chemical senses: taste

infants- 10,000 adults- 3,000

how many taste buds to humans have?

gustatory cells (taste)

taste receptors with gustatory hairs that sense chemicals, 10 day lifespan

taste pores

chemicals pass through here, hairs microvilli extend out

supporting cells

cells that give shape to the taste bud, support and protect receptors

basal cells

stem cells that replace taste cells

papaillae

bumps on the surface of the tongue that sometimes contain taste buds but not always (4 types)

filiform papillae

small papillae, no buds, to provide friction, touch receptors present

circumvallate papillae

large papillae, only 7-12, each over 11 buds, form the V on the back to the tongue

fungiform papillae

smaller, round papillae, more abundant, 5 buds of each

foliate papillae

short vertical folded papillae on the sides of the tongue, about 20, 100 taste buds

tongue, soft palate, inner cheeks, pharynx, epiglottis

locations of taste buds

gourd shaped

shape of taste bud

sweet

taste sensation from sugars, alcohols, some amino acids, and lead

salty

taste sensation from metal ions (NaCl)

sour

taste sensation from acids (H+)

bitter

taste sensation from alkaloids (caffeines, morphine, nicotine, narangin)— we are 100x more sensitive to bitter than sour

umami

taste sensation discovered by the Japanese that comes from amino acids, especially glutamate (meats)

minty

this flavor activates cold receptors

spicy

this flavor activates heat receptors, capsacin lowers threshold

fungiform papillae

supertasters have more

decline in number

as one gets older, taste buds