CZ:Featured article/Current: Difference between revisions

From Citizendium
Jump to navigation Jump to search
imported>Chunbum Park
(Thylakoid)
imported>Chunbum Park
(→‎Thylakoid: Oxytocin)
Line 1: Line 1:
== '''[[Thylakoid]]''' ==
== '''[[Oxytocin]]''' ==
----
----
{{Image|Chloroplast.png|right|300px|Schematic of a chloroplast: 1. outer membrane; 2. intermembrane space; 3. inner membrane (1+2+3: envelope); 4. [stroma (aqueous fluid); 5. thylakoid lumen (inside of thylakoid); 6. thylakoid membrane; 7. granum (stack of thylakoids); 8. thylakoid (lamella); 9. Starch; 10. Ribosome; 11. plastidial DNA; 12. plastoglobule (drop of lipids).}}
'''Oxytocin''' (Greek: "quick birth") is a [[mammal]]ian [[hormone]] that is secreted into the bloodstream from the [[posterior pituitary]] gland, and that is also released into the [[brain]], where it has effects on social behaviors. In pregnant women, it is secreted into the blood during labor in response to distention of the [[cervix]] and it stimulates contractions of the [[uterus]] to facilitate [[childbirth|birth]]. During [[lactation]], oxytocin is secreted in response to stimulation of the [[nipple]]s by the sucking of the infant, and it stimulates milk let-down in the [[mammary gland]]. Oxytocin is also secreted during [[orgasm]] in both sexes; in men it facilitates movement of [[sperm]]. In the brain, it is involved in social recognition, bonding, sexual arousal, reproductive behaviors and appetite regulation, and might be involved in the formation of trust between people. In some species, including rats, oxytocin also promotes sodium excretion ([[natriuresis]]) and inhibits [[sodium appetite]].<ref>Lee HJ ''et al.'' (2009) Oxytocin: the great facilitator of life.
Inside [[plant]] [[Cell (biology)|cells]] and other [[Eukaryote|eukaryotic]] cells that perform [[photosynthesis]], tiny, [[bacteria]]-sized [[organelle]]s, called [[chloroplast]]s, contain, within the inner membrane of their dual membrane structure, an extensive system of single-membrane-bound flattened sacs called '''thylakoids''', their interior spaces (lumens) interconnected, their membranes housing the pigment molecules that absorb the [[energy]] of [[photon]]s of particular frequencies emitted by the sun, an event that initiates the physico-chemical sequence of steps culminating in the products of photosynthesis.<ref>[http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/C/Chloroplasts.html Chloroplasts]. | Additional information about chloroplasts and thylakoids.</ref>  A semifluid matrix within the chloroplasts, called the [[stroma]], bathes the thylakoids. The flattened thylakoid sacs consist of clustered stacks, called [[granum|grana]], their lumens interconnected by extensions, called 'stromal thylakoids', or [[lamellae]].<ref name=mustardytpc2008>Mustardy L, Buttle K, Steinbach G, Garab G. (2008) [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2590735/?tool=pmcentrez The three-dimensional network of the thylakoid membranes in plants: quasihelical model of the granum-stroma assembly]. ''Plant Cell'' 20:2552-7.
''Prog Neurobiol'' 88:127-51. Review. PMID 19482229</ref><ref>Neumann ID (2008) Brain oxytocin: a key regulator of emotional and social behaviours in both females and males ''J Neuroendocrinol'' 20:858-65. Review.
*<font face=Gill Sans MT">View also the supplementary figures and video linked in this paper.</font></ref> [See accompanying illustration at right.]
PMID 18601710</ref><ref>Arthur P ''et al.'' (2007) Oxytocin and parturition: a role for increased myometrial calcium and calcium sensitization? ''Front Biosci''  12:619-33. Review. PMID 17127323</ref>
<ref>Caldwell HK, Young WS III (2006) Oxytocin and vasopressin: genetics and behavioral implications. In Lim R. (ed.) ''Handbook of Neurochemistry and Molecular Neurobiology'' 3rd edition, Springer, New York, pp. 573-607. [http://refworks.springer.com/mrw/fileadmin/pdf/Neurochemistry/0387303480C25.PDF 320kb PDF]</ref>


''[[Thylakoid|.... (read more)]]''
''[[Oxytocin|.... (read more)]]''


{| class="wikitable collapsible collapsed" style="width: 90%; float: center; margin: 0.5em 1em 0.8em 0px;"
{| class="wikitable collapsible collapsed" style="width: 90%; float: center; margin: 0.5em 1em 0.8em 0px;"
|-
|-
! style="text-align: center;" | &nbsp;[[Thylakoid#References|notes]]
! style="text-align: center;" | &nbsp;[[Oxytocin#References|notes]]
|-
|-
|
|
{{reflist|2}}
{{reflist|2}}
|}
|}

Revision as of 07:04, 16 February 2014

Oxytocin

Oxytocin (Greek: "quick birth") is a mammalian hormone that is secreted into the bloodstream from the posterior pituitary gland, and that is also released into the brain, where it has effects on social behaviors. In pregnant women, it is secreted into the blood during labor in response to distention of the cervix and it stimulates contractions of the uterus to facilitate birth. During lactation, oxytocin is secreted in response to stimulation of the nipples by the sucking of the infant, and it stimulates milk let-down in the mammary gland. Oxytocin is also secreted during orgasm in both sexes; in men it facilitates movement of sperm. In the brain, it is involved in social recognition, bonding, sexual arousal, reproductive behaviors and appetite regulation, and might be involved in the formation of trust between people. In some species, including rats, oxytocin also promotes sodium excretion (natriuresis) and inhibits sodium appetite.[1][2][3] [4]

.... (read more)

Retrieved from "https://citizendium.org/wiki/index.php?title=CZ:Featured_article/Current&oldid=829538"