Physiology of Taste and Smell Flashcards
what type of receptors are involved in taste and smell and what are they stimulated by?
chemoreceptors, stimulated by binding to particular chemicals
what other type of receptors influence taste perception?
smell receptors
where are most sensory receptor cells found?
in taste buds
what do taste buds consist of and how are they arranged?
sensory receptor cells and support cells, arranged like slices of oranges
what is the life span of taste receptor cells?
about 10 days
what replaces taste receptor cells?
basal cells within the taste buds
what do taste receptor cells within taste buds synapse with?
afferent nerve fibres
how many types of papillae are there in the tongue?
4
what are the 4 types of papillae in the tongue?
filliform, fungiform, vallate and foliate
what type of papillae do not contain taste buds?
filliform
what does binding of taste provoking chemicals to receptor cells cause?
altered cell ionic channels and produces depolarisation receptor potential
what does receptor potential initiate?
action potentials in afferent nerve fibres which synapse with receptor cells
which areas of the brain are signals from receptor cells conveyed to?
cortical gustory areas
afferent nerve fibres from the anterior 2/3rd of tongue reaches the brainstem via what nerve?
chorda tympani branch of facial nerve
afferent nerve fibres from posterior 1/3rd of tongue reaches the brainstem via what nerve?
glossopharyngeal nerve
what stimulates the salty taste?
chemical salts esp NaCl
what stimulates the sour taste?
acids which contain free hydrogen ions