What part of the brain is referred to as a blanket?

The meninges are referred to as a blanket because they are protective coverings that envelop the brain and spinal cord. Comprising three layers – the dura mater, arachnoid mater, and pia mater – these membranes serve as a protective barrier, cushioning the central nervous system from injury and infection. The term "blanket" metaphorically describes their function of encasing and safeguarding the delicate structures of the brain much like a blanket provides warmth and security.