Taste and Smell Flashcards
Gustatory system
Taste system
Papillae
Bumps on tounge NOT taste buds
Tastants
Excite receptor cells on the tounge, produce the sensation of taste
Taste buds
Contain taste receptor cells built into the walls of the papillae
Taste receptor cells
Have microvill which contact the tastants
What is the order
Papillae> Taste Bud> Taste cells
What are the 5 different tastes ?
Sweet, Salty, Sour, Bitter, Umami
Circumvallate Papillae
Found on the back of the tounge and sensitive to bitter flavors
Foliate Papillae
Found on the sides of the tounge, near the back and sensitive to sour tastes
Fungiform Papillae
Found on the tip and sides of the tounge, sensitive to sweet, salty, and umami flavors
Flavor
The perception of taste
Sweet, bitter, and umami equal
G- protein-coupled receptors that result in activation of second messengers.
Salty and sour equal
Ions that activate ion channels
The gustatory system parts
1) Three cranial nerves (facial, glossopharyngeal, vagus)
2) Brainstem nuclei
3) Thalamus
4) Gustatory cortex
Pattern coding
tastes may be based on temporal patterns
of action potentials
What is the only sense that bypasses the thalamus?
Olfaction
olfactory epithelium
Where the sense of smell starts, with receptor neurons in the nose
What are the three types of cells in the epithelium
- Supporting cells
- Basal cells
- Receptor neurons
Odor receptor neurons
CAN fire action potentials
Steps of the Olfactory System
1.Odorant receptors on
the cilia of the ORN
can interact with
odorants in the air.
2.Odorants bind to
specific receptors
- Binding causes
depolarization of the
cilia membrane
Where do odor receptor neurons end?
Olfactory bulb
What is the olfactory bulb organized into?
glomeruli—roughly spherical units
Mitral cells
relay neurons,
also known as projection
neurons, that convey and refine
information after initial sensory
input has been detected and
relayed to the olfactory bulb
Are olfactory receptor neurons regenerative ?
Yes
orbitofrontal cortex (OFC)
Where the brain integrates taste and smell information
Anosmias
“odor blindnesses,”
meaning they can’t detect certain
smells.
Cilia
tiny, hair-like structures in the nose that move mucus and trapped particles out of the body
Where are the mitral cells located ?
Located in the olfactory bulb of the brain, specifically within a layer called the mitral cell layer, where they receive signals from olfactory receptor neurons through synapses in structures called glomeruli; essentially, they are the primary projection neurons of the olfactory bulb responsible for processing smell information
