Gustation

Gustation Nerve pathway

1 impulse from brain stem 2 Medulla 3 Thalamus (post-central gyrus & insula) 4 Gustatory cortex (in parietal lobe) (paired with hearing, smell, sight to conclude taste)

What are the 5 primary taste sensations?

Bitter Sour Salty Sweet Umami

What two nerves play a role is gustation?

CN 7 - (facial nerve) for the anterior 2/3 tongue CN-9 (glossopharyngeal nerve) Posterior of 1/3 tongue (con't to CN 10 for phrayngeal wall and epiglottis)

Which cranial nerves are involved in taste?

CN VII (facial) for the anterior 2/3s of tongue; CN IX (glossopharyngeal) for the posterior 1/3 of the tongue; CN X (vagus) for the taste buds scattered over the epiglottis and pharynx.

How is taste "interpreted"?

Chemoreceptors

What is Gustation?

Comes from "gusto" taste or like Sense of taste - formal term

Taste Hairs

Dendritic ending of the gustatory cells; Project out of taste pore-; Sensory portion of receptor cells;

Four types of Papillae

Fungiform papillae Foliate Papillae Vallate papillae F.irst F.or V.ice From tip to back! Filiform are also there (they are spiky but have no role in taste!)

What are taste cells called?

Gustatory cells "liking cells" (little circles)

Fungiform Papillae

Look like fungi (mushroom) At tip of tongue 1-3 taste buds on each located at apex

Supporting cells

Look like taste cells, but have no sensory participation, innervation or synaptic vesicles.

Where are taste buds located?

On the papillae - as seen close up in circle

Where are the structures that receive taste sensations located?

Primarily on the lingual papillae - especially the circumvallate papillae.

Filiform Papillae

Spiky, no taste buds - no role in taste but TEXTURE OF FOOD most abundant papillae on tongue (make cat tongue rough for grooming)

Basal Cells of taste bud

Stem cells that multiply and replace taste cells that have died.

What are the organs responsible for gustation?

Taste buds located on the papilae

What types of cells are found in taste buds?

Taste pore Taste hairs Taste Cells Supporting cells Basal Cells

Circumvallate Papillae

The back of the tongue V-shaped Contain most of the taste buds only about 7-12 papillae but have about 250 taste buds on each!

What is the function between serous glands (watery) at the base / between the lingual papillae.

The secrete a serous (watery) solution that washes taste stimuli away from the taste pores of the taste buds. This allows you to taste subsequent stimuli. "cleansing the pallet"

What are chemoreceptors of taste?

The taste cells that are modified epithelial cells circle of location

Where are gustatory cells located?

They are located in barrel shaped accumulation of cells called taste buds. They are surrounded by supporting cells (in green)

Location of taste

Tip of tongue to sweet lateral -salty sour Back of tongue bitter

Foliate Papillae

Weakly developed in humans- at back of tongue. Most lose all tastebuds at ages 2-3 .

In which location marked on the diagram would you always expect to find a taste bud? a. lingual fold (A) b. circumvallate papilla (B) c. palatine tonsil C) d. fungiform papilla (D)

circumvallate papilla (B) As they have about 250 taste buds on each of them you would always find a taste bud! Even though fungiform have they are less 1-3 chances are "damages"

Taste pore

opening on the "free" surface of the papillae where the taste hair stick out from

The special sense of taste (gustation) is interpreted in which lobe of the cerebrum?

parietal lobe