The renal capsule is a tough fibrous layer surrounding the kidney and covered in a thick layer of perinephric adipose tissue. It provides some protection from trauma and damage.The renal capsule relates to the other layers in the following order (moving from innermost to outermost):1  renal medulla.2  renal cortex. 3  renal capsule.t provides some protection from trauma and damage. The renal capsule relates to the other layers in the following order (moving from innermost to outermost): 1  renal medulla. 2  renal cortex. 3  renal capsule.