What is a bulla?

Answer 1

A pulmonary bulla is an abnormal enlargement of alveolar space usually caused by the destruction of alveolar walls to make one space out of many smaller spaces. The bulla can be filled with air, blood or septic exudate.

Answer 2

Bulla, an amulet and worn like a locket, was given to children, at the time of birth, in ancient Rome. A bulla was worn around the neck as a locket to protect against evil spirits and forces. A bulla was made of differing substances depending upon the wealth of the family. A common substance was leather, but the richer families would have bullae of gold or silver, and poorer families' would be made of cotton.

A girl child continued to wear her bulla until the eve of her marriage, when it was removed and kept along with her childhood toys and other things. A boy used to wear a bulla until he became a Roman citizen. His bulla was carefully saved, and on some special occasions, like his becoming a general and commanding a parade, the bulla was taken out. He would wear the bulla during the ceremony to safeguard against evil forces like jealousy of men.

Bulla, or bullae which is the plural form, also refers to seals used since ancient times to show that the contents of a letter, document, bag, or other container have not been tampered with. These were made from metal (mostly lead), wax, or clay. Typically they were placed on a cord that tightly enclosed the object.