exam 4 gustafactory

gustation

process by which taste buds on the tongue and other areas of the mouth detect chemicals in food and drinks, allowing us to perceive flavors such as sweet, sour, salty, bitter, and umami (savory)

Fungiform Papillae location

Scattered across the front and sides of the tongue.

Fungiform Papillae function

Primarily involved in detecting sweet, salty, and sour tastes. Due to their location, they’re involved in initial taste detection when food first enters the mouth

Each fungiform papilla contains a few taste buds (usually 3-5)

Fungiform Papillae appearance

Small, mushroom-shaped, and visible as tiny red dots

Foliate Papillae location

On the sides and towards the back of the tongue.

Foliate Papillae appearance

Leaf-shaped folds or ridges.

Foliate Papillae function

Sensitive to sour tastes and involved in tasting food as it moves toward the back of the tongue. Foliate papillae are especially active in infants and children and may play a lesser role in adults

Contains many taste buds in each fold, potentially hundreds

Circumvallate Papillae location

Arranged in a V-shape at the very back of the tongue.

Circumvallate Papillae appearance

Large and dome-shaped, with a “moat” surrounding each papilla

Circumvallate Papillae function

Particularly sensitive to bitter tastes, which may help detect potentially harmful substances before swallowing. The location allows them to help detect taste as food is about to be swallowed

Each circumvallate papilla contains hundreds of taste buds

Filiform Papillae location

Spread across most of the tongue’s surface.

Filiform Papillae function

Primarily mechanical, aiding in texture sensation and helping to move food around in the mouth. They’re also involved in sensing temperature and texture, which contribute to the overall experience of food

and do not contain taste buds.

Filiform Papillae appearance

Thin, cone-shaped structures that give the tongue a rough texture

What's in the BUD

Gustatory (Taste) Receptor Cells: These are the actual receptor cells that detect taste stimuli. They have microvilli (taste hairs) that extend into a small opening called the taste pore.
2. Supporting Cells: These cells provide structural and metabolic support to the gustatory
cells but don’t detect taste themselves.
3. Basal Cells: Stem cells at the base of the taste bud that divide and differentiate into new
gustatory cells, replacing old ones as they die.
4. Taste Pore: A small opening at the surface of the taste bud where the taste cells’
microvilli are exposed to dissolved chemicals in food.

types of gustatory receptor cells

sweet, sour, bitter, umami, and salty.

sweet

Stimulus: Sugars and other carbohydrates.
Function: Detects sweetness, which is usually associated with energy-rich foods

sour

Stimulus: Hydrogen ions from acidic foods (like lemon).
Function: Helps detect the acidity of foods, which may indicate spoilage

salty

Stimulus: Sodium ions (from salt).
Function: Helps the body detect essential minerals and maintain electrolyte balance

bitter

Stimulus: Various compounds, often from plants (e.g., caffeine, certain plant toxins).
Function: Often signals potentially harmful or toxic substances, which is why bitterness can be
aversive

umami

Stimulus: Glutamate (amino acids found in protein-rich foods like meat and cheese).
Function: Signals protein-rich foods, which are essential for growth and repair.

amygdala (hypothalamus)

involved in emotional processing of smells

trigeminal nerve

controls chewing muscles and feels touch, pain, and temperature on the face.

Vagus Nerve

controls muscles for talking and swallowing and helps regulate heart rate, digestion, and breathing.

facial nerve

controls facial expressions and carries taste from the front 2/3 of the tongue.

accessory nerve

controls neck and shoulder muscles, like turning your head and shrugging.

Glossopharyngeal nerve

helps with swallowing, makes saliva, and carries taste from the back 1/3 of the tongue.

The gustatory pathway involves all except:

Thalamus Limbic system Basal nuclei Gustatory cortex

Thalamus
Limbic system

Basal nuclei

Gustatory cortex

Gustatory receptors send signals to the brain via

3 cranial nerves