Taste and smell Flashcards
What is the point of taste and smell?
Detect if food is good to eat
Influence flow of digestive juices
What is gustation?
Sense of taste
What is the organ of taste?
Taste buds
Describe a taste bud
Sensory and support cells arranged in segments like an orange
How long do taste receptor cells last for?
~10 days
Where can taste buds be found?
tongue, pharynx, palate and epiglottis
Where are most taste buds found?
Papilla
What are the 4 forms of papillae humans have?
Filiform- string like and do not contain tastebuds
Foliate
Fungiform
Vallate
What nerves convey taste?
VNII- Anterior 2/3
CNIX- Posterior 1/3
CNX- Everywhere that’s not the tongue
What are the 5 main tastes and their stimuli?
Salty- NaCL Sour- H+ Sweet- Glucose Bitter- Alkaloids etc Umami- AA like glutamate
What is ageusia?
Loss of taste
What can cause ageusia?
Nerve damage
Inflammation
Some endocrine disorders
What is hypogeusia?
Reduced taste
What can cause hypogeusia?
Chemotherapy
Some medications
What is dysgeusia?
Distortion of taste
What can cause dysgeusia?
Glossitis; gum infections; tooth decay; reflux; upper respiratory infections; medications; neoplasms; chemotherapy; zinc deficiency
What is olfaction?
Sense of smell
Where is smell sensed?
Olfactory mucosa
What cells are found in the olfactory mucosa?
Basal cells
Supporting cells
Olfactory receptor cells
What are olfactory receptor cells?
Specialised endings of renewable afferent neurons
What are odorants?
Smell molecules that bind to cilia
How long to olfactory receptors last.
~2 months
What are basal cells used for?
Precursors for new olfactory receptors
Where do olfactory nerves pass through?
Cribriform plate
What is anosmia?
Loss of smell
What can cause anosmia?
Viruses
Allergy
Nasal polyps
Head injury
What is hyposmia?
Reduced sense of small
What can cause hyposmia?
Similar to anosmia and Parkinson’s
What is dysosmia?
Altered sense of smell
What can cause dysosmia?
Hallucination of smell
Different interpretation
