synovial joint

anatomy

Also known as: diarthrosis

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Last updated

July 14, 2026

Quick Summary

A synovial joint, also known as a diarthrosis, is a type of joint that contains fluid and is permanent, meaning the bones do not fuse except due to disease or surgery. These joints are characterized by a cavity enclosed by a wall, which is filled with synovial fluid. This fluid is secreted by the synovial membrane and contains hyaluronic acid, serving as a lubricant and nutrient for the joint cartilage.123

Synovial joints allow for movement, with the amount varying depending on the specific joint. There are seven types of synovial joints, classified by the shape of their articulating surfaces: plane, hinge, pivot, sellar, ellipsoid, spheroidal (ball-and-socket), and bicondylar. Inflammation of the synovial membrane is called synovitis, and it can be caused by various infections or diseases.124

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joint
Structure and elements of synovial joints
The synovial bursas are closed, thin-walled sacs, lined with synovial membrane. Bursas are found between structures that glide upon each other, and all motion at diarthroses entails some gliding, the amount varying from one joint to another. The bursal fluid, exuded by the…
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The synovial bursas are closed, thin-walled sacs, lined with synovial membrane. Bursas are found between structures that glide upon each other, and all motion at diarthroses entails some gliding, the amount varying from one joint to another. The bursal fluid, exuded by the…
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ankle
…in humans, hinge-type, freely moving synovial joint between the foot and leg. The ankle contains seven tarsal bones that articulate (connect) with each other, with the metatarsal bones of the foot, and with the bones of the lower leg. The articulation of one of the tarsal bones, the ankle bone…
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…in humans, hinge-type, freely moving synovial joint between the foot and leg. The ankle contains seven tarsal bones that articulate (connect) with each other, with the metatarsal bones of the foot, and with the bones of the lower leg. The articulation of one of the tarsal bones, the ankle bone…
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skeleton
Joints
…into two main categories, the synovial joint and the nonsynovial joint. In the former, known also as diarthrosis, a cleft occurs between the free surfaces of two skeletal parts; during movements these surfaces slide on each other. In the nonsynovial type, known also as synarthrosis, the skeletal parts are connected…
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…into two main categories, the synovial joint and the nonsynovial joint. In the former, known also as diarthrosis, a cleft occurs between the free surfaces of two skeletal parts; during movements these surfaces slide on each other. In the nonsynovial type, known also as synarthrosis, the skeletal parts are connected…
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