Kelenjar pineal: Perbedaan antara revisi
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Kelenjar pineal adalah struktur berbentuk garis tengah seperti buah pohon cemara <ref>{{cite web|last=Bowen|first=R.|title=The Pineal Gland and Melatonin|url=http://www.vivo.colostate.edu/hbooks/pathphys/endocrine/otherendo/pineal.html|accessdate=14 October 2011}}</ref> , dan sering terlihat di [[tengkorak]] [[X-ray]], seperti yang sering [[kalsifikasi]].
==Structure and composition==
[[Image:Pineal.jpg|thumb|Pineal gland parenchyma with calcifications.]]
[[Image:Pineal gland - very high mag.jpg|thumb|150px|[[Micrograph]] of a normal pineal gland – very high magnification.]]
[[Image:Pineal gland - intermed mag.jpg|thumb|150px|[[Micrograph]] of a normal pineal gland – intermediate magnification.]]
The pineal body consists in humans of a lobular [[parenchyma]] of [[pinealocytes]] surrounded by [[connective tissue]] spaces. The gland's surface is covered by a [[pial]] capsule.
The pineal gland consists mainly of pinealocytes, but four other [[cell (biology)|cell]] types have been identified. As it is quite cellular (in relation to the cortex and white matter) it may be mistaken for a [[neoplasm]].<ref>{{cite journal |author=Kleinschmidt-DeMasters BK, Prayson RA |title=An algorithmic approach to the brain biopsy—part I |journal=Arch. Pathol. Lab. Med. |volume=130 |issue=11 |pages=1630–8 |date=November 2006 |pmid=17076524 |doi=10.1043/1543-2165(2006)130[1630:AAATTB]2.0.CO;2 |year=2006}}</ref>
{| class="wikitable" border="1"
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| '''Cell type''' || '''Description'''
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| [[Pinealocyte]]s || The pinealocytes consist of a cell body with 4–6 processes emerging. They produce and secrete [[melatonin]]. The pinealocytes can be stained by special silver impregnation methods. Their cytoplasm is lightly basophilic. With special stains, pinealocytes exhibit lengthy, branched cytoplasmic processes which extend to the connective septa and its blood vessels.
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| [[Interstitial cell]]s || Interstitial cells are located between the pinealocytes. They have elongated nuclei and a cytoplasm which is stained darker than that of the pinealocytes.
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| [[Perivascular]] [[phagocyte]] || Many capillaries are present in the gland, and perivascular phagocytes are located close to these blood vessels. The perivascular phagocytes are antigen presenting cells.
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| pineal [[neuron]]s || In higher vertebrates neurons are located in the pineal gland. However, these are not present in rodents.
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| [[peptide]]rgic neuron-like cells || In some species, neuronal-like peptidergic cells are present. These cells might have a paracrine regulatory function.
|}
The pineal gland receives a [[sympathetic nervous system|sympathetic]] innervation from the [[superior cervical ganglion]]. However, a [[parasympathetic]] innervation from the [[sphenopalatine]] and [[otic ganglion|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]] innervate 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]].<ref>{{cite journal |author=Bocchi G, Valdre G |title=Physical, chemical, and mineralogical characterization of carbonate-hydroxyapatite concretions of the human pineal gland |journal=J Inorg Biochem |volume=49 |issue=3 |pages=209–20 |year=1993 |pmid=8381851 |doi=10.1016/0162-0134(93)80006-U}}</ref> In 2002, deposits of the [[calcite]] form of calcium carbonate were described.<ref>{{cite journal |author=Baconnier S, Lang S, Polomska M, Hilczer B, Berkovic G, Meshulam G |title=Calcite microcrystals in the pineal gland of the human brain: first physical and chemical studies |journal=Bioelectromagnetics |volume=23 |issue=7 |pages=488–95 |year=2002 |pmid=12224052 |doi=10.1002/bem.10053}}</ref> Calcium, phosphorus<ref>{{cite web |url= http://www.ingentaconnect.com/content/hum/bter/2007/00000119/00000002/art00004 |title=IngentaConnect High Accumulation of Calcium and Phosphorus in the Pineal Bodies |publisher=Ingentaconnect.com |date= 2006-06-16 |accessdate=2009-07-06}}</ref> and [[fluoride]]<ref name="fluoride"/> deposits in the pineal gland have been linked with aging.
== Referensi ==
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