Distributorless ignition systems (DIS) have been around for almost a decade now, and have eliminated much of the maintenance that used to be associated with the ignition system. No distributor means thereâs no distributor cap or rotor to replace, and no troublesome vacuum or mechanical advance mechanisms to cause timing problems.
Olfactory sensitivity is directly proportional to the area in the nasal cavity near the septum reserved to the olfactory mucous membrane, which is the region where the olfactory receptor cells are located. The extent of this area is a specific between animals species.lfactory sensitivity is directly proportional to the area in the nasal cavity near the septum reserved to the olfactory mucous membrane, which is the region where the olfactory receptor cells are located. The extent of this area is a specific between animals species.
The olfactory mucosa is a very important structure as it not only senses smell, but also the more advanced aspects of taste. It is located in the roof of the nasal cavity and is composed of pseudostratified columnar epithelium which contains a number of cells.1  Basal cells: Form the new stem cells from which the new olfactory cells can develop.2  Sustentacular cells: Tall cells for structural support.t is similar to the optic nerve also in its structure, as it has a meningeal covering unlike CN III to XII. Embryologically it is derived from the otic placode (a thickening of the ectoderm layer), which also give rise to the glial cells which support the nerve. The olfactory nerve is also capable of regeneration.