Final answer:
A syndesmosis is structurally a fibrous joint and functionally an amphiarthrosis, allowing limited movement and providing stability.
Step-by-step explanation:
The answer to the question Structurally, a syndesmosis is a _________ joint; functionally, it is a _________ is: b. fibrous; amphiarthrosis. A syndesmosis is a type of fibrous joint found between parallel bones, where the bones are joined by fibrous connective tissue. Functionally, a syndesmosis is classified as an amphiarthrosis, which allows for limited movement between the bones it connects. This type of joint provides a balance between mobility and stability, thus serving functions like providing protection to internal organs or strength and weight-bearing stability to body regions.