage, is a medication taken to alleviate clinical depression or dysthymia (milder depression). ...

Mythologies, cultures and philosophies

The secretory activity of the pineal gland has only relatively recently become understood. To philosophers, its location deep in the brain seemed to indicate its importance. This combination led to its being a "mystery" gland with myth, superstition and metaphysical theories surrounding its perceived function. Plato and Aristotle (right), by Raphael (Stanza della Segnatura, Rome). ...

René Descartes, who dedicated much time to the study of the pineal gland,^[13] called it the "seat of the soul" ^[14], believing it is unique in the anatomy of the human brain in being a structure not duplicated on the right and left sides. This observation is not true, however; under a microscope one finds the pineal gland is divided into two fine hemispheres. Another theory was that the pineal operated as a valve releasing fluids, thus the position taken during deep thought, with the head slightly down meeting the hand, was an allowance for the opening of these 'valves'. RenÃ© Descartes (March 31, 1596 â€“ February 11, 1650), also known as Renatus Cartesius (latinized form), was a highly influential French philosopher, mathematician, scientist, and writer. ... The soul, according to many religious and philosophical traditions, is the self-aware essence unique to a particular living being. ...

The pineal gland is occasionally associated with the sixth chakra (also called Ajna or the third eye chakra in yoga) or sometimes the Seventh (Crown) chakra. It is believed by some to be a dormant organ that can be awakened to enable telepathic communication. This article or section does not adequately cite its references or sources. ... Ajna is the sixth primary chakra according to the Indian Tantric tradition (Shakta). ... 17th century representation of the third eye connection to the higher worlds by alchemist Robert Fludd. ... Yoga (Devanagari: à¤¯à¥‹à¤—) is one of the six schools of Hindu philosophy, focusing on meditation as a path to self-knowledge and liberation. ... Telepathy, from the Greek Ï„á¿†Î»Îµ, tele, remote; and Ï€Î¬Î¸ÎµÎ¹Î±, patheia, to be effected by, describes the hypothetical transfer of information on thoughts or feelings between individuals by means other than the five classical senses. ...

The relevance of the pineal gland to Discordianism, an idiosyncratic religion with roots in California psychedelic culture whose doctrines display great fondness for paradox, is great if not well understood. Discordianism is a modern, chaos-centered religion founded circa 1958â€“1959 by Malaclypse the Younger with the publication of its principal text, the Principia Discordia. ... Official language(s) English Capital Sacramento Largest city Los Angeles Area Ranked 3rd - Total 158,302 sq mi (410,000 kmÂ²) - Width 250 miles (400 km) - Length 770 miles (1,240 km) - % water 4. ... Look up paradox in Wiktionary, the free dictionary. ...

Writers such as Alice Bailey, considered an early proponent of the new age movement, use the pineal-eye as a key element in their spiritual world-view...(see Alice Bailey: "A Treatise on White Magic") Alice A. Bailey (16th June,1880 â€‘ 15th December,1949), writer and lecturer on Neo-Theosophy, was born in England in 1880 as Alice LaTrobe Bateman. ... New Age describes a broad movement characterized by alternative approaches to traditional Western culture. ... Alice A. Bailey (16th June,1880 â€‘ 15th December,1949), writer and lecturer on Neo-Theosophy, was born in England in 1880 as Alice LaTrobe Bateman. ... A Treatise on White Magic by Alice Bailey was first published in 1934 with the subtitle The Way of the Disciple. It is an important esoteric text. ...

The notion of a 'pineal-eye' is also crucial to the philosophy of the seminal French writer Georges Bataille, which is analysed at length by literary scholar Denis Hollier in 'Against Architecture' (1990, trans. Betsy Wing). In this work Hollier discusses how Batailles' uses the concept of a 'pineal-eye' as a reference to a blind-spot in Western rationality. This article or section does not adequately cite its references or sources. ...

