SCANNING ELECTRON-MICROSCOPY OF HUMAN CEREBRAL MENINGEAL STOMATA

The human dura mater and pia mater were studied by using a scanning el ectron microscope and a computer image processing system (C. I. P.). T he human cerebral meningeal stomata are located between the mesothelia l cells of the cerebral meninges. They are round or oval in shape with diameters of 0.33-2.98 mu m. The cerebral meningeal stomata are stabl e structures, scattered or clustered together. Their density in the du ra mater is greater than in the pia mater (P < 0.01), and they are reg ularly distributed. The statistical analysis showed that the stomata d iameter and distribution density in the dura mater are 1.34 mu m and 3 81.55/0.1 mm(2); while in the pia mater they are 0.88 mu m and 195.06/ 0.1 mm(2) respectively. The cerebral meningeal stomata are probably pa rt of the cerebral prelymphatic capillary system, which undertakes the cerebral lymph drainage because there are no lymphatic vessels in the brain although yet there is lymph drainage. Thus, we believe that the cerebral meningeal stomata are involved in maintaining the physiologi cal function of the brain as part of the cerebrospinal fluid (CSF) whi ch absorbs the cerebral interstitial fluid.