Final answer:
The zygapophyseal (facet) joints are plane or uniaxial joints of diarthrosis providing limited motion in the back, allowing more movement in the cervical and lumbar regions. Intervertebral discs form a different type of joint called an amphiarthrosis, which is also a symphysis cartilaginous joint playing a key role in weight bearing and shock absorption.
Step-by-step explanation:
The zygapophyseal, or facet joints, found in the back are a type of synovial joints. Specifically, they are classified as plane or uniaxial joints of diarthrosis, which permit limited motion primarily in one plane.
These joints involve the articulation between the superior and inferior articular processes of adjacent vertebrae. The range of motion provided by the facet joints is contingent on their orientation, which differs in various regions of the vertebral column, particularly allowing more motion in the cervical and lumbar areas compared to other regions.
Conversely, the joint between adjacent vertebrae that includes an intervertebral disc is classified as an amphiarthrosis type of joint due to its limited movement capability.
Structurally, because intervertebral discs are composed of fibrocartilage, they are also characterized as a type of cartilaginous joint known as a symphysis, which is vital in weight bearing, shock absorption during activities like walking and running, and in binding vertebrae together.