Additional images

References

^ Macchi M, Bruce J. "Human pineal physiology and functional significance of melatonin.". Front Neuroendocrinol 25 (3-4): 177-95. PMID 15589268.
^ Bocchi G, Valdre G (1993). "Physical, chemical, and mineralogical characterization of carbonate-hydroxyapatite concretions of the human pineal gland.". J Inorg Biochem 49 (3): 209-20. PMID 8381851.
^ Baconnier S, Lang S, Polomska M, Hilczer B, Berkovic G, Meshulam G (2002). "Calcite microcrystals in the pineal gland of the human brain: first physical and chemical studies.". Bioelectromagnetics 23 (7): 488-95. PMID 12224052.
^ Klein D (2004). "The 2004 Aschoff/Pittendrigh lecture: Theory of the origin of the pineal gland--a tale of conflict and resolution.". J Biol Rhythms 19 (4): 264-79. PMID 15245646.
^ Moore RY, Heller A, Wurtman RJ, Axelrod J. Visual pathway mediating pineal response to environmental light. Science 1967;155(759):220–3. PMID 6015532
^ (Deutschlander et al.,1999)
^ Axelrod J (1970). "The pineal gland.". Endeavour 29 (108): 144-8. PMID 4195878.
^ Klein D (2004). "The 2004 Aschoff/Pittendrigh lecture: Theory of the origin of the pineal gland--a tale of conflict and resolution.". J Biol Rhythms 19 (4): 264-79. PMID 15245646.
^ Natesan A, Geetha L, Zatz M (2002). "Rhythm and soul in the avian pineal.". Cell Tissue Res 309 (1): 35-45. PMID 12111535.
^ Uz T, Akhisaroglu M, Ahmed R, Manev H (2003). "The pineal gland is critical for circadian Period1 expression in the striatum and for circadian cocaine sensitization in mice.". Neuropsychopharmacology 28 (12): 2117-23. PMID 12865893.
^ Uz T, Dimitrijevic N, Akhisaroglu M, Imbesi M, Kurtuncu M, Manev H (2004). "The pineal gland and anxiogenic-like action of fluoxetine in mice.". Neuroreport 15 (4): 691-4. PMID 15094477.
^ Manev H, Uz T, Kharlamov A, Joo J (1996). "Increased brain damage after stroke or excitotoxic seizures in melatonin-deficient rats.". FASEB J 10 (13): 1546-51. PMID 8940301.
^ Descartes and the Pineal Gland (Stanford Encyclopedia of Philosophy)
^ Descartes R. Treatise of Man. New York: Prometheus Books; 2003. ISBN 1-59102-090-5

The Stanford Encyclopedia of Philosophy (hereafter SEP) is a free online encyclopedia of philosophy run and maintained by Stanford University. ...

