Objawy okulistyczne w zaburzeniach naczyniowych mózgu.
Część I. Anatomiczne podstawy unaczynienia ośrodkowego układu nerwowego
Ocular Manifestation of the Vascular Brain Disorders.
Part I. Anatomical Basis of the Vascular Supply
Iwona Obuchowska, Zofia Mariak
Klinika Okulistyki Uniwersytetu Medycznego w Białymstoku
Kierownik: prof. dr hab. n. med. Zofia Mariak
Summary: The meninges are the system of membranes from connective tissue, which envelops the central nervous system. They consist of three layers: the dura mater, the arachnoid mater and the pia mater. The space, which normally exists between the arachnoid and the pia mater, and which is filled with cerebrospinal fluid (CSF) is called the subarachnoid space. CSF is produced in the choroid plexus of lateral ventricles, from where it circulates through the interventricular foramina into the third ventricle, and then through the cerebral aqueduct into the fourth ventricle, where it exits through two lateral apertures and one median aperture. It then flows round the spinal cord and the cerebral hemispheres. CSF returns to the vascular system by entering the dural venous sinuses via the arachnoid villi. The primary function of the meninges and CSF is to protect the central nervous system. When CSF pressure is elevated, papilloedema may develop.
Vascular supply of the central nervous system comes from two sources: internal carotid artery and basilar artery. These arteries and their branches form unique circle of arteries called the circle of Willis. Endothelial cells of brain vessels are important structural elements of the blood-brain barrier (BBB), which protect the neural tissue from toxins, buffers variations in blood composition and maintains the brain extracellular environment. An intact BBB and normal production, circulation, and absorption of CSF are critical for normal brain function.
Słowa kluczowe: opony mózgu, przestrzeń podpajęczynówkowa, tarcza zastoinowa, koło tętnicze Willisa, bariera krew–mózg.
Keywords: meninges, subarachnoid space, papilloedema, circulus arteriosus Willis, blood–brain barrier.