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Purves D, Augustine GJ, Fitzpatrick D, et al., editors. Neuroscience. 2nd edition. Sunderland (MA): Sinauer Associates; 2001.

  • By agreement with the publisher, this book is accessible by the search feature, but cannot be browsed.
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Neuroscience. 2nd edition.

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The Meninges

The cranial cavity is conventionally divided into three regions called the anterior, middle, and posterior cranial fossae. Surrounding and supporting the brain within this cavity are three protective tissue layers, which also extend down the brainstem and the spinal cord. Together these layers are called the meninges (Figure 1.18). The outermost layer of the meninges is called the dura mater because it is thick and tough. The middle layer is called the arachnoid mater because of spiderlike processes called arachnoid trabiculae that extend from it toward the third layer, the pia mater, a thin, delicate layer of cells that closely invests the surface of the brain. Since the pia closely adheres to the brain as its surface curves and folds, whereas the arachnoid does not, there are places—called cisterns—where the subarachnoid space is especially large. The major arteries supplying the brain course through the subarachnoid space where they give rise to branches that penetrate the substance of the hemispheres. The subarachnoid space is therefore a frequent site of bleeding following trauma. A collection of blood between the meningeal layers is referred to as a subdural or subarachnoid hemorrhage, as distinct from bleeding within the brain itself.

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By agreement with the publisher, this book is accessible by the search feature, but cannot be browsed.

Copyright © 2001, Sinauer Associates, Inc.
Bookshelf ID: NBK10877


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