An open<unk> <unk> is the formation of cavities, which are spaces or openings in the body. This process occurs in mammalian embryos, and can also occur later on in fully developed organisms. During mammalian embryo development,<unk> is a routine process; however, the formation of cavities in fully developed organs, especially in lung tissue, is usually the sign of a severe medical condition or disease, such as tuberculosis.
Cavitation 
Edema
Regurgitation 
Atopy
Hydrodilatation
Allostasis
Ventricular remodeling
Angiopathy