Did you know that your heart is held by a little sac?

We breathe air into lungs elaborated with little sacs called alveoli.

Those little sacs are starting to show wear, but you don't know how much.

They're not passive little sacs of sugar water.

One honker brought out a little sac of paste.

They will walk through a cloud forest (thanks to a new misting system), seeing how orchids store water in little sacs in their roots.

Retroviruses, little sacs of genetic material, put out a kind of reverse code or defective blueprint causing cell overgrowth.

They carry that fluid in two little sacs under their tails, and when they jump around that's the time to run.

In its skin are cells called chromatophores, and each has little sacs of red, black and yellow pigments.

Egg have a little gas-filled sac in them too.