The main function of fibrous joint

The main functions of  fibrous joints is to serves as a  connective tissue or a suture (to bind or sew) which strongly unites the adjacent skull bones and thus helps to protect the brain and form the face. In adults, the skull bones are closely opposed and fibrous connective tissue fills the narrow gap between the bones

Explanation:

and the example of fibrous joints are

yes we can.   a lady urinates from her urethra.