Henry Gray (1825–1861). Anatomy of the Human Body. 1918.
pages 766
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FIG. 677– Scheme showing the connections of the several parts of the brain. (After Schwalbe.) (See enlarged image) |
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FIG. 678– Schematic representation of the chief ganglionic categories (I to V). (Spitzka.) (See enlarged image) |
| 4. The Brain or Encephalon |
General Considerations and Divisions.—The brain, is contained within the cranium, and constitutes the upper, greatly expanded part of the central nervous system. In its early embryonic condition it consists of three hollow vesicles, termed the hind-brain or rhombencephalon, the mid-brain or mesencephalon, and the fore-brain or prosencephalon; and the parts derived from each of these can be recognized in the adult (Fig. 677). Thus in the process of development the wall of the hind-brain undergoes modification to form the medulla oblongata, the pons, and cerebellum, while its cavity is expanded to form the fourth ventricle. The mid-brain forms only a small part of the adult brain; its cavity becomes the cerebral aqueduct (aqueduct of |