Certified Electronic Health Records Specialist (CEHRS) Practice Exam

Which type of joint is described as having a range of motion (ROM)?

1. Synarthroses

2. Amphiarthroses

3. Diarthroses

4. Fibrous joints

The correct answer is: Diarthroses

The type of joint described as having a range of motion is diarthroses. Diarthroses are also known as synovial joints, which are characterized by their ability to allow free movement in various directions. These joints have a synovial cavity filled with fluid, which not only facilitates smooth movements between the articulating bones but also serves to nourish the cartilage covering the ends of those bones. The structure of diarthroses includes important components such as articular cartilage, a joint capsule, and ligaments, all of which contribute to their functional abilities. The range of motion in diarthroses can include actions like flexion, extension, rotation, and gliding, depending on the specific type of synovial joint, such as hinge joints or ball-and-socket joints. In contrast to diarthroses, synarthroses are immovable joints, amphiarthroses allow for limited movement, and fibrous joints are typically fixed or only allow for very slight movement. Understanding these distinctions helps clarify why diarthroses are the type of joint specifically noted for their range of motion.