Meninges
The brain and spinal cord are surrounded by three protective membranes called the meninges. The outermost layer is the thick dura mater. The middle layer, the arachnoid, lies adjacent to the dura mater and extends trabeculae through the subarachnoid space to contact the pia mater. The pia mater is a thin layer located directly on the brain or spinal cord. Spinal cord 10x
Spinal cord
The brain and spinal cord are surrounded by three protective membranes called the meninges. The outermost layer is the thick dura mater. The middle layer, the arachnoid, lies adjacent to the dura mater and extends trabeculae through the subarachnoid space to contact the pia mater. The pia mater is a thin layer located directly on the brain or spinal cord. Spinal cord 10x
Dura mater >
The dura mater, the thick outermost membrane, is formed by dense connective tissue. The dura mater contributes to the periosteum of the skull, but is a separate layer from the periosteum of the vertebrae.
Subdural space >
Under normal conditions, the subdural space is a potential space, since the dura mater and arachnoid membranes normally adhere to each other. After head trauma, however, hemorrhaging blood may separate these two membranes, creating a subdural space. The hemorrhaging blood in this space is called a subdural hemotoma.
Arachnoid membrane >
The arachnoid is a delicate layer lying adjacent to the dura mater. It sends weblike trabeculae through the subarachnoid space to the pia mater. The subarachnoid space is filled with cerebrospinal fluid, providing a cushion for the brain or spinal cord. Cranial and spinal nerve roots and blood vessels travel through this space.
Subarachnoid space
The arachnoid is a delicate layer lying adjacent to the dura mater. It sends weblike trabeculae through the subarachnoid space to the pia mater. The subarachnoid space is filled with cerebrospinal fluid, providing a cushion for the brain or spinal cord. Cranial and spinal nerve roots and blood vessels travel through this space.
Nerve roots
The arachnoid is a delicate layer lying adjacent to the dura mater. It sends weblike trabeculae through the subarachnoid space to the pia mater. The subarachnoid space is filled with cerebrospinal fluid, providing a cushion for the brain or spinal cord. Cranial and spinal nerve roots and blood vessels travel through this space.
Blood vessels
The arachnoid is a delicate layer lying adjacent to the dura mater. It sends weblike trabeculae through the subarachnoid space to the pia mater. The subarachnoid space is filled with cerebrospinal fluid, providing a cushion for the brain or spinal cord. Cranial and spinal nerve roots and blood vessels travel through this space.
Pia mater >
The pia mater, a delicate layer lying directly on the surface of the brain or spinal cord, is continuous with the perivascular connective tissue accompanying blood vessels into the brain.
Area shown in the next image
The brain and spinal cord are surrounded by three protective membranes called the meninges. The outermost layer is the thick dura mater. The middle layer, the arachnoid, lies adjacent to the dura mater and extends trabeculae through the subarachnoid space to contact the pia mater. The pia mater is a thin layer located directly on the brain or spinal cord. Spinal cord 10x
