Synovial joint 557619 225152002 2008-07-12T04:15:01Z SieBot 4005189 robot Adding: [[he:מפרק סינוביאלי]] '''Synovial joints''' (or '''diarthroses''', or '''diarthroidal joints''') are the most common and most moveable type of [[joint]]s in the human body. As with most other joints, synovial joints achieve movement at the point of contact of the articulating [[bone]]s. Structural and functional differences distinguish synovial joints from cartilagenous joints ([[synchondroses]] and [[symphyses]]) and fibrous joints ([[sutures]], [[gomphoses]], and [[syndesmoses]]). The main structural differences between synovial and fibrous joints is the existence of a capsule surrounding the articulating surfaces of a synovial joint and the presence of lubricating synovial fluid within that capsule. == Types == There are six types of synovial joints. Some are relatively immobile, but are more stable. Others have multiple degrees of freedom, but at the expense of greater risk of injury. In ascending order of mobility, they are:<ref>[http://anatomy.med.umich.edu/modules/joints_module/joints_14.html Module - Introduction to Joints<!-- Bot generated title -->]</ref> {| class="wikitable" | '''Name''' || '''Example''' || '''Description''' |- | ''[[Gliding joint]]s'' (or ''planar joints'') || the [[carpal]]s of the [[wrist]] || These joints allow a wide variety of movement, but not much distance. |- | ''[[Hinge joint]]s'' || the [[Elbow-joint|elbow]] (between the [[humerus]] and the [[ulna]]) || These joints act like a [[door]] [[hinge]], allowing flexion and extension in just one plane. |- | ''[[Pivot joint]]s'' || the elbow (between the [[radius (bone)|radius]] and the [[ulna]]) || This is where one bone rotates about another. |- | ''[[Condyloid joint]]s'' (or ''ellipsoidal joints'') || the [[wrist]]|| A condyloid joint is where two bones fit together with an odd shape (e.g. an [[ellipse]]), and one bone is concave, the other convex. Some classifications make a distinction between condyloid and ellipsoid joints. |- | ''[[Saddle joint]]s'' || the [[thumb]] (between the [[metacarpal]] and [[carpal]]) || Saddle joints, which resemble a [[horse tack|saddle]], permit the same movements as the condyloid joints. |- | ''[[Ball and socket joint]]s'' || the [[shoulder]] and [[hip]] joints || These allow a wide range of movement. |} == References == {{Reflist}} {{musculoskeletal-stub}} [[he:מפרק סינוביאלי]] [[zh:滑液關節]]