Special Senses: Smell & Taste Flashcards
→ Stimulated by chemicals in solution
→ Taste has five types of receptors
→ Smell can differentiate a wider range of chemicals
→ Both senses complement each other and respond to many of the same stimuli
Chemoreceptors
→ Located in the roof of nasal cavity → Comprise approximately 10 million olfactory receptor cells (neurons) with long cilia known as olfactory hairs.
→ These olfactory hairs detect chemicals dissolved in the mucus, which bathes the nasal cavity.
→ Once chemicals stimulate the olfactory hairs, impulses are sent through olfactory filaments to the olfactory nerve (Cranial Nerve I).
Olfactory receptors
The _______ transmits signals to the olfactory cortex in the brain, where smells are interpreted.
olfactory nerve
→ house the receptor organs; are replaced frequently by basal cells
→ Locations of taste buds:
○ Most are on the tongue
○ Soft palate
○ Superior part of the pharynx
○ Cheeks
Taste buds
The tongue is covered with projections called _____ that contain taste buds
Papillae
These epithelial cells are the taste
receptors and possess gustatory hairs (long microvilli).
Gustatory cells
Protrude through taste pores and are
stimulated by chemicals dissolved in saliva.
Gustatory hairs
Served the anterior two-thirds of the
tongue
Facial Nerve (Cranial Nerve VII)
Serves the posterior part of the tongue
Glossopharyngeal Nerve (Cranial Nerve IX)
Serves areas like the throat containing taste buds.
Vagus Nerve (Cranial Nerve X)
Respond to sugars, saccharine, some
amino acids
Sweet receptors
Respond to Hydrogen ions or acids
Sour receptors
Respond to alkaloid
bitter receptor
Respond to metal ions
Salty receptors
Respond to the amino acid glutamate or the beefy taste of meat
Umami receptors
