Editing Seminal vesicles (section)

==Structure==
The human seminal vesicles are a pair of glands in males that are positioned below the [[urinary bladder]] and at the end of the [[vasa deferentia]], where they enter the [[prostate]]. Each vesicle is a coiled and folded tube, with occasional outpouchings termed diverticula in its wall.<ref name=HistologyText>{{cite book|title=Histology: A Text and Atlas, with Correlated Cell and Molecular Biology |edition=6th |year=2010 |author1=Michael H. Ross |author2=Wojciech Pawlina |chapter-url=https://www.inkling.com/read/histology-michael-ross-and-wojciech-pawlina-6th/chapter-22/plate-91-seminal-vesicle |chapter=Male Reproductive System |page=828 |publisher=Wolters Kluwer/Lippincott Williams & Wilkins Health |isbn=978-0781772006}}</ref> The lower part of the tube ends as a straight tube called the ''excretory duct'', which joins with the vas deferens of that side of the body to form an [[ejaculatory duct]]. The ejaculatory ducts pass through the prostate gland before opening separately into the [[Seminal colliculus|verumontanum]] of the prostatic [[urethra]].<ref name="HistologyText" /> The vesicles are between 5–10&nbsp;cm in size, 3–5&nbsp;cm in diameter, and have a volume of around 13 mL.<ref name="Grays2016">{{Cite book|url=https://www.worldcat.org/oclc/920806541|title=Gray's anatomy : the anatomical basis of clinical practice|year=2016|isbn=9780702052309|editor=Standring, Susan|edition=41st|location=Philadelphia|pages=1279–1280|section=Seminal vesicles|oclc=920806541}}</ref>

<!-- Blood, nerve and lymphatic supply -->The vesicles receive blood supply from the vesiculodeferential artery, and also from the [[inferior vesical artery]]. The [[vesiculodeferential artery]] arises from the [[umbilical arteries]], which branch directly from the [[internal iliac arteries]].<ref name="Grays2016" /> Blood is drained into the [[vesiculodeferential vein]]s and the inferior vesical plexus, which drain into the [[internal iliac vein]]s.<ref name="Grays2016" /> [[Lymphatic Drainage|Lymphatic drainage]] occurs along the venous routes, draining into the [[Internal iliac lymph nodes|internal iliac nodes]].<ref name="Grays2016" />

<!-- Surrounding structures -->The vesicles lie behind the bladder at the end of the vasa deferentia. They lie in the space between the bladder and the [[rectum]]; the bladder and prostate lie in front, the tip of the [[ureter]] as it enters the bladder above, and [[Rectoprostatic fascia|Denonvilliers' fascia]] and the rectum behind.<ref name="Grays2016" />

===Development===
{{Further|Development of the urinary system}}
In the developing [[embryo]], at the hind end lies a [[Cloaca (embryology)|cloaca]]. This, over the fourth to the seventh week, divides into a [[urogenital sinus]] and the beginnings of the [[anal canal]], with a wall forming between these two inpouchings called the [[urorectal septum]].<ref name=Langman2019>{{cite book |last1=Sadley |first1=TW |title=Langman's medical embryology |date=2019|location=Philadelphia|publisher=Wolters Kluwer |isbn=9781496383907 |edition=14th|section=Genital ducts|pages=271–5}}</ref> Two ducts form next to each other that connect to the urogenital sinus; the [[mesonephric duct]] and the [[paramesonephric duct]], which go on to form the [[reproductive tract]]s of the male and female respectively.<ref name=Langman2019 />

In the male, under the influence of [[testosterone]], the mesonephric ducts proliferate, forming the [[epididymis]], [[ductus deferens]] and, via a small outpouching near the developing prostate, the seminal vesicles.<ref name=Langman2019 /> [[Sertoli cell]]s secrete [[anti-Müllerian hormone]], which causes the paramesonephric ducts to regress.<ref name=Langman2019 />

