What are the specializations of the arachnoid mater?
There are two subdivisions of arachnoid mater surrounding the subarachnoid space, the dorsal layer and the ventral layer. The dorsal layer covers internal cerebral veins and fixes them to the surrounding tela choroidea.
What is the arachnoid mater composed of?
The arachnoid is composed of collagen and elastic fibers. It has a variable thickness, in places being formed by several cell layers. Its outer (dural) aspect is smoother than the inner (pial) aspect from which trabeculae emerge to bridge the subarachnoid space (Nicholas and Weller, 1988).
What is under the arachnoid mater?
The space under the arachnoid, the subarachnoid space, is filled with cerebrospinal fluid and contains blood vessels. The pia mater is the innermost layer of meninges. This thin, delicate membrane is tightly bound to the surface of the brain and spinal cord and cannot be dissected away without damaging the surface.
What type of connective tissue is arachnoid mater?
elastic connective tissue
The arachnoid mater is the middle layer. It is a thin, web-like membrane that covers the entire brain. The name comes from the spider-web like trabeculae between it and the pia mater. It is made of elastic connective tissue.
How does the dura mater protect the brain?
The dura provides the brain and spinal cord with an extra protective layer, helps to keep the CNS from being jostled around by fastening it to the skull or vertebral column, and supplies a complex system of veinous drainage through which blood can leave the brain.
What are the 3 coverings of the brain?
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.
What happens if pia mater is damaged?
The pia mater allows blood vessels to pass through and nourish the brain. The perivascular space between blood vessels and pia mater is proposed to be part of a pseudolymphatic system for the brain (glymphatic system). When the pia mater becomes irritated and inflamed the result is meningitis.
Which is part of the brain covers the arachnoid mater?
The arachnoid mater covering the brain is referred to as the “arachnoidea encephali,” and the portion covering the spinal cord as the “arachnoidea spinalis.” The arachnoid and pia mater are sometimes considered as a single structure, the leptomeninx, or the plural version, leptomeninges. (“Lepto”- from the Greek root meaning “thin”).
Is the pia mater the same as the arachnoid?
The arachnoid and pia mater are sometimes considered as a single structure, the leptomeninx, or the plural version, leptomeninges. (“Lepto”- from the Greek root meaning “thin”).
Is the arachnoid layer attached to the dura?
The delicate arachnoid layer is not attached to the inside of the dura but against it and surrounds the brain and spinal cord. It does not line the brain down into its sulci (folds), as does the pia mater, with the exception of the longitudinal fissure, which divides the left and right cerebral hemispheres.
Is the arachnoid part of the neural crest?
The arachnoid mater is a derivative of the neural crest mesectoderm in the embryo. It is interposed between the two other meninges, the more superficial and much thicker dura mater and the deeper pia mater, from which it is separated by the subarachnoid space.
