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Clinical Effects of Pollution
Published in William J. Rea, Kalpana D. Patel, Reversibility of Chronic Disease and Hypersensitivity, Volume 5, 2017
William J. Rea, Kalpana D. Patel
The olfactory nerve fibers leading backward from the bulb are called cranial nerve I, or the olfactory tract. However, in reality, both the tract and the bulb are an anterior outgrowth of brain tissue from the base of the brain; the bulbous enlargement at its end, the olfactory bulb, lies over the cribriform plate, separating the brain cavity from the upper reaches of the nasal cavity. The cribriform plate has multiple small perforations through which an equal number of small nerves pass upward from the olfactory membrane in the nasal cavity to enter the olfactory bulb in the cranial cavity. Figures 2.1 through 2.3 demonstrate the close relation between the olfactory cells in the olfactory membrane and the olfactory bulb, showing short axons from the olfactory cells terminating in multiple globular structures within the olfactory bulb called glomeruli. Each bulb has several thousands of such glomeruli, each of which is the terminus for about 25,000 axons from olfactory cells. Each glomerulus also is the terminus for dendrites from about 25 large mitral cells and about 60 smaller tufted cells, the cell bodies of which lie in the olfactory bulb superior to the glomeruli. These dendrites receive synapses from the olfactory cell neurons, and the mitral and tufted cells send axons through the olfactory tract to transmit olfactory signals to higher levels in the CNS. The physiology of this process is accentuated in the chemically sensitive (Figure 2.5).
Effect of head impacts and chemical irritation on elite athletes’ olfaction
Published in European Journal of Sport Science, 2023
Iida-Kaisa Manninen, Laura K. Mäkinen, Pippa Laukka, Tuomas Klockars, Karin Blomgren
For odour sensation, the odorant needs to reach the olfactory epithelium at the top of the nasal cavity. At the epithelium, the odour molecules bind to a receptor, causing the activation of a single nerve cell that runs through the cribriform plate to the olfactory bulb at the base of the brain. At the olfactory bulb, the nerve cell synapses with other neurons (Leopold & Holbrook, 2010).