EVERYDAY SCIENCE

Detailed explanation-1: -The meninges are three layers of protective tissue called as the dura mater, arachnoid mater and pia mater that surround the neuraxis. The outside layer is called as the dura mater and is the most resilient of the three. The centre layer is the arachnoid membrane and the thin innermost layer is the pia mater.

Detailed explanation-2: -Three layers of membranes known as meninges protect the brain and spinal cord. The delicate inner layer is the pia mater. The middle layer is the arachnoid, a web-like structure filled with fluid that cushions the brain. The tough outer layer is called the dura mater.

Detailed explanation-3: -The arachnoid mater, named for its spiderweb-like appearance, is a thin, transparent membrane surrounding the spinal cord like a loosely fitting sac. Continuous with the cerebral arachnoid above, it passes through the foramen magnum and descends caudally to the S2 vertebral level.

Detailed explanation-4: -Tentorium cerebelli is a crescent-shaped fold of the dura mater and forms a roof over the posterior cranial fossa. It shields the superior surface of the cerebellum and supports the occipital lobes of the cerebral hemispheres.

Detailed explanation-5: -Cranial dura mater has two layers called lamellae, a superficial layer (also called the periosteal layer), which serves as the skull’s inner periosteum, called the endocranium and a deep layer called the meningeal layer. When it covers the spinal cord it is known as the dural sac or thecal sac.