Module 3.3 Olfactory and Gustatory System Flashcards
Olfactory nerves contain what type of receptor cells (neurons)
?
Bipolar receptor cells
The olfactory nerves travel through what bone?
Ethmoid (cribriform plate)
What is the order of the olfactory nerve pathway?
Olfactory nerves → olfactory bulbs → olfactory tracts → primary olfaction area of temporal lobes
What is smell?
Smell is defined as a combination of a limited number of primary odors that are detectable by the brain.
What is the anatomical word for taste?
Gustation (gustatory system)
True or false: The apex of the tongue is located on the anterior aspect of the mouth.
True
What is a bolus?
A compact mass of food, prepared by the tongue and teeth.
What type of papillae contain taste buds?
Circumvallate and fungiform papillae both contain taste buds
True or false: Gustatory cells are the chemoreceptors of the taste buds.
True
What is the purpose of basal cells?
Basal cells serve as stem cells, which divide and differentiate into new supporting cells which then form new gustatory cells.
True or false: The taste pathway sends signals via only one cranial nerve to the brain.
False (two nerves - facial and glossopharyngeal)
What is anosmia?
The loss of smell
What activates olfactory receptors?
Airborne chemical substances dissolved in fluid on the surface of nasal mucous membranes
What are the olfactory bulbs?
paired masses of gray matter, Dendrites of the olfactory nerves terminate in these and olfactory nerve axons synapse with other cell bodies of the olfactory pathway.
What are the olfactory tracts?
Formed by the axons traveling together from the olfactory bulbs and carry information to the temporal lobes.
How many primary odors are there? And what are they?
7 and they are floral, musky, ethereal, camphorates, peppermint, pungent and putrid.
How are gustatory receptors activated?
Chemical substances dissolved in saliva.
What is the tongue responsible for?
Gripping food and repositioning it between the teeth to form bolus and push it back to the pharynx to begin process of swallowing.
What is the function of the taste bud’s supporting cells?
Separate the taste receptors cells from one another and form bulk of taste bud.
What other receptors are found in the mouth that influence taste perception?
Nociceptors and thermoreceptors.
What is the taste pathway?
Food chemicals –> gustatory hairs –> (action potential dendrites) gustatory cells –> afferent fibers through the CN VII and CN IX –> thalamus –> parietal lobe.
Which nerves carry taste information from what areas of the tongue?
Facial nerve - anterior two-thirds of the tongue, and the glossopharyngeal nerve - posterior one-third of the tongue.
How many primary tastes are there? And what are they called?
5 and they are sweet, salty, sour, bitter, and savory (umami).
Examples of what produces sweet taste?
Sugars and some amino acids.
Examples of what produces salty taste?
Many metal salts, especially NaCl.
Examples of what produces sour taste?
Acids like acetic acid (in vinegar).
Examples of what produces bitter taste?
Many drugs like aspirin.
Examples of what produces savory taste?
Certain amino acids and is found in many foods like fish, ripe tomatoes, aged cheeses, and soy sauce.
What is the loss of taste called?
Ageusia.
What could be a cause of anosmia?
Common after TBI (temporary or permanent depending on the severity of the injury and what part of the pathway was damaged). Gradual onset could be explained by e.g. growing brain tumor that blocks the olfactory pathway.
What could cause ageusia?
Obstructed olfactory receptors by nasal congestion or other factors, (taste dulled or completely lost) other factors, such as TBI or a brain tumor, or damaged taste pathway.
What is an example of an ethereal smell?
dry-cleaning fluid
What is an example of a pungent smell?
acetic acid (vinegar)
What is an example of a putrid smell?
rotten eggs or decaying organic matter
What is an example of a camphorate smell?
mothballs or camphor
