Gustation 9.4 Flashcards
What type of sense is gustation?
chemical
is gustation vital?
no
How does gustation increase lifespan?
It serves as protection from noxious stimuli, spoiled food, or unknow substances.
Combination of modalities
Gustation can also include smell, touch (tactile)
What are the five primary categories of gustation
- Sour [H+]
- Sweet (sugars like glucose)
- Salty (Na+)
- Umami “meaty” amino acids and glutamate
- Bitter (caffeine, morphine)
What are sensory receptors in gustatory receptors called? Where are they located?
Gustatory receptors are located on taste buds
What are the components of a taste bud?
Gustatory receptor cell with microvilli which is the site of transduction
Supporting cell
Basal (stem cell)
First order neuron
Gustatory receptors
Modified epithelial cells that synapse with first order neuron of gustatory pathway. Transduction onvloves ion channels or GPCRs (gustducin)
What is the gustatory pathway
Trasduction occurs at the gustatory microvill and invloves ion channels or GCPR (gustducin) synapses with a first order neuron and the AP is transmitted from 3 cranial nerves Facial (5), gossopharyngeal (9), and vagus (10). The first order neurons synapes in nucels of solitary tract (NTS), second order neurons synpase in the thalamus, third order neuron terminates in gustatory cortex. It is ipsilateral
Gustatory Cortex
Determines conscious awareness of taste
Discriminates different taste
Receives CNS input from limbic system and hypothalamus to link taste to emotional response
Hypogeusia
Diminished sense of taste
Linked to disorders in olfaction
Associated factors: Diabetes, Covid 19, chronic smoking
Dysgeusia
Reduced sensitivity to one or more taste categories
Presents as altered perception of one or more taste senstations
Associated factors: defieciency in zinc, vitamin B12, niacin, copper, chronic smoking
Ageusia
Complete loss of taste
Underlying causes are unknown
Associated factors: depression, anxiety, ED
