from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The olfactory region of the brain, located in the cerebrum.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The part of the brain involved with olfaction.
from the GNU version of the Collaborative International Dictionary of English
- n. The division of the brain in front of the prosencephalon, consisting of the two olfactory lobes from which the olfactory nerves arise.
from The Century Dictionary and Cyclopedia
- n. The olfactory lobe of the brain; the foremost one of the several morphological segments of the encephalon, preceding the prosencephalon. In the lower vertebrates the rhinencephalon is relatively large, and evidently a distinct part of the brain. In the higher it gradually diminishes in size, becoming relatively very small, and apparently a mere outgrowth of the cerebrum. Thus, in man the rhinencephalon is reduced to the so-called pair of olfactory nerves, from their roots in the cerebrum to the olfactory bulbs whence are given off the numerous filaments, the proper olfactory nerves, which pierce the cribriform plate of the ethmoid, and ramify in the nose. The rhinencephalon, like other encephalic segments, is paired or double—that is, consists of right and left halves. It is primitively hollow or has its proper ventricle, which, however, is entirely obliterated in the adults of the higher vertebrates. This hollow is a prolongation of the system of cavities common to the other encephalic segments, and known as the rhinocœle. Also rhinencephal. See cuts under Petromyzontidæ, Rana, brain (cut 2), and encephalon.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a center in the cerebral hemispheres that governs the sense of smell in lower animals; in humans it seems to mediate complex emotional behavior
Sorry, no etymologies found.