Anatomy
Summary
The meninges are membranes that surround the brain and spinal cord. There are three of the them: the dura mater, a fibrous layer closest to the skull containing the dural venous sinuses, the arachnoid mater, a web-like tissue layer, and the innermost layer the pia mater, a thin layer adherent to the surface of the brain and spinal cord.
Between the dura mater and the skull is the epidural space, which contains fat and blood vessels. ItÕs a potential space, but fluid can collect here. When that fluid is blood, itÕs called an epidural hematoma. The subarachnoid space, located beneath the arachnoid mater and above the pia mater, is where the cerebrospinal fluid (CSF) circulates, cushioning and removing waste from the central nervous system. The arachnoid mater interacts with the CSF by reabsorbing it at the arachnoid granulations. The pia mater continues at the end of the spinal cord as the filum terminale, tethering it to the coccyx after fusion with the dura mater.
Lesson Outline
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FAQs
The meninges consist of three layers: the dura mater, arachnoid mater, and pia mater. The dura mater is the outermost, durable layer. The arachnoid mater is the middle layer and its subarachnoid space is filled with cerebrospinal fluid. The pia mater is the innermost layer which is in direct contact with the brain and spinal cord.
The epidural space is a potential space between the dura mater and the skull. An epidural hematoma is an accumulation of blood in this space.
The cerebrospinal fluid (CSF) flows in the subarachnoid space, which lies between the arachnoid mater and the pia Mater. The CSF is produced within the brain's ventricles and circulates through the subarachnoid space. Arachnoid granulations in the arachnoid mater reabsorb CSF.
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