Tentacles on the bottom of my tounge?

i noticed a few years back, little things on the bottom of my tongue, and the best word that I can think of to describe them is little tiny tentacles. they run in two parallel lines on either side of my tongue running from the bottom of my tongue to the tip, however there are only around 4, maybe 5 of these "tentacles" per side. i'd really like to know what they are called and what their purpose is. any help would be greatly appreciated.