amphiarthrooses

Amphiarthrooses are a type of cartilaginous joint that allows for limited movement. Unlike synarthroses, which are immovable joints, and diarthroses, which are freely movable joints, amphiarthroses provide a balance between stability and flexibility. The articular surfaces of the bones in an amphiarthrosis are covered with hyaline cartilage, and the bones are held together by fibrocartilage. This intervening fibrocartilage acts as a shock absorber and allows for slight compression and rotation.

Examples of amphiarthroses include the joints between the vertebrae of the spine, the pubic symphysis, and the sacroiliac joints. The intervertebral joints, for instance, are connected by intervertebral discs made of fibrocartilage. These discs permit slight bending and twisting of the vertebral column, contributing to its overall flexibility. Similarly, the pubic symphysis, located between the two pubic bones of the pelvis, is a strong joint that provides stability to the pelvis, allowing for minimal movement. The sacroiliac joints, formed by the sacrum and the ilium bones of the pelvis, also exhibit limited mobility, crucial for weight bearing and shock absorption. The degree of movement in an amphiarthrosis is typically not significant enough for complex actions but is vital for overall bodily function and structural integrity.