title: The Pathway for Oxygen: Structure and Function in the Mammalian Respiratory System
author: Ewald R. Weibel M.D.
description: This is clearly one of the most outstanding books in physiology/functional anatomy ever to be written.<b><i></i></b><b>C. R. Taylor, Alexander Agassiz Professor of Zoology, Harvard University</b>
zlib_text: RESPONSE TO ODORS
  Richard A. Duffee
  Martha O’Brien
  Odor Science & Engineering Inc.
  Bloomfield , Connecticut
  21.1
  THE NOSE AND HOW IT SERVES US
  The nose is the first internal surface to encounter the ambient air. It is a critical component
  of the body’s defense mechanisms. It begins to warm and moisten the air on its way to our
  lungs. Fine hairs and nasal structure remove some of the particles, including pollens, bac-
  teria, fungi, and dust. The epithelium transitions from skin to squamous epithelium to cili-
  ated secretory lining. The specialized features of the nasal epithelium function by
  presenting a protective barrier. Inhaled noxious materials can be absorbed in the fluid layer
  along with particles and conveyed by cilia transport and swallowed or otherwise removed
  (e.g., by sneezing).
  The nose serves other important functions as well. Through connections to the inner ear,
  we maintain air pressure balance. The act of yawning can move small volumes of air
  through the eustachian tube