REACTIONS OF THE NASAL CAVITY AND POSTNASAL SPACE TO CHILLING OF THE BODY SURFACE : I. VASOMOTOR REACTIONS

Area of Science:

• Physiology
• Nasal Physiology
• Thermoregulation

Background:

• The nasal cavity and postnasal space are critical for respiratory health.
• Local temperature variations in the nasal mucosa can indicate physiological responses.
• Understanding these responses is key to managing respiratory conditions.

Purpose of the Study:

• To investigate the effects of body surface chilling on nasal and nasopharyngeal mucosal temperatures.
• To measure local temperature variations using thermopile devices.
• To understand the underlying mechanisms of these temperature changes, specifically reflex vasoconstriction.

Main Methods:

• Utilized specialized thermopile devices to measure temperature at the nasal cavity and postnasal space.
• Applied body surface chilling to subjects and monitored mucosal temperature responses.
• Observed changes in blood supply and mucous membrane condition post-chilling and rewarming.

Main Results:

• Body surface chilling consistently reduced nasal mucosal temperature by up to 6°C and nasopharyngeal temperature by 1-2°C.
• These temperature drops were attributed to reflex vasoconstriction and reduced blood supply (ischemia).
• Rewarming led to prompt but often incomplete recovery of blood supply to the nasal mucosa.

Conclusions:

• Cold exposure triggers significant vasoconstriction in the nasal and nasopharyngeal mucosa.
• The recovery of blood flow is often incomplete, potentially impacting nasal health.
• Reflex vasoconstrictor thresholds vary across different mucosal surfaces and skin, with nasal and pharyngeal areas being more sensitive to cold than forehead skin.