Lecture for Ch 10.1: Taste and Smell Flashcards
What are taste buds made of?
50-100 specialized epithelial cells with long microvilli that extend out of taste bud pore
Types of papillae on tongue
1) fungiform
2) circumvallate
3) foliate
Fungiform Papillae
on the anterior surface of the tongue, innervated by the facial nerve
Circumvallate Papillae
on the posterior surface of the tongue, innervated by the glossopharyngeal nerve
Foliate Papillae
on the side of the tongue innervated by the glossopharyngeal nerve
Taste Pathways
facial & glossopharyngeal –> medulla oblongata –> thalamus –> primary gustatory cortex of insula/somatosensory lobe/prefrontal cortex
What part of the taste bud comes in contact with chemicals?
microvilli
True/false: each taste buds has sensory cells for each taste category
TRUE
Taste is influenced by the _____ and _____ of the substance
temperature; texture
How does salty reception work?
Na+ received by the hair cell through ion channels, causes depolarization, opens Ca channels to release NT to the synapse for the facial or glossopharyngeal nerve to receive stimulation
How does sour reception work?
H+ received by the hair cell through ion channels, causes depolarization, opens Ca channels to release NT to the synapse for the facial or glossopharyngeal nerve to receive stimulation
How does sweet/umami reception work?
sugar or glutamate binds to receptor, activating g-proteins/2nd messngr to release Ca++ and close K+ channels
How does bitter reception work?
Quanine binds, activating G-protein/2nd messngr to release Ca++ from endoplasmic reticulum; VERY sensitive to [LOW] as a protective response
What are g-proteins called in the gustation system?
gustducins
Which 2nd messngr is activated in sugar reception?
adenylate cyclase, producing cAMP
