Choroid plexus

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A choroid plexus , also written plexus chorioideus or plexus chorioides (in the plural: the plexūs chor [i] oidei / chorioides ), is a tree-like branched plexus of veins in one of the ventricles of the cavity system of the brain emerging from the neural tube lumen . Each of the four ventricles has such a plexus of veins, also known as villi bulges. The choroid plexus form the brain and spinal fluid ( CSF ) new and transfer it into the ventricular system as internal CSF space .

Posterior view of the opened ventricular system of a brain specimen .
In the center of the picture the choroid plexus of the two lateral ventricles and the III. Ventricle -
after the removal of significant parts of the cerebral hemispheres through transversal and frontal incisions as well as separation of the cerebellum including the choroid plexus of the fourth ventricle -
as well as the floor of the diamond pit , partly formed by the pons' bridge, exposed underneath .

The choroid plexus of both lateral ventricles and that of the III. Ventricles communicate and are suspended from taenien.

In the lateral ventricle, these include:

  • Fimbria hippocampi (also called Fimbria fornicis)
  • Taeniae fornicis
  • Taenia choroidea (lying on the back of the thalamus)

as well as in the 3rd ventricle:

  • Taenia thalami (located on the upper, medial edge of the thalamus, running along the stria medullaris thalami)

They are therefore located on the thalamus , the fornix and the hippocampus.

The choroid plexus of the fourth ventricle starts from its roof, caudal to the inferior medullary sail. The part that protrudes from the lateral openings (Aperturae laterales ventriculi quarti or Foramina Luschkae ) into the subarachnoid space is clinically called Bochdalek's flower basket .

The CSF is essentially formed by ultrafiltration of the blood . In addition, active release ( secretion ) increases the concentration of sodium and magnesium compared to the blood . The amount of CSF formed is around 0.3-0.4 ml / min, i.e. around 500 ml per day. The volume of approx. 150 ml contained in the liquor spaces is thus renewed and the ventricular system thus flows through from the sites of formation in the side ventricles in the direction of the openings in the fourth ventricle into the subarachnoid space as the outer liquor space.

histology

Choroid plexus histology .
Hematoxylin-eosin stained section. Original magnification 1: 100

A choroid plexus consists of an invagination of the soft meninges ( pia mater ) and its epithelial coating of cells of the neuroglia , specialized ependymal cells , of the neuroepithelium that emerged from the wall of the embryonic neural tube . This single-layer, cubic epithelium of the ependyma shows, as the lamina choroidea, not only cinema cilia but also numerous microvilli on the surface. Underneath is the vascular layer of connective tissue , the Tela chorioidea , of mesenchymal origin , which comes from the pia mater . The venous plexuses are supplied with blood via side branches of the internal carotid artery and the posterior cerebral artery (caudalis).

Diseases

A plexus cyst is a harmless cystic structure in the brain of unborn children. A benign tumor of the choroid plexus is called a plexus papilloma , a malignant plexus carcinoma . About 70% of the plexus papillomas are diagnosed in children under 2 years of age, but can occur and become symptomatic in all age groups.

literature

  1. ^ W. His: The anatomical nomenclature. Nomina Anatomica. The anatomical society on its IX. At the meeting in Basel . Veit & Comp publishing house, Leipzig 1895.
  2. ^ S. Suzuki, T. Katsumata, R. Ura, T. Fujita, M. Niizima, H. Suzuki: About the Nomina Anatomica Nova. In: Folia Anatomica Japonica. 14, 1936, pp. 507-536.
  3. ↑ Sobotta, Johannes 1869-1945, Waschke, Jens 1974-, Paulsen, Friedrich 1965-: Sobotta, Atlas of Anatomy - Head, Head, Neck and Neuroanatomy . 24th edition. Munich, ISBN 978-3-437-44023-6 .
  4. ↑ Sobotta, Johannes 1869-1945, Waschke, Jens 1974-, Paulsen, Friedrich 1965-: Sobotta, Atlas of Anatomy - Head, Head, Neck and Neuroanatomy . 24th edition. Munich, ISBN 978-3-437-44023-6 .
  5. ↑ Sobotta, Johannes 1869-1945, Waschke, Jens 1974-, Paulsen, Friedrich 1965-: Sobotta, Atlas of Anatomy - Head, Head, Neck and Neuroanatomy . 24th edition. Munich, ISBN 978-3-437-44023-6 .
  6. ↑ Sobotta, Johannes 1869-1945, Waschke, Jens 1974-, Paulsen, Friedrich 1965-: Sobotta, Atlas of Anatomy - Head, Head, Neck and Neuroanatomy . 24th edition. Munich, ISBN 978-3-437-44023-6 .
  7. ↑ Plexus papilloma. Retrieved May 23, 2020 .

Web links

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