Rhinitis pathophysiology
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Fatimo Biobaku M.B.B.S [2]
Overview
Pathophysiology
Clinically relevant anatomy and physiology of the nose[1][2]
Diagram
The human nose- It is both a respiratory and an olfactory organ. The nose is a highly vascular organ, the nasal blood vessels receive parasympathetic innervation and dense sympathetic innervation. Parasympathetic nerve stimulation promotes secretion from nasal airway glands and nasal congestion while sympathetic nerve stimulation cause a reduction in nasal blood flow, and significant decongestion of the nasal venous erectile tissues. The nasal cavity is divided into right and left halves by the nasal septum. The nasal cavity extends from the vestibule to the nasopharynx, and it is generally divided into three parts namely:
- The vestibule-the area which surrounds the external opening to the nasal cavity.
- The olfactory region-located at the apex of the nasal cavity. It consists of the superior turbinate/concha, and it is lined by olfactory cells.
- The respiratory region-the largest part of the nasal cavity, lined by pseudostratified columnar epithelial cells(about 80% of these cells are ciliated). Interspersed within the epithelium are mucus-secreting goblet cells which are necessary for the maintenance of mucociliary clearance. Factors such as dryness and temperature significantly affect the ciliary function of epithelial cells. Ciliary action stops after 8-10mins at 50% relative humidity of inspired air, and after 3-5mins at 30% relative humidity of inspired air. Ciliary activity ceases at temperatures between 7-12”C. Other factors that significantly impair ciliary function are factors such as environmental exposure to large amounts of wood dust and chromium vapors,tobacco smoke, inhaled gases, locally applied drugs, infection, etc. Ciliary structure changes has been noted in patients with longstanding allergic rhinitis.
The paranasal sinuses- The paranasal sinuses drain into the nasal cavity. The nose and sinuses are contiguous structures, and they share vascular, neuronal and interconnecting anatomic pathways.
Pathophisiology of Allergic Rhinitis
Allergic rhinitis is a multifactorial disease, its development is influenced by an interplay of genetic and environmental factors.[3] Proteins, glycoproteins and rarely, glycans in indoor and outdoor inhalant allergens such as dust mite fecal particles, cockroach residues, animal danders, molds, and pollens commonly cause allergic rhinitis.[3][4]
References
- ↑ Jones N (2001). "The nose and paranasal sinuses physiology and anatomy". Adv Drug Deliv Rev. 51 (1–3): 5–19. PMID 11516776.
- ↑ Watelet JB, Van Cauwenberge P (1999). "Applied anatomy and physiology of the nose and paranasal sinuses". Allergy. 54 Suppl 57: 14–25. PMID 10565476.
- ↑ 3.0 3.1 Bousquet J, Khaltaev N, Cruz AA, Denburg J, Fokkens WJ, Togias A; et al. (2008). "Allergic Rhinitis and its Impact on Asthma (ARIA) 2008 update (in collaboration with the World Health Organization, GA(2)LEN and AllerGen)". Allergy. 63 Suppl 86: 8–160. doi:10.1111/j.1398-9995.2007.01620.x. PMID 18331513 PMID: 18331513 Check
|pmid=value (help). - ↑ Dykewicz MS, Hamilos DL (2010). "Rhinitis and sinusitis". J Allergy Clin Immunol. 125 (2 Suppl 2): S103–15. doi:10.1016/j.jaci.2009.12.989. PMID 20176255.