External links

Categories: Glands | Endocrine system | Head and neck The subthalamus, or ventral thalamus, is part of the diencephalon. ... Coronal slices of human brain showing the basal ganglia, globus pallidus: external segment (GPe), subthalamic nucleus (STN), globus pallidus: internal segment (GPi), and substantia nigra (SN). ... The zona incerta is a small region of gray matter that is part of the subthalamus. ... The thalamic fasciculus is a component of the subthalamus. ... The lenticular fasciculus is a component of the subthalamus. ... For the computer game developer, see Thalamus Ltd. ... Nuclear groups of the thalamus include: anterior nuclear group anteroventral nucleus anterodorsal nucleus anteromedial nucleus medial nuclear group dorsomedial nucleus parvocellular part magnocellular part midline nuclear group paratenial nucleus parventricular nucleus reuniens nucleus rhombodoidal nucleus intralaminar nuclear group centromedian nucleus parafascicular nucleus paracentral nucleus central lateral nucleus central medial nucleus... The ventral nuclear group is a collection of nuclei on the ventral side of the thalamus. ... The Ventral anterior nucleus receives neuronal inputs from the basal ganglia which includes the substantia nigra and the globus pallidus. ... The ventral lateral nucleus receives neuronal inputs from the basal ganglia which includes the substantia nigra and the globus pallidus. ... The ventral posterior nucleus is the somato-sensory relay nucleus in thalamus of the brain. ... The ventral posteromedial nucleus (VPM) is a nucleus of the thalamus which projects to the postcentral gyrus and receives the solitary tract. ... The ventral posterolateral nucleus (VPL) is a nucleus of the thalamus which projects to the postcentral gyrus and receives information from the medial lemniscus. ... The medial dorsal nucleus is a a large nucleus in the thalamus. ... The anterior nuclei of thalamus (or anterior nuclear group) is a region of the thalamus which projects to the cingulate gyrus. ... The lateral nuclear group is a collection of nuclei on the lateral side of the thalamus. ... The pulvinar is the caudal-most nucleus of the thalamus that is conventionally divided into oral, inferior, lateral, and medial subnuclei. ... The intralaminar nucleus is a nucleus of the thalamus which contains the following nuclei: central lateral centromedian (or central medial) paracentral parafascicular Some sources also include a central dorsal nucleus. ... In anatomy, the centromedian nucleus, also known as the centrum medianum, (CM or Cm-Pf) is a part of the intralaminar nucleus (ILN) of the thalamus. ... The midline nuclear group (or midline thalamic nuclei) a region of the thalamus consisting of the following nuclei: paraventricular nucleus of thalamus (nucleus paraventricularis thalami) - not to be confused with paraventricular nucleus of hypothalamus paratenial nucleus (nucleus parataenialis) reuniens nucleus (nucleus reuniens) rhomboidal nucleus (nucleus commissuralis rhomboidalis) subfascicular nucleus (nucleus... The thalamic reticular nucleus is part of the ventral thalamus that forms a capsule around the thalamus laterally. ... The metathalamus is a composite structure of the thalamus, consisting of the medial geniculate nucleus and the lateral geniculate nucleus. ... The medial geniculate nucleus is a nucleus of the thalamus that acts as a relay for auditory information. ... Grays FIG. 719â€“ Hind- and mid-brains; postero-lateral view. ... The medial surface of the thalamus constitutes the upper part of the lateral wall of the third ventricle, and is connected to the corresponding surface of the opposite thalamus by a flattened gray band, the Interthalamic adhesion (massa intermedia, middle commissure, gray commissure). ... The third ventricle is one of the four connected fluid-filled cavities within the human brain. ... At the junction of the floor and anterior wall of the third ventricle, immediately above the optic chiasma, the ventricle presents a small angular recess or diverticulum, the optic recess (or supraoptic recess). ... The floor of the third ventricle is prolonged downward as a funnel-shaped recess, the infundibular recess, into the infundibulum, and to the apex of the latter the hypophysis is attached. ... The suprapineal recess (Latin: recessus suprapineale)is an anatomical structure in the ventricular system of the brain. ... The pineal recess is a small recess of the third ventricle which projects into the stalk of the pineal body. ... The upper and lower portions of the lateral wall of the third ventricle correspond to the alar lamina and basal lamina respectively of the lateral wall of the fore-brain vesicle and are separated from each other by a furrow, the hypothalamic sulcus (sulcus of Monro), which extends from the... The interventricular foramen (aka the foramen of Monro) joins the lateral ventricles of the brain with the anterior third ventricle. ... Visual pathway with optic chiasm circled The optic chiasm (from the Greek Ï‡Î»Î±Î¶ÎµÎ¹Î½ to mark with an X, after the letter Î§ chi) is the part of the brain where the optic nerves partially cross, those parts of the right eye which see things on the right side being connected to the... The Subfornical organ is one of the circumventricular organs of the brain and is involved in thirst-regulation. ... The mammillothalamic fasciculus (mammillothalamic tract, thalamomammillary fasciculus, bundle of Vicq dâ€™Azyr) arises from cells in both the medial and lateral nuclei of the mammillary body and by fibers that are directly continued from the fornix. ...

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