Which classification is described as immovable joints?

• A. Diarthrodial
• B. Amphiarthrodial
• C. Synarthrodial
• D. Cancellous

Answer: (C)

Synarthrodial joints are classified as immovable joints, meaning that they do not permit any degree of movement between the adjacent bones. This classification includes joints found in areas such as the skull, where the bones are tightly interlocked by sutures. These joints primarily serve to protect vital structures, such as the brain, providing a rigid, stable interface that ensures integrity and support to the surrounding areas.

In contrast, diarthrodial joints allow for a wide range of motion, commonly found in areas like the knees and shoulders. Amphiarthrodial joints permit slight movement and are typically found in areas such as the spine. The term "cancellous" refers to a type of bone tissue, not a joint classification, and does not relate to joint mobility. Understanding these classifications helps in distinguishing the structural properties and functional roles of different joints in the human body.