Smell and Taste 1 Anatomy of the olfactory

Smell and Taste 1

Anatomy of the olfactory receptors l Olfactory epithelium ¡Olfactory receptors are localized on the roof of the nasal cavity. Covered by mucus. Bipolar neurons with cilia ¡Supporting cells ¡Basal cells – stem cells ¡Olfactory glands l. Responsible for mucus production 2

Anatomy of the olfactory receptors l Olfactory nerves ¡Penetrates the ethmoid bone l Olfactory bulb l Olfactory tracts l Cerebral cortex – uncus l Olfactory adaptation ¡Partial adaptation: 3 -5 seconds ¡Complete adaptation: 1 -5 minutes 3

Olfactory organs 4

Anatomy of Taste Buds 5

Taste receptors – gustatory cells l Clustered in taste buds l Associated with lingual papillae l Types of lingual papillae ¡Filiform- The more numerous one. No taste buds ¡Fungiform – mushroom-like. Contain taste buds ¡Circumvallate- on a V formation on the back of the tongue. Contain taste buds 6

Taste buds l Basal cells ¡ Stem cells l Supporting cells ¡Insulate the gustatory cells l Gustatory hair ¡Seems to be the sensitive portion of the taste cells ¡They are microvilli l Taste pores ¡Opening for the gustatory hair 7

Gustatory reception 8

Gustatory pathways l Taste buds are monitored by cranial nerves ¡Facial – anterior 2/3 of the tongue ¡Glossopharyngeal- posterior 1/3 of the tongue ¡Vagus –taste buds on the pharynx ¡Synapse within the solitary nucleus of the medulla oblongata ¡Thalamus l Trigeminal – will carry all the other information such as texture, and temperature 9

Taste buds distribution l Sweet receptors ¡Sugar and some aminoacids l Salt ¡Metallic ions l Sour ¡Acid solutions l Bitter ¡alkaloids l Umami ¡Cheese, meat taste 10

Gustatory discrimination l Combine effects of smell, texture and temperature on taste 11