EVERYDAY SCIENCE

Detailed explanation-1: -Fibrous joints called sutures are joints present in the skull. After birth, these joints slowly begin to fuse and become fixed, making the skull bones immovable and thereby, protecting the brain from any physical stress.

Detailed explanation-2: -Synarthroses are immovable joints. The singular form is synarthrosis. In these joints, the bones come in very close contact and are separated only by a thin layer of fibrous connective tissue. The sutures in the skull are examples of immovable joints.

Detailed explanation-3: -The skull is made up mostly of immovable joints due to which skull bones cannot move except for the lower jaw. The lower jaw is connected to the other bones via movable joints which makes its movement possible.

Detailed explanation-4: -Assertion :Sutures present between the skull bones are immovable joints. Reason: There is no space between the skull bones and bones are attached by fibrocartilage.

Detailed explanation-5: -A joint which permits no kind of movement is called as an immovable joint or fixed joint. In such joints, bones have been fused together in such a way that they are fixed to that part. Such joints are found in the skull, upper jaw, rib cage, backbone, pelvic bone, etc.