Taste and Smell Flashcards

Flashcards about Taste and Smell based on lecture notes.

What is Gustation (taste)?

The detection of dissolved chemicals by receptor cells mostly located on the tongue.

What are taste buds?

Sensory organs for taste, each containing 50-100 gustatory epithelial cells (chemoreceptors).

What are papillae?

Peg-like projections on the tongue where most taste buds are found.

What are Fungiform papillae?

Scattered over the tongue surface, with 1-5 taste buds each.

What are Vallate papillae?

8-12 large papillae at the back of the tongue containing many taste buds.

What are Foliate papillae?

Located on the lateral areas of the tongue, containing many taste buds (less with age).

What are gustatory hairs?

Microvilli that project from gustatory epithelial cells into the taste pore.

What is a taste pore?

Where food and beverage dissolved in saliva enter to be tasted.

What are basal cells?

Stem cells that eventually become taste bud cells.

What is receptor potential?

A voltage shift that occurs when a chemical activates the taste receptor cell.

What causes Saltiness?

Typically from the taste of the cation Na+.

What causes Sourness?

From H+ ions that dissociate from acids (low pH).

What causes Bitterness?

Elicited by alkaloids (quinine, nicotine, caffeine, morphine, and other compounds containing nitrogen).

What causes Sweetness?

Elicited by sugars, saccharin, alcohols, and some amino acids.

What causes Umami (Savory) taste?

Elicited by amino acids.

What are the 3 Cranial nerves involved in taste?

Facial nerve (VII), Glossopharyngeal (IX), and Vagus nerve (X).

What are the major components of the Central Taste Pathways?

Gustatory nucleus in the medulla, pons to thalamus (VPM), and gustatory cortex.

What is Olfaction (Smell)?

Sensation of volatile chemicals in inspired air by the olfactory epithelium.

What is the olfactory epithelium?

Pseudostratified columnar epithelium in the roof of the nasal cavity.

What are the components of the olfactory epithelium?

Olfactory receptor cells, supporting cells, and basal cells.

What are Olfactory receptor cells?

Bipolar neurons with one dendrite and one axon that respond to odorants.

About how many different odorant receptor genes do humans have?

350

What kind of proteins are Olfactory receptor proteins?

GPCRs

What is olfactory transduction?

Olfactory receptor activation resulting in membrane depolarization.

What is the Olfactory Pathway?

Olfactory receptor cells, olfactory nerve (CN I), olfactory tract, and olfactory tubercle.

From the olfactory tubercle, where can sensory information be transmitted?

Olfactory orbitofrontal cortices, medial dorsal nucleus of thalamus, amygdala, and hippocampus.

What is a sensory map?

Arrangement of neurons that correlates with certain features of the environment