The development and maintenance of the seminal vesicles, as well as their secretion and size/weight, are highly dependent on [[androgen]]s.<ref name="FeyHeni2012">{{cite book|author1=B. Fey|author2=F. Heni|author3=A. Kuntz|author4=D. F. McDonald|author5=L. Quenu|author6=L. G. jr. Wesson|author7= C. Wilson|title=Physiologie und Pathologische Physiologie / Physiology and Pathological Physiology / Physiologie Normale et Pathologique|url=https://books.google.com/books?id=X8DyCAAAQBAJ&pg=PA611|date=6 December 2012|publisher=Springer Science & Business Media|isbn=978-3-642-46018-0|pages=611–}}</ref><ref name="pmid11753468">{{cite journal | vauthors = Gonzales GF | title = Function of seminal vesicles and their role on male fertility | journal = Asian J. Androl. | volume = 3 | issue = 4 | pages = 251–8 | year = 2001 | pmid = 11753468 }}</ref> The seminal vesicles contain [[5α-reductase]], which metabolizes testosterone into its much more potent [[metabolite]], [[dihydrotestosterone]] (DHT).<ref name="pmid11753468" /> The seminal vesicles have also been found to contain [[luteinizing hormone receptor]]s, and hence may also be regulated by the ligand of this receptor, [[luteinizing hormone]].<ref name="pmid11753468" />

===Microanatomy===
[[File:Histology of seminal vesicle glands on H&E stain.jpg|thumb|Histology of seminal vesicle glands on H&E stain. They may mimic prostatic adenocarcinoma by crowded glands with enlarged hyperchromatic and irregular nuclei, but will have inconspicuous nucleoli and coarse refractile golden brown lipofuscin granules.<ref>Image by Mikael Häggström, MD. Reference for findings: {{cite web|url=https://www.pathologyoutlines.com/topic/prostateseminalves.html|title=Anatomy & histology-seminal vesicles / ejaculatory duct|website=Pathology Outlines|author=Faryal Shoaib, M.D., Chinedum Okafor, M.D., Y. Albert Yeh, M.D., Ph.D.}} Last staff update: 20 November 2023</ref>]]
The inner lining of the seminal vesicles (the [[epithelium]]) is made of a lining of [[stratified columnar epithelia|interspersed column-shaped]] and [[cuboidal epithelium|cube-shaped]] cells.<ref name=Wheaters2013 /> There are varying descriptions of the lining as being [[Pseudostratified columnar epithelium|pseudostratified]] and consisting of column-shaped cells only.<ref name=Smiths2019>{{cite book |last1=Arthur D. Smith (Editor), Glenn Preminger (Editor), Gopal H. Badlani (Editor), Louis R. Kavoussi (Editor)|title=Smith's textbook of endourology|year=2019 |publisher=John Wiley & Sons Ltd |isbn=9781119245193 |edition=4th|chapter=112. Laparoscopic and Robotic Surgery of the Seminal Vessels|pages=1292–1298}}</ref> When [[Histology|viewed under a microscope]], the cells are seen to have large bubbles in their interior. This is because their interior, called [[cytoplasm]], contains lipid droplets involved in secretion during ejaculation.<ref name=Wheaters2013>{{cite book |last1=Young |first1=Barbara |last2=O'Dowd |first2=Geraldine |last3=Woodford |first3=Phillip |title=Wheater's functional histology: a text and colour atlas.|publisher=Elsevier |location=Philadelphia |date=2013|isbn=9780702047473 |edition=6th|chapter=Male reproductive system|page=346}}</ref> The tissue of the seminal vesicles is full of glands, spaced irregularly.<ref name=Wheaters2013 /> As well as glands, the seminal vesicles contain [[smooth muscle]] and [[connective tissue]].<ref name=Wheaters2013 /> This fibrous and muscular tissue surrounds the glands, helping to expel their contents.<ref name="Grays2016" /> The outer surface of the glands is covered in [[peritoneum]].<ref name="Grays2016" />

<gallery>
Image:Seminal vesicle low mag.jpg|Low magnification [[micrograph]] of seminal vesicle. H&E stain.
Image:Seminal vesicle high mag.jpg|High magnification micrograph of seminal vesicle. H&E stain.
</gallery>