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Physiology of the Nose and Paranasal Sinuses
Published in R James A England, Eamon Shamil, Rajeev Mathew, Manohar Bance, Pavol Surda, Jemy Jose, Omar Hilmi, Adam J Donne, Scott-Brown's Essential Otorhinolaryngology, 2022
The nasal cycle is a physiological process during which each side of the nose alternates between congestion and decongestion. Changes are cyclical, occurring every 4–12 hours and are present in 80% of adults, although difficult to demonstrate in children. Nasal cycle is operated by the autonomic nervous system, which regulates constriction of the arterioles, precapillary sphincters and venous sinusoids within the erectile mucosa. Amplitude of nasal cycle may be influenced by exercise, pregnancy, hormones, congestion, allergy, fear, emotions and sexual activity.
Rhinitis
Published in Pudupakkam K Vedanthan, Harold S Nelson, Shripad N Agashe, PA Mahesh, Rohit Katial, Textbook of Allergy for the Clinician, 2021
Vinay Mehta, Srinivasan Ramanuja, Pramod S Kelkar
The trigeminal nerve provides sensory fibers to the nasal mucous membrane; when these fibers are activated, it produces sensations of irritation or pain, which can result in sneezing. Sympathetic fibers, which follow the blood vessels release noradrenaline and neuropeptide Y, causing vasoconstriction. The nasal cycle involves increasing patency in alternate nostrils (every 2–4 hours), reflecting fluctuations in a sympathetic tone throughout the day.
Aesthetic
Published in Tor Wo Chiu, Stone’s Plastic Surgery Facts, 2018
Nasal cycle – the IT undergoes a 3- to 4-hourly cycle of congestion and decongestion in 80% of the population. This is a normal phenomenon; persistent congestion due to turbinate hypertrophy may warrant turbinectomy.
Effects of unilateral sinonasal surgery on sleep-disordered breathing
Published in Acta Oto-Laryngologica, 2019
Kojiro Ishioka, Hitoshi Okumura, Takanobu Sasaki, Masanao Ikeda, Nao Takahashi, Hironori Baba, Naotaka Aizawa, Arata Horii
In normal subjects, bilateral nasal resistance is usually consistent without changes by time due to the nasal cycle whenever it is measured. In the crest cycle of the healthy side, the disease side must be in the trough cycle. In the crest cycle of the healthy side (= trough cycle of the disease side) in unilateral patients, if the lesion is mild, the air space of the disease side may be wide enough that does not affect the bilateral nasal resistance. Therefore, the present findings that unilateral surgery decreased the bilateral resistance is somewhat surprising. Even in patients with unilateral disease, pre-operative bilateral nasal resistance (0.30 ± 0.25 Pa/cm3/s) was higher than normal range (<0.25) [16], indicating that unilateral nasal lesion can cause bilateral nasal obstruction. Nasal resistance is usually quantified bilaterally [17], because unilateral nasal resistance could be affected by the differences in phase (right or left) of nasal cycle. However, the above results suggest that bilateral nasal resistance may be sufficiently high due to the nasal lesions in the affected side, which could diminish the effects of nasal cycle of the healthy side. Nasal resistance of the surgical side significantly decreased from 0.96 ± 0.86 to 0.30 ± 0.13 Pa/cm3/s after surgery (Figure 1(b)). Moreover, not only nasal resistance of the surgical side but also bilateral nasal resistance was improved after surgery (Figure 1(a)). Since nasal resistance of non-surgical side was not changed by surgery (Figure 1(c)), it is indicated for the first time that even unilateral surgery could affect the bilateral nasal resistance, which may lead to a decrease in 3%ODI (Figure 2).
Voxel-based modeling of airflow in the human nasal cavity
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2019
Shinya Kimura, Takashi Sakamoto, Toshihiro Sera, Hideo Yokota, Kenji Ono, Denis J. Doorly, Robert C. Schroter, Gaku Tanaka
Figure 5 shows details of the nasal airway. In this model, though the perimeter through each cavity is almost the same, there are significant asymmetric differences in the structure of the right and left cavities, with the left cross-sectional area approximately 1.4 times larger than that in the right. This is an effect of structural differences, the nasal cycle, or reactions to allergens/infections (Eccles 2000). The nasal airways are separated by the septum, which is composed of cartilage tissue. The left and right hydraulic diameters (= 4 × area/perimeter) at the nasal valve in plane 2, where the cross-sectional area often attains a minimum, are 8.2 mm and 8.9 mm. The nasal airway extends vertically at its posterior to the nasal valve. The turbinate region consists of a slit-like common meatus connected to the superior, middle, and inferior meatus between planes 4 and 6. The upper part of the common meatus contains the olfactory epithelium, which contains sensory nerve endings for smell. Both airways join at plane 8 before the nasopharynx at plane 9. The paranasal sinuses surrounding the nasal cavity are connected via small orifices. In this study, the paranasal sinuses were excluded from the computational domain. Thus, this complex anatomy is characteristic of the nasal cavity. To estimate the geometry of the nasal cavity quantitatively, the complexity is defined as: l is the perimeter and A is the cross-sectional area. Figure 4(d) shows the complexity distribution as a function of distance from the nose tip. The cross-section at plane 5 has the highest complexity of 37, which is equivalent to gathering this number of parallel tubes, although the nasal cavity has only two passages.
Computational modelling of nasal respiratory flow
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2020
H. Calmet, K. Inthavong, H. Owen, D. Dosimont, O. Lehmkuhl, G. Houzeaux, M. Vázquez
The flow distribution through a cross-section in the middle of the nasal cavity (defined in Figure 1 located approximately 6 cm away from the nose tip) is shown in Figure 8. The proportion of flow, Q passing through the left and right cavities showed the model had one decongested chamber (right) and the other was congested (left) - characteristic of the nasal cycle phenomenon. Both laminar and LES models provided similar solutions where the difference was 0.3% during the inhalation phase and 2% during the exhalation phase.