Definition of bulla in English:
noun (plural bullae /ˈbʊliː/)
1 Medicine A large blister containing serous fluid.
- Within three weeks, his toes turned black and serous-filled bullae erupted.
- The bullous form of impetigo presents as a large thin-walled bulla containing serous yellow fluid.
- Porphyria cutanea tarda presents with photosensitivity, skin fragility, bruising, and vesicles and bullae that can become hemorrhagic.
1.1An abnormal air-filled cavity in the lung.
- In the early stages of the disease the alveolar walls appear perfectly normal while in the later stages, fibrosis of the alveolar wall with blebs and bullae is common.
- Finding a large, ruptured emphysematous bulla makes resection mandatory.
- Examination of the surgical specimen revealed a lobe of lung with focal hemorrhage and subpleural bullae.
2 Anatomy A rounded prominence.
- The skulls of chinchilla rats have long and narrow rostra, a rounded braincase, enlarged bullae, and delicate zygomatic arches.
- The prootic is a paired bone that forms the anterior lateral face of the auditory bulla.
- The jugular process is enlarged and the tympanic projection is extended anteriorly from the ventral surface of the tympanic bulla.
3A round seal attached to a papal bull, typically one made of lead.
- One venerable conjecture was that it began as a contemptuous reference to papal edicts known as bulls (from the bulla, or seal, appended to the document).
- ‘The discovery is of considerable archaeological interest’, says Pestell. ‘Not only are bullae of this date incredibly rare, so are any seals’.
Latin, literally 'bubble'.