Taste and Smell

• Olfactory receptors adapt fairly rapidly
• Taste


  Sense organs for taste are the taste buds in the tongue papillae containing the gustatory receptors
• There is a close relationship between smell and sexual function in many species of animals


  Sense of smell is more acute in females than in males and it is more acute during ovulation
• Four basic tastes


  • Sour – taste buds at the edges of the tongue
  • Sweet – tip of the tongue
  • Bitter – back of the tongue
  • Salty – anterior dorsum of the tongue
• Taste and smell


  • Generally classified as visceral senses because of their close association with gastrointestinal function
  • Flavor of food is a combination of its taste and smell
  • Taste and smell receptors are chemo receptors stimulated by molecules in solution in the fluids of the nose and mouth
• Taste is subserved by


  The facial and glossopharyngeal nerves
• Taste


  Center is at the postcentral gyrus
• Naked nerve endings of the trigeminal nerve at the olfactory mucous membrane can be stimulated by irritating substances


  Produces sneezing, lacrimation, and respiratory inhibition
• Smell receptors


  • They are telereceptors or distant receptors located in the specialized portion of the nasal mucosa
  • Well-developed in dogs and other animals
  • Humans can distinguish between 2,000 – 4,000 different odors but the physiologic basis of this olfactory discrimination is not known
• Smell receptors


  Subserved by the olfactory nerve and the center is at the olfactory cortex
• Sniffing


  Semireflex response that usually occurs when a new odor attracts attention