The brain and spinal cord are surrounded by three layers of membrane: the meninges; they are the hard mother, the arachnoid and the magpie mother; the last two, piamadre and arachnoidea, form the leptomeninge, while the mother lasts pachymeninge form.
The main function of meninges is to provide a protective layer to the brain, a very vulnerable organ, so it needs special protection that no one else has, at least not in the same way. Therefore, brains are responsible. In addition, these protective layers contribute to the blood brain barrier.
- Meninges develop from a precursor layer known as primitive meninges; is composed of elements derived from the mesenchym and neural crest; in addition.
- It is separated into two distinct layers: internal endomening and external ectomening.
Endomening differs in arachnoids and magpie-mother and is derived from both mesoderm and ectoderm. Ectomening forms the durater and bones of the neuroranial and forms only from mesoderm.
It’s the outerest layer. The hard mother consists of two layers, the first, the outer layer, is the periostio of the skull and contains blood vessels and nerves; adheres to the inner surface of the skull with joints specially adjusted to the sutures and base of the skull. .
The deepest layer of maternal law is known as the meninggeal layer and is responsible for the formation of reflexes that divide the brain into compartments.
Of these compartments, the most important are the brain scythe and the cerebellum tent. Furthermore, there is no distinctive boundary between the hard-headed and intelligent mother and the periosteum; this only occurs when they separate to form the dural venous sinuses. histologically differentiated by the fact that the meningeal layer has fewer fibroblasts and proportionally less collagen (2).
Arachnoids is the middle layer of meninges, containing subarachnoid space which, in turn, stores cerebrospinal fluid (CSF). The depth of subaracnoid space varies depending on the relationship between the arachnoid and magpie-mother layers.
This layer is composed of two different layers of cells, after the edge of the hard mother cells is the cell layer of the arachnoid barrier (3). This layer is full of cells well connected by many demosomas and narrow joints. give the layer a barrier function that prevents the movement of liquid through it.
At the bottom of the arachnoid is the reticular arachnoid layer, the cells in this layer join the subaracnoid space and join the mother magpie, as well as involve the blood vessels that pass through the diaper (1).
The magpie is the innerst layer of meninges; it is a delicate, well-vascularized structure and connective tissue that surrounds and protects the brain and spinal cord.
It forms a continuous layer of well-attached cells on the surface of the brain that sink into cracks and grooves. Cells are connected by interconnecting demosomas and joints, allowing this layer to perform a barrier function.
Virchow-Robin’s spaces are spaces around the vessels (perivasculars) that surround small arteries and arterioles, pierce the surface of the brain, and extend into subaracnoid space (1).
These spaces have been shown to increase in size with age, with no apparent loss associated with cognitive function (4), and dilation of these spaces is associated with pathologies such as hypertension, neuropsychiatric disorders, multiple sclerosis and trauma (5). .
In conclusion, the authors Patel and Kirmi (2009) emphasize the importance of knowing the brain, so it is essential to understand the structure, functions and anatomy: this will allow us to understand the extent and location of pathologies related to meninges. , the most common known pathology in relation to these is meningitis.