Why we Sneeze...
Sneezing is a protective mechanism of the body designed to expel irritants, such as dust, allergens, or viruses, from the nasal passages. When something irritates the sensitive lining of your nose, your body triggers a sneeze reflex to forcefully expel the irritant. This reflex involves a series of physiological responses that result in a sudden and powerful expulsion of air through your nose and mouth.
Nasal Irritation Detection
Nasal Irritation Detection: Sneezing is triggered by the detection of irritants in the nasal passages. Specialized nerve endings, known as sensory receptors, sense irritants like dust, pollen, or pathogens. These receptors transmit signals to the brain's medulla oblongata, a key region for reflex control.
Protective Reflex
Protective Reflex: Sneezing is a protective reflex designed to clear the respiratory tract of potential threats. When irritants are detected, the brain initiates a rapid response to expel them.
Medulla Oblongata Activation
Medulla Oblongata Activation: The medulla oblongata, acting as a control center, coordinates the sneeze reflex. Neurons in this region send signals to various muscles involved in sneezing. Primarily, the Medulla is the control centre for respiratory and cardiovascular activities. It is responsible to regulate the blood pressure, heart rate, respiratory rate and other such life-sustaining automatic activities.
Muscle Contraction
Muscle Contraction: Muscles involved in sneezing include the diaphragm, intercostal muscles (between the ribs), and muscles controlling vocal cords. The diaphragm contracts forcefully, leading to a sudden increase in pressure within the chest cavity.
Rapid Inhalation
Rapid Inhalation: The pressure buildup leads to a rapid inhalation of air through the nose. This deep inhalation allows a larger volume of air to be expelled during the sneeze.
Closed Glottis
Closed Glottis: The glottis, a part of the larynx, closes during the inhalation phase of the sneeze. This closure prevents the air from escaping through the mouth and directs it towards the nasal passages.
Forceful Exhalation
Forceful Exhalation: The sudden closure of the glottis, combined with the contraction of chest and intercostal muscles, creates a buildup of pressure. The glottis then opens abruptly, and the built-up air is expelled at high speed through the nose and mouth.
Irritant Removal
Irritant Removal: The forceful exhalation expels the irritants from the nasal passages and the respiratory tract. This helps to prevent irritants from reaching deeper into the lungs, protecting delicate lung tissues.
Aerosol Dispersal
Aerosol Dispersal: Sneezing generates an aerosol, a fine mist of tiny droplets that may carry irritants, pathogens, or allergens. The dispersal of these droplets into the air reduces the concentration of irritants in the immediate environment.
Sensory Receptor Reset
Sensory Receptor Reset: After the sneeze, the sensory receptors in the nasal passages are momentarily reset. This reset allows the body to be sensitive to new irritants that may enter the respiratory system.
Conclusion: In summary, sneezing is a complex reflexive response orchestrated by the brain's medulla oblongata. It involves the activation of various muscles and physiological mechanisms to rapidly expel irritants from the nasal passages and respiratory tract. This reflex plays a vital role in protecting the respiratory system from potential harm caused by foreign particles, allergens, and pathogens.
