Taste and Smell

Question 1

Taste

Answer 1

The sensation produced when stimuli react with receptors of taste buds - chemical reaction between stimuli and receptors

Question 2

Taste buds

Answer 2

Human tongue has 2000-8000 taste receptors - grouped on papillae - around 50 taste receptor cells within taste buds. The cells produce info about identity, concentration, and sensation of food. Also cause salivation

Question 3

5 types of taste receptors

Answer 3

sweet, sour, bitter, salty, umami

Question 4

Central Taste Pathway

Answer 4

Taste receptor cells send information to nerves V, VII, IX, X
Facial nerve VII - taste from anterior tongue and information to salivary glands
Glossopharyngeal IX - Taste from back of tongue
X Vagus nerve - muscles for voice and soft palate
Trigeminal nerve V - signals temperature and texture
These nerves go to the solitary tract, which then arrive at the ventral posterior medial nucleus of the thalamus and insula

Question 5

Primary gustatory cortex

Answer 5

Brain structure responsible for perception of taste. Two substructures: anterior insula and the frontal operculum of the frontal lobe. The pathways here are part of what decide whether to ingest or reject a food. Insula is activated in unpleasant taste.

Question 6

One-trial learning

Answer 6

After an unpleasant experience from eating a food, wolves reject the food in the future.

Question 7

From tasty to nasty

Answer 7

Regions involved in reward including striatum and midbrain VTA decrease more chocolate the subject ate.

Question 8

Supertasters

Answer 8

more taste receptor cells, can taste things intensely

Question 9

Effect of expectation on taste

Answer 9

Foods perceived as more valuable taste good and increase activity in the medial orbitofrontal cortex, an area thought to encode for pleasantness

Question 10

Ventral posterior medial nucleus

Answer 10

Receives initial information about taste from the solitary tract and projects to gustatory cortex

Question 11

Olfactory epithelium

Answer 11

A sheet of olfactory neurons which line half of the nasal cavity

Question 12

Cilia

Answer 12

Microscopic nose hairs which have receptor proteins that trap odor molecules and relay information to the brain.

Question 13

Process of smell

Answer 13

Neurons in olfactory epithelium send info thru olfactory nerve to glomeruli in the olfactory bulb. Glomeruli - way stations in pathway from nose to olfactory cortex. Synapses between the terminals of olfactory nerve and the dendrites of cells in the glomeruli. One of these cells, mitral cells, transfer information to areas in the brain such as piriform cortex, entorhinal cortex, amygdala. Bulb transmits smell info from nose to brain.

Question 14

Piriform cortex

Answer 14

Assesses and categorizes smell based on chemical structure

Question 15

Flavor

Answer 15

Flavor of many foods comes less from taste and more from smell. Flavor combines taste, smell, and texture.

Question 16

Sub-concious smell

Answer 16

Tears and sexual arousal - even if men could not tell between saltwater and women’s tears, decreased activity in hypothalamus (region involved in sexual arousal)

Question 17

Synaesthesia

Answer 17

Crossing of the senses associated with over connectivity, may relate to poor synaptic pruning