Final answer:
The knee and temporomandibular joint (TMJ) are the articulations that may be described as diarthrotic, which denotes they are synovial joints allowing free movement in one or multiple planes.
Step-by-step explanation:
The articulations that may be described as diarthrotic are the joints that allow for free movement and are characterized as synovial joints. Diarthrosis is classified based on the number of axes of motion they provide, which correlates with whether they are uniaxial, biaxial, or multiaxial joints.
- The knee joint is a diarthrotic joint that functions primarily as a pivot, allowing uniaxial movement (flexion and extension).
- Intervertebral joints are not considered diarthrotic; instead, they are plane joints that provide only limited motion.
- The temporomandibular joint (TMJ) is a diarthrotic joint because it allows for a variety of motions including elevation/depression, protraction/retraction, and side-to-side movements of the lower jaw.
Therefore, the joints classified as diarthrotic in the provided options are the knee and temporomandibular joint (TMJ).