Chemosensation Flashcards
Sweet, bitter, and umami tastes are transmitted via _____ receptors.
metabotropic GPCRs
What is the receptor cell for chemmesthesis? What CN does it use?
- free nerve ending of cranial ganglion cells
- CN 5
Where is the primary sensory nucleus in the CNS for olfaction?
olfactory bulb
This is the term for the loss of taste.
Ageusia
Parosmia
Altered perception of smell in the presence of an odor, usually unpleasant
How are the neural pathways different for taste and smell?
taste has to go thru the thalamus, but smell does not
In taste, where do the thalamic neurons send their axons?
to the insular cortex
This is an altered perception of smell in the presence of an odor; usually unpleasant .
Parosmia
Salty and sour tastes are transmitted via _____ receptors.
ion channels
Hyposmia
diminished sense of smell
Taste involves stimulation of what 3 sensory systems?
- olfaction
- gustation
- chemesthesis
What are the 2 routes that odorants take into the body?
- Ortho-nasal = through nostrils
- Retro-nasal = mouth –> through the concha –> olfactory epithelium
Where are the 2nd order cells for taste?
medial part of the ventrobasal thalamus (VPMpc)
This is an altered/distorted sense of smell.
dysosmia
What is the receptor cell for taste? What CN does it use?
- a modified epi cell
- CN 7, 9, 10
Anosmia
a sudden loss of smell
What is the receptor cell for olfaction? What CN does it use?
- a cilitated, bipolar neuron
- CN1
Where is the primary sensory nucleus in the CNS for chemesthesis?
spinal trigeminal nucleus
What is the term for the diminished sense of smell?
hyposmia
Dysosmia
altered/distorted sense of smell
What is the significance of the Entorhinal cortex?
feeds into hippocampus –> storage and retrieval of memories
Olfactory axons project directly onto the ______.
- olfactory cortex
- a portion of the amygdala
A sudden loss of smell is called?
anosmia
What part of the brain gives conscious appreciation of smell?
the Orbitofrontal cortex
Ageusia
loss of taste
Anosmia can often lead to ____.
severe depression
Phantosmia
Perception of smell without an odor present
What are the 3 kinds of taste papillae? Where are they found? What CN innervates them?
- fungiform (anterior): facial- 7
- foliate (sides): facial - 7
- circumvallate (posterior): glossopharyngeal - 9
This is the perception of smell without an odor present.
Phantosmia
Where is the primary sensory nucleus in the CNS for taste?
nucleus of solitary tract
