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Upper Respiratory Tract

Upper Respiratory Tract

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UPPER RESPIRATORY TRACT
  • Begins at the nose and ends with the pharynx.
Nose:
  • Opens the respiratory system to the external environment via the nostrils (aka, nares).
  • Comprises bone and cartilage.
Nasal cavity:
  • Posterior to the nose
  • Separated from the oral cavity by the hard and soft palates:
    • The hard palate comprises the maxillary and palatine bones.
    • The soft palate comprises soft tissues.
  • Olfactory cells line the superior part of the nasal cavity
  • The nasal septum divides the cavity into right and left sides.
    • It comprises two vertical bony structures: the perpendicular plate of the ethmoid bone superiorly and the vomer, inferiorly.
    • A deviated nasal septum can obstruct airflow and cause sinusitis (sinus infection), epistaxis (nose bleeds), anosmia (inability to smell), and other health problems.
  • 3 nasal conchae: superior, middle, and inferior.
    • Bony projections that arise on the lateral walls of the nasal cavity.
    • The nasal conchae create meatuses (superior, middle, and inferior), which are small tunnels.
    • Movement of air around the conchae and through the meatuses creates turbulence, which helps to warm and humidify the air. Hence, the conchae are sometimes referred to as the "turbinate" bones.
Pharynx:
  • Descends posterior to the nasal cavity, oral cavity, and larynx, and is open to each of these structures.
  • Common passageway foods/liquid and air: it serves both the respiratory and digestive systems.
  • 3 subdivisions:
    • Nasopharynx: posterior to the nasal cavity (and receives air from the nasal cavity);
The choanae are the openings between the nasal cavity and the nasopharynx. Oropharynx: posterior to the oral cavity (and receives foods and liquids from the oral cavity); The fauces is the opening between the oral cavity and the oropharynx.
    • Laryngopharynx: posterior to the larynx (it is the final common passageway for air and food/liquid).
  • The auditory tube (aka, Eustachian or pharyngotympanic tubes) opens into the nasopharynx
    • Connects the ears and throat, which allows infection to pass between them.
    • Auditory tube inflammation occurs in otitis media (aka, ear infection), which is common amongst children.

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