AP 227 - Lab Review sheet #26 Special Senses, Olfaction, and Taste
Describe the cellular composition and the location of the olfactory epithelium.
Receptor cells (bipolar neurons) surrounded
by supporting cells. 1″ square area on roof of nasal cavity on each side of nasal septum.
How and why does sniffing improve your sense of smell?
Draws air superiorly into contact with the olfactory mucosa. (Most
air entering the nasal passages passes inferior to the receptors.)
Name five sites where receptors for taste are found, and circle the predominant site.
tongue papillae, epiglottis, pharynx
soft palate, cheek mucosa
Describe the cellular makeup and arrangement of a taste bud. (Use a diagram, if helpful.)
A structure consisting of centrally
located gustatory (receptor) cells surrounded by supporting cells.
Taste and smell receptors are both classified as
Taste and smell receptors are both classified as CHEMORECEPTORS
because they both respond to chemicals in aqueous solution
Why is it impossible to taste substances with a dry tongue?
Substances must be in aqueous solution.
The basic taste sensations are mediated by specific chemical substances or groups. Name them for the following taste modalities.
SALT: Influx of Na+, SOUR: H+ plus blockage of K+ or Na+ channels, BITTER: G protein gustducin causing increased intracellular Ca2+, SWEET: G protein gustducin causing K+ channels to close, UMAMI: The amino acid glutamate.
Name three factors that influence our appreciation of foods. Substantiate each choice with an example from the laboratory
Smell, texture, temperature
(you must state your conclusions as to why)
Which of the factors chosen is most important?
Expand on your explanation and choices by explaining why a cold, greasy hamburger is unappetizing to most people.
When hot, a hamburger is “juicy” and has an enticing aroma. When cold, the fat congeals, giving the hamburger a greasy taste and
How palatable is food when you have a cold?
It's not. Smell is half of taste, when you have clogged nasal passages, you lack this added sensory input.
In your opinion, is olfactory adaptation desirable?
Yes. Continuous unimportant (unchanging) olfactory stimuli would be distracting and (probably) irritating.