Chapter 8, Problem 1RAC

Which of these joints is not matched with the correct joint type?

1. parietal bone to occipital bone-suture
2. between the hip bones-symphysis
3. humerus and scapula-synovial
4. shafts of the radius and ulna-synchondrosis
5. teeth in alveolar process-gomphosis

Summary Introduction

Introduction:

Joints are the part of the body that helps in movement. They are formed by the articulation of the surfaces of two or more bones. Joints are differentiated based on their movement. Some joints are freely movable such as synovial joint, whereas, others are immovable such as a suture.

Answer to Problem 1RAC

The correct answer is option (d) shaft of the radius and ulna-. synchondrosis.

Explanation of Solution

Explanation/justification for the correct answer:

Option (d) Shaft of the radius and ulna-. Synchondrosis. This option is not matched correctly. The correct answer is proximal radioulnar joint and distal radioulnar joint that show pivot movement and it comes under the synovial joint.

Explanation for incorrect answer:

Option (a) parietal bone to occipital bone- suture. This option is correctly matched. Suture joints are present in the middle of bones of the skull which are completely immovable in adults.

Option (b) between the hip bone- symphysis. This option is correctly matched. This is formed from the attachment of two bones by the layers of fibrocartilage. They are slightly movable due to the flexible nature of fibrocartilage.

Option (c) humerus and scapula - synovial. This option is correctly matched. The synovial fluid is present in the middle of the joint that also helps in preventing the friction between the joint. They are freely movable joints.

Option (e) teeth in alveolar process − gomphoses. It is composed of the peg which fits into the socket and kept in place by small bundles of collagenous connective tissue.