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Flashcards in 1.30 Chemical Senses Deck (20)
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What type of senses are smell and taste classified as?

Special Visceral Senses


What genetic components are there to why people may like or dislike some foods?

Some people have genes which allows them to taste certain flavours more intensely - e.g. dominant gene for the bitter taste in Brussel sprouts


Where can taste buds be found?

Oral cavity, pharynx and upper part of oesophagus


Which cranial nerves are responsible for taste?

VII - chordae tympani - ant. 2/3 of tongue
IX - lingual branch - post. 1/3 of tongue
X - superior laryngeal branch - epiglottis


What is the taste map myth?

All areas of the tongue can taste all flavours, however some areas are more sensitive to certain flavours - back bitter, from sweet


How many taste buds and taste cells are there on the tongue?

4000 taste buds - 30-100 taste cells


What is the function of basal cells?

Semi-differentiated - can divide to replace taste cells


Which substances (tastes) have the highest and lowest threshold?

High threshold - HCL - harmful
Low threshold - Glucose - needed


What is the bitter, sweet and umami (amino acid) taste transduction method?

G protein activated - second messenger - calcium enters and calcium acts upon vesicle (CICR) - exocytosis


What is the salt transduction method?

Na enters cell - causes depolarisation - na and ca enter cell - exocytosis


What is the acids (sour) taste transduction method?

H ions enter cell - causes depolarisation - na and ca enter cell - exocytosis


What is the gustatory pathway?

VII, IX, X - brainstem - nucleus of solitary tract - thalamus - ventroposterior - relayed gustatory cortex


What are the cell types of the found in the olfactory epithelium?

Receptor neurone - bipolar
Sustenticular cell
Basal cell
Bowman's gland secretory cells
Olfactory ensheathing cells


What is the function of vomeronasal organ in animals?

Can detect pheromones - attraction to opposite sex


What is the function of sustentacular cell?

Supporting cell for neurones and shifts mucous


What is the smell transduction method?

1. odorant binds to receptor
2. activates Golf
3. alpha subunit activated in adenylyl cyclase
4. generates cAMP from ATP
5. depolarisation and ca release
6. ca opens chloride channels


What is the function of mitral and tufted cells?

Miteal and tufted cells - send info to olfactory tract


What is the function of granular cells?

Feedback comes through these cells, these modulate and alter other cells - act upon tufted and mitral cells - desensitisation


What is the function of the periglomerular cells?

Glomeruli act upon them as well as feedback - allows cells to modulate other cells - also acts upon glomeruli


What is the olfaction pathway in the brain?

1. olfactory tract
2. lateral, primary, olfactory stria
3. anterior perforated substance
4. amygdala
5. anterioir parrahyppocampal gyrus, uncul and entorhinal, and piriform area