Final answer:
Joints are true skeletal structures that form connections between bones, facilitating movement and providing stability. Their range of motion varies according to their structure and function, with some joints allowing extensive movement and others offering greater stability.
Step-by-step explanation:
Joints, also known as articulations, are skeletal structures that serve as interfaces or connections between bones. This statement is true. Joints are classified based on their structure and function. Structurally, they can be fibrous, cartilaginous, or synovial, based on the material composing the joint and the presence or absence of a cavity. Functionally, they are classified by their range of motion, from immobile to slightly mobile to freely movable.
The majority of joints allow movement to various degrees, depending on their type and location. For example, synovial joints provide a wide range of motion and include most joints in the appendicular skeleton. Conversely, fibrous joints are quite stable and include most of the joints in the skull. This stability and movement capability are crucial for the joint's specific functional requirements, whether it's to provide protection, like the skull protecting the brain, or to facilitate movement, such as the synovial joints that allow you to kick or dance.
The articulating surfaces of bones in the joints are often covered with a smooth layer of cartilage, reducing friction and wear. Muscles work in conjunction with joints to facilitate movement, acting as levers while joints serve as fulcrums.