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==Overview==

In [[anatomy]], the term '''ligament''' is used to denote three different types of structures: <ref>{{eMedicineDictionary|ligament}}</ref>
# Fibrous [[tissue]] that connects [[bone]]s to other bones. They are sometimes called "articular ligaments"<ref>{{Dorlands|l_09|12488504}}</ref>, "fibrous ligaments", or "true ligaments".
# A fold of [[peritoneum]] or other membrane
# The remnants of a tubular structure from the [[fetus|fetal]] period of life

The first meaning is most commonly what is meant by the term "ligament". After briefly discussing the other two types of ligaments, the remainder of this article will focus upon the first type.

==Peritoneal ligaments==
Certain folds of [[peritoneum]] are referred to as ''ligaments''. 

Examples include:

* The [[hepatoduodenal ligament]] surrounds the [[hepatic portal vein]] and other vessels as they travel from the [[duodenum]] to the [[liver]].  
* The [[broad ligament of the uterus]] is also a fold of peritoneum.
* The [[suspensory ligament of the ovary]]

==Fetal remnant ligaments==
Certain tubular structures from the fetal period are referred to as ''ligaments'' after they close up and turn into cord-like structures:

{| class="wikitable"
| '''Fetal''' || '''Adult'''
 |- 
 |[[ductus arteriosus]] || [[ligamentum arteriosum]]
 |- 
 | extra-[[hepatic]] portion of the fetal left [[umbilical vein]] || [[ligamentum teres hepatis]] (the "round ligament of the liver").
 |- 
 | intra-hepatic portion of the fetal left umbilical vein (the [[ductus venosus]]) || [[ligamentum venosum]]
 |- 
 | [[distal]] portions of the fetal left and right [[umbilical arteries]] || [[medial umbilical ligaments]]
|}

==Articular ligaments==
[[Image:Gray298.png|thumb|Diagrammatic section of a symphysis.]]
In its most common use, a ''ligament'' is a short band of tough fibrous dense regular [[connective tissue]] composed mainly of long, stringy [[collagen]] fibres. Ligaments connect bones to other bones to form a [[joint]]. (They do ''not'' connect [[muscle]]s to bones; that is the function of [[tendon]]s.)  Some ligaments limit the mobility of articulations, or prevent certain movements altogether.  

Capsular ligaments are part of the articular capsule that surrounds synovial [[joints]]. They act as mechanical reinforcements.  Extra-capsular ligaments join bones together and provide [[joint]] stability.

Ligaments are only slightly elastic; when under tension, they gradually lengthen. (Unlike tendons which are very elastic). This is one reason why dislocated joints must be set as quickly as possible: if the ligaments lengthen too much, then the joint will be weakened, becoming prone to future dislocations. Athletes, gymnasts, dancers, and martial artists perform stretching exercises to lengthen their ligaments, making their joints more supple. The term '''double-jointed''' refers to people who have more elastic ligaments, allowing their joints to stretch and contort further. The medical term for describing such ''double-jointed'' persons is hyperlaxity and double-jointed is a synonym of ''hyperlax''.

The study of ligaments is known as desmology. 

The consequence of a broken ligament can be instability of the joint. Not all broken ligaments need surgery, but if surgery is needed to stabilise the joint, the broken ligament can be joined. Scar tissue may prevent this. If it is not possible to fix the broken ligament, other procedures such as the [[Brunelli Procedure]] can correct the instability. Instability of a joint can over time lead to wear of the cartilage and eventually to [[osteoarthritis]].

===Examples===
====Knee====
* [[Anterior cruciate ligament]] (ACL)
* [[Lateral collateral ligament]] (LCL)
* [[Posterior cruciate ligament]] (PCL)
* [[Medial collateral ligament]] (MCL)
* Cranial cruciate ligament (CrCL) - [[quadruped]] equivalent of ACL
* Caudal cruciate ligament (CaCL) - [[quadruped]] equivalent of PCL

====Head and neck====
*[[Cricothyroid ligament]]
*[[Periodontal ligament]]
*[[Suspensory ligament of the lens]]

====Pelvis====
* [[Anterior sacroiliac ligament]]
* [[Posterior sacroiliac ligament]]
* [[Sacrotuberous ligament]] 
* [[Sacrospinous ligament]]
* [[Inferior pubic ligament]]
* [[Superior pubic ligament]]
* [[Suspensory ligament of the penis]]

====Thorax====
* [[Suspensory ligament of the breast]]

====Wrist====
* See [[Wrist#Ligaments]]

==References==
<references/>

==External links==
{{wiktionarypar|ligament}}
* [http://www.mercksource.com/pp/us/cns/cns_hl_dorlands.jspzQzpgzEzzSzppdocszSzuszSzcommonzSzdorlandszSzdorlandzSzdmd_l_09zPzhtm Exhaustive list of ligaments]
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{{Joints of head and neck}}
{{Joints of upper limbs}}
{{Joints of torso}}
{{Joints of lower limbs}}
{{Peritoneum}}
{{Fetal remnant ligaments}}
[[Category:Skeletal system]]

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