Perforation

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perforation

[‚pər·fə′rā·shən]
(ordnance)
Passage of a missile completely through an object.
(science and technology)
Any hole made by boring, punching, or piercing.

Perforation

 

(1) In botany, an opening in the cell membrane of a vessel in vascular plants. Water passes freely through the perforations and into the vessels. The perforations may be on the lateral and transverse walls of the cells. If a perforation is single, it is called a simple perforation (in the vessels of oaks and herbs). Multiple perforations are arranged in parallel series (scalariform perforations), in an irregular network (reticulate perforations), or as a group of approximately circular holes (foraminate perforations). Ferns have scalariform perforations, ivies reticulate perforations, and ephedras foraminate perforations.

(2) In medicine, the penetration of the wall of a hollow or tubular organ, for example, the intestine.


Perforation

 

in medicine, an opening or hole in the wall of a cavitary or tubular organ, as a result of which the cavity of the organ communicates with surrounding cavities or tissues.

Perforation may be caused by intrusion of a foreign body from the lumen of an organ (for example, perforation of the esophagus by a swallowed bone) or externally (a penetrating knife or bullet wound). It may also be caused by disruption of all layers of an organ by a pathological process, for example, perforation of an ulcer or tumor of the stomach or intestine or perforation of the vermiform appendix or the gallbladder with gangrenous appendicitis or cholecystitis.

When there is a perforation, the contents of a hollow organ, by penetrating surrounding tissue (periesophageal or perirectal) or the abdominal cavity, cause development of a rapidly progressing purulent inflammatory process called mediastinitis, paraproctitis, or peritonitis. Treatment consists in emergency surgery.

References in periodicals archive ?
And the perforated edges create the impression of a rosary beads surround.
The leaves are put in a white cup with perforated edges on one side of the cup's rim.
The two cases will be joined by perforated edges that make for easy separation.
The vinyl shades have perforated edges so the user can tear off the shade to fit the proper window size.
In the form-fill-seal process, the web is folded in half, joining the two perforated edges on each side of the pouch top, which are then sealed together.
Thomas says: "Can you please put your column on the left-hand side of the paper, Tam, as that makes it easier to read when I'm sitting on the toilet?" Still, makes a pleasant change from one or two other readers asking if my page could have perforated edges.