Editing Spleen (section)

== Structure ==
In humans, the spleen is underneath the left part of the [[Thoracic diaphragm|diaphragm]], and has a smooth, convex surface that faces the diaphragm. It is underneath the ninth, tenth, and eleventh ribs. The other side of the spleen is divided by a ridge into two regions: an anterior gastric portion, and a posterior [[renal]] portion. The gastric surface is directed forward, upward, and toward the middle, is broad and concave, and is in contact with the posterior wall of the [[stomach]]. Below this it is in contact with the tail of the [[pancreas]]. The renal surface is directed medialward and downward. It is somewhat flattened, considerably narrower than the gastric surface, and is in relation with the upper part of the anterior surface of the left kidney and occasionally with the left [[adrenal gland]].

There are four ligaments attached to the spleen: [[gastrosplenic ligament]], [[splenorenal ligament]], [[colicosplenic ligament]], and [[phrenocolic ligament]].<ref>{{Cite journal |last1=Ostermann |first1=P. A. W. |last2=Schreiber |first2=H. W. |last3=Lierse |first3=W. |date=September 1987 |title=Der Bandapparat der Milz und seine Bedeutung bei chirurgischen Eingriffen |url=http://link.springer.com/10.1007/BF01259432 |journal=Langenbeck's Archiv für Chirurgie |language=de |volume=371 |issue=3 |pages=207–216 |doi=10.1007/BF01259432 |pmid=3683035 |s2cid=35213355 |issn=0023-8236}}</ref>

=== Measurements ===
{| class="wikitable" style="float:right;"
|+ 90% [[confidence interval]] of spleen length by [[abdominal ultrasonography]] by height of the person<ref name="ChowLuxembourg2016">{{cite journal|last1=Chow|first1=Kai Uwe|last2=Luxembourg|first2=Beate|last3=Seifried|first3=Erhard|last4=Bonig|first4=Halvard|title=Spleen Size Is Significantly Influenced by Body Height and Sex: Establishment of Normal Values for Spleen Size at US with a Cohort of 1200 Healthy Individuals|journal=Radiology|volume=279|issue=1|year=2016|pages=306–13|issn=0033-8419|doi=10.1148/radiol.2015150887|pmid=26509293|doi-access=}}</ref>
|-
!rowspan=2| Height !!colspan=2| Spleen length
|-
! Women !! Men
|-
| 155–159&nbsp;cm || 6.4–12&nbsp;cm || 
|-
| 160–164&nbsp;cm || 7.4–12.2&nbsp;cm || 8.9–11.3&nbsp;cm
|-
| 165–169&nbsp;cm || 7.5–11.9&nbsp;cm || 8.5–12.5&nbsp;cm
|-
| 170–174&nbsp;cm || 8.3–13.0&nbsp;cm || 8.6–13.1&nbsp;cm
|-
| 175–179&nbsp;cm || 8.1–12.3&nbsp;cm || 8.6–13.4&nbsp;cm
|-
| 180–184&nbsp;cm ||  || 9.3–13.4&nbsp;cm
|-
| 185–189&nbsp;cm ||  || 9.3–13.6&nbsp;cm
|-
| 190–194&nbsp;cm ||  || 9.7–14.3&nbsp;cm
|-
| 195–199&nbsp;cm ||  || 10.2–14.4&nbsp;cm
|}

The spleen, in healthy adult humans, is approximately {{convert|7|to|14|cm|in|frac=2}} in length. It weighs between {{cvt|1|oz|g}} and {{cvt|8|oz|g}} (standard [[reference range]]),<ref name="MolinaDiMaio2012">{{cite journal|last1=Molina|first1=D. Kimberley|last2=DiMaio|first2=Vincent J.M.|title=Normal Organ Weights in Men|journal=The American Journal of Forensic Medicine and Pathology|volume=33|issue=4|year=2012|pages=368–372|issn=0195-7910|doi=10.1097/PAF.0b013e31823d29ad|pmid=22182984|s2cid=32174574}}</ref> correlating mainly to height, body weight and degree of acute congestion but not to sex or age.<ref name="Sprogøe-JakobsenSprogøe-Jakobsen1997">{{cite journal|last1=Sprogøe-Jakobsen|first1=Susan|last2=Sprogøe-Jakobsen|first2=Ulrik|title=The weight of the normal spleen|journal=Forensic Science International|volume=88|issue=3|year=1997|pages=215–223|issn=0379-0738|doi=10.1016/S0379-0738(97)00103-5|pmid=9291593}}</ref>

