Translations:Benutzer:Arian/Klett-Mini-Test/377/en

The encasing of the head consists predominantly of the hard, heavily mineralised cranial bones. These enclose the cranial cavity, which is filled by the cerebrospinal fluid — a water-clear, cell-free and protein-free liquid — and, floating within it, by the brain itself. Beyond this, the sense organs serving waking consciousness are concentrated in the head. In them, as in the head as a whole, life recedes far behind the prevailing rule of the physical. This is shown impressively in the anatomical structure of the eye — with, among other things, the light-refracting lens — or of the ear, with its tympanic membrane, the chain of ossicles, and the bony labyrinth. The head pole stands closer to what is purely physical, to death, than to life. Morphologically, the head is an image of congealed life processes. Even the brain, in its physiological activity as the organ that produces consciousness, is quietly traversed by processes of dying. Nerve and brain are, after injury, no longer capable of regeneration after a short time. The process that governs them is of a breakdown nature. Of this speaks the high respiratory activity of the brain and the necessity of intensive oxygen supply through the blood. The