Every time you take a breath, all sorts of particles enter your nose, some of them are nothing to be concerned about and some of them not so good for example dirt, viruses, bacteria and even fungus.  Luckily, your respiratory system (e.g. your nose, mouth and lungs) has several defense systems in place to prevent potentially harmful substances from entering your body that can cause infections like colds and flu. 1,2,3

The nasal mucosa (lining in your nose) serves as an air conditioner, a humidifier, a filter and your 1st line of defense. 1,2,3,4

Temperature and moisture control

  • Microvilli and cilia (tiny hair like structures located on the surface of your nose lining) increases the surface area of the nasal lining, this helps to regulate the temperature and moisture of the air you breathe in before it reaches your lungs. When you breathe through your mouth for a long time your throat starts to feel dry, this is because the air did not get the moisture it would have if you breathed through your nose 2,3,4,5

The nose is an excellent filter

  • The hair in your nose is coated with a thin mucus that makes it sticky, this helps to trap particles like dust and pollen to prevent them from making their way to your lungs. The smaller particles like bacteria that slip and through your nasal hair are trapped in your nasal mucus 2,6

Your 1st line of defense

  • The secretion in your nose contains substances that helps to kill unwanted bacteria and viruses2
  • The continuous movement of cilia helps to clear mucus that contains pathogens, allergens, debris, and toxins to assist in immune defense 3,4,7
  • Cells (goblet cells) located in your mucosal lining produce secretions that form a “mucous blanket”. This blanket serves as a protective barrier that helps to prevent pathogens from adhering to your mucosa 4

Now you know why it is so important to protect and take care of your nasal lining.

DISCLAIMER: This editorial has been commissioned and brought to you by iNova Pharmaceuticals. Content in this editorial is for general information only and is not intended to provide medical or other professional advice. For more information on your medical condition and treatment options, speak to your healthcare professional.

Name and business address of the holder of the certificate of registration: iNova Pharmaceuticals (Pty) Ltd,. Co. Reg. No. 1952/001640/07, 15e Riley Road, Bedfordview. Tel. No. 011 087 0000. www.inovapharma.co.za. For further information, speak to your healthcare professional. Further information is available on request from iNova Pharmaceuticals. IN3000/18


  1. Fokkens WJ and Scheeren RA. Upper airway defense mechanisms. Paediatr Respir Rev 2000;1(4):336-341.
  2. American Rhinologic Society. Nasal Physiology. Alt JA and Cohen N [online] 17 February 2018 [Cited] 26 November 2018. Available from URL: http://care.american-rhinologic.org/nasal_physiology?print
  3. Beule AG. Physiology and pathophysiology of respiratory mucosa of the nose and the paranasal sinuses. Head and Neck Surgery 2010;9:1-24.
  4. Sahin-Yilmaz and Naclerio RM. Anatomy and Physiology of the Upper Airway. Proceedings of the American Thoracic Society 2011;8:31-39.
  5. Cleveland Clinic. 7 Surprising Facts about Your Nose. [online] October 2015. [cited January 2019]; Available from URL: https://health.clevelandclinic.org/7-surprising-facts-nose/
  6. Cleveland Clinic. Nose Hair Safari. [online] 26 August 2016 [Cited] 27 November 2018. Available from URL: https://health.clevelandclinic.org/nose-hair-safari-infographic/
  7. Gudis D, Zhao K and Cohen NA. Acquired cilia dysfunction in chronic rhinosinusitis. Am J Rhinol Allergy 2012;26:1-6.
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