Crested Geckos have two small sacs for calcium on the roof of their mouths.

The gallbladder is a small sac found just under the liver.

At the same time, the bottom layer forms a small sac.

Alveoli are the small sacs in the lungs that exchange oxygen with the blood.

These are small sacs in the walls of the esophagus or the throat.

Remove and discard the small sac near the eyes and the intestine through the middle of the tail.

Remove and discard small sacs near the eyes.

He held up a small sac, like a hot-water bottle with straps.

The small sac inside the blastocyst begins producing red blood cells.

Afterwards, the female carries the eggs in two small sacs on her body.