COM Nasal Breathing & Airway Function 1 — Questions and Answers
Question 1: What is the primary advantage of nasal breathing over mouth breathing for inspired air?
- It filters, warms, and humidifies air before it reaches the lungs (Correct answer)
- It increases the total volume of air intake per breath
- It reduces the work of the diaphragm during inhalation
- It speeds up gas exchange in the alveoli
Correct answer: It filters, warms, and humidifies air before it reaches the lungs
Nasal breathing conditions incoming air by filtering particulates, warming it to body temperature, and adding humidity, protecting the lower airways.
Question 2: Which nasal structures are primarily responsible for warming and humidifying inspired air?
- Nasal septum
- Cribriform plate
- Turbinates (conchae) (Correct answer)
- Eustachian tubes
Correct answer: Turbinates (conchae)
The turbinates (conchae) create turbulent airflow and have a rich blood supply and mucosa that warm and humidify air as it passes through.
Question 3: Nitric oxide (NO) produced in the nasal sinuses during nasal breathing primarily functions to:
- Increase mucus viscosity for better filtration
- Reduce the pH of inspired air
- Act as a vasodilator and bronchodilator, improving oxygen uptake (Correct answer)
- Stimulate the olfactory nerve for scent detection
Correct answer: Act as a vasodilator and bronchodilator, improving oxygen uptake
Nasally produced nitric oxide is inhaled into the lungs where it acts as a potent vasodilator and bronchodilator, enhancing oxygen absorption.
Question 4: In clinical orofacial myofunctional practice, the 'nasal cycle' refers to:
- The rhythm of nasal breathing during non-REM sleep stages
- Seasonal variations in nasal allergy presentations
- The production cycle of nasal mucus every 24 hours
- The alternating congestion and decongestion between the two nasal passages (Correct answer)
Correct answer: The alternating congestion and decongestion between the two nasal passages
The nasal cycle is a normal physiological process in which the nasal turbinates alternately swell and shrink every 2–7 hours, shifting dominant airflow between nostrils.
Question 5: The nasal mucociliary clearance system protects the airway by:
- Controlling the pH of nasal secretions
- Detecting and neutralizing airborne allergens chemically
- Trapping pathogens and particles and moving them toward the pharynx for elimination (Correct answer)
- Regulating humidity within the nasal cavity only
Correct answer: Trapping pathogens and particles and moving them toward the pharynx for elimination
Cilia on the nasal mucosa beat in coordinated waves to transport mucus containing trapped particles and pathogens toward the pharynx, where they are swallowed or expelled.
Question 6: Compared to mouth breathing, nasal breathing during rest is associated with:
- Higher levels of sympathetic nervous system activation
- Greater activation of the parasympathetic nervous system and calming effects (Correct answer)
- Increased carbon dioxide retention in the blood
- Reduced diaphragmatic excursion
Correct answer: Greater activation of the parasympathetic nervous system and calming effects
Nasal breathing tends to activate the parasympathetic nervous system, promoting relaxation and efficient gas exchange, unlike mouth breathing which can trigger a stress response.
Question 7: In orofacial myology, proper nasal breathing at rest is most closely associated with which tongue position?
- Tongue tip resting behind lower incisors
- Tongue pressed against the buccal mucosa
- Tongue resting on the floor of the mouth
- Tongue body resting against the palate with tip at the incisive papilla (Correct answer)
Correct answer: Tongue body resting against the palate with tip at the incisive papilla
Correct tongue rest posture (tongue body against the palate, tip at the spot/incisive papilla) naturally closes the oral airway and directs breathing through the nose.
COM Nasal Breathing & Airway Function 1
What is the primary advantage of nasal breathing over mouth breathing for inspired air?