<gallery>
File:Spleen ultrasound.jpg|Spleen seen on [[abdominal ultrasonography]]
File:Maximum length of spleen on ultrasonography.jpg|Maximum length of spleen on [[abdominal ultrasonography]]
File:Gray1226.png|Back of lumbar region, showing surface markings for kidneys, ureters, and spleen
File:Gray1217.png|Side of thorax, showing surface markings for bones, lungs (purple), pleura (blue), and spleen (green)
</gallery>

=== Blood supply ===
[[File:Gray1188.png|200px|thumb|Visceral surface of the spleen]]
Near the middle of the spleen is a long fissure, the [[hilum (anatomy)|hilum]], which is the point of attachment for the [[gastrosplenic ligament]] and the point of insertion for the [[splenic artery]] and [[splenic vein]]. There are other openings present for [[lymphatic vessel]]s and [[nerve]]s. In addition to the splenic artery, collateral blood supply is provided by the adjacent short gastric arteries.<ref>{{cite journal | url=https://pubmed.ncbi.nlm.nih.gov/6730702/|title=The collateral arterial network of the spleen following ligation of the splenic artery in traumatic rupture of the spleen; an arteriographic study|date=1984 |pmid=6730702 |last1=Keramidas |first1=D. C. |last2=Kelekis |first2=D. |last3=Dolatzas |first3=T. |last4=Aivazoglou |first4=T. |last5=Voyatzis |first5=N. |journal=Zeitschrift für Kinderchirurgie |volume=39 |issue=1 |pages=50–51 |doi=10.1055/s-2008-1044169 |s2cid=29302459 }}</ref>

Like the [[thymus]], the spleen possesses only [[efferent lymphatic vessels]]. The spleen is part of the [[lymphatic system]]. Both the [[short gastric arteries]] and the splenic artery supply it with blood.<ref>{{Cite book
| publisher = Lippincott Williams & Wilkins
| isbn = 978-0-7817-7076-7
| last = Blackbourne
| first = Lorne H
| title = Surgical recall
| year = 2008
| page = [https://archive.org/details/surgicalrecall00blac/page/259 259]
| url-access = registration
| url = https://archive.org/details/surgicalrecall00blac/page/259
}}</ref>

The [[germinal center]]s are supplied by [[arteriole]]s called ''penicilliary radicles''.<ref>{{cite web|url=http://medical-dictionary.thefreedictionary.com/penicilliary+radicles |title=Penicilliary radicles |publisher=Medical-dictionary.thefreedictionary.com |access-date=2011-04-03}}</ref>

=== Nerve supply ===
The spleen is innervated by the [[splenic plexus]], which connects a branch of the [[celiac ganglia]] to the [[vagus nerve]].

The underlying [[Central nervous system|central nervous]] processes coordinating the spleen's function seem to be embedded into the [[Hypothalamic–pituitary–adrenal axis|hypothalamic-pituitary-adrenal-axis]], and the [[brainstem]], especially the [[subfornical organ]].<ref>{{Cite journal|last1=Lori|first1=Andrea|last2=Perrotta|first2=Marialuisa|last3=Lembo|first3=Giuseppe|last4=Carnevale|first4=Daniela|date=2017-06-07|title=The Spleen: A Hub Connecting Nervous and Immune Systems in Cardiovascular and Metabolic Diseases|journal=International Journal of Molecular Sciences|volume=18|issue=6|page=1216|doi=10.3390/ijms18061216|issn=1422-0067|pmc=5486039|pmid=28590409|doi-access=free}}</ref>

=== Development ===
The spleen is unique in respect to its development within the [[Human gastrointestinal tract|gut]]. While most of the gut [[organ (anatomy)|organs]] are [[endodermally]] derived, the spleen is derived from [[Mesenchyme|mesenchymal tissue]].<ref>{{cite journal | last= Vellguth | first=Swantje |author2=Brita von Gaudecker |author3=Hans-Konrad Müller-Hermelink | title=The development of the human spleen | journal=[[Cell and Tissue Research]] | volume=242 | issue=3 | pages=579–92 | doi=10.1007/BF00225424 | pmid=4075378 | year= 1985 | s2cid=19864892 }}</ref> Specifically, the spleen forms within, and from, the [[dorsal mesentery]]. However, it still shares the same blood supply—the [[celiac trunk]]—as the [[foregut]] organs.