Cyst

A cyst is a closed sac having a distinct membrane and developing abnormally in a cavity or structure of the body. They can occur as a result of a developmental error in the embryo during pregnancy or they can be caused by infections. However, they sometimes arise spontaneously with no apparent cause. Cysts can often be dangerous as they may have negative effects on the nearby tissue. They may contain air, fluids, or semi-solid material.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Cystic fibrosis is an example of a genetic disorder whereby cysts develop in lung tissue and release mucus into the lungs (see Alveoli) reducing lung capacity and causing persistent coughing.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Cysts can occur anywhere in the body; however, some of the more common ones are listed here:

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

• Ganglion cyst
• Ovarian cyst
• Pilonidal cyst
• Sebaceous cyst
• Paratubal cyst

Compare a pseudocyst, which is a collection without a distinct membrane.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Membrane: A membrane is a thin, typically planar structure or material that separates two environments. Because it sits between environments or phases and has a finite volume, it can be referred to as an interphase rather than an interface. Membranes selectively control mass transport between the phases or e...

Tissue: The word tissue has several meanings:...

Air: Air is a name for the mixture of gases present in the Earth's atmosphere....