Meninges

The meninges (singular meninx) are the system of membranes that contain the central nervous system. It consists of three layers, the dura mater, the arachnoid mater, and the pia mater.

Related Topics:
Membrane - Central nervous system - Dura mater - Arachnoid mater - Pia mater

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• The pia or pia mater is a very delicate membrane. It is closest to the brain or the spinal cord. As such it follows all the minor contours of the brain (gyri and sulci).
• The middle element of the meninges is the arachnoid mater, so named because of its spider web-like appearance.
• The dura mater is a thick, durable membrane, closest to the skull.

The arachnoid and pia mater are sometimes together called the leptomeninges.

Related Topics:
Arachnoid - Pia mater

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The subarachnoid space is the space that normally exists between the arachnoid and the pia.

Related Topics:
Subarachnoid space - Arachnoid - Pia

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Normally, the dura mater is attached to the skull in the head, or to the bones of the vertebral canal in the spinal cord. The arachnoid is attached to the dura mater, and the pia mater is attached to the central nervous system tissue. When the dura mater and the arachnoid separate through injury or illness, the space between them is the subdural space.

Related Topics:
Dura mater - Skull - Spinal cord - Arachnoid - Pia mater

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A subdural hematoma is, therefore, a separation of the arachnoid from the dura mater. The small veins that connect the dura mater and the arachnoid are torn, and blood can leak into this area. Other medical conditions that affect the meninges include meningitis, a viral or bacterial infection.

Related Topics:
Subdural hematoma - Arachnoid - Dura mater - Meningitis - Viral - Bacterial

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