Peritoneum
serous membrane that forms the lining of the abdominal cavity or the coelom—it covers most of the intra-abdominal (or coelomic) organs—in amniotes and some invertebrates
The peritoneum is the serous membrane forming the lining of the abdominal cavity or coelom in amniotes and some invertebrates, such as annelids. It covers most of the intra-abdominal (or coelomic) organs, and is composed of a layer of mesothelium supported by a thin layer of connective tissue. This peritoneal lining of the cavity supports many of the abdominal organs and serves as a conduit for their blood vessels, lymphatic vessels, and nerves.
The abdominal cavity (the space bounded by the vertebrae, abdominal muscles, diaphragm, and pelvic floor) is different from the intraperitoneal space (located within the abdominal cavity but wrapped in peritoneum). The structures within the intraperitoneal space are called "intraperitoneal" (e.g., the stomach and intestines), the structures in the abdominal cavity that are located behind the intraperitoneal space are called "retroperitoneal" (e.g., the kidneys), and those structures below the intraperitoneal space are called "subperitoneal" or "infraperitoneal" (e.g., the bladder).
Structure
Layers
The peritoneum is one continuous sheet, forming two layers and a potential space between them: the peritoneal cavity.
The outer layer, the parietal peritoneum, is attached to the abdominal wall and the pelvic walls. The tunica vaginalis, the serous membrane covering the male testis, is derived from the vaginal process, an outpouching of the parietal peritoneum.
The inner layer, the visceral peritoneum, is wrapped around the visceral organs, located inside the intraperitoneal space for protection. It is thinner than the parietal peritoneum.
This brief starts where responsible research should: with the source description of “Peritoneum” as serous membrane that forms the lining of the abdominal cavity or the coelom—it covers most of the intra-abdominal (or coelomic) organs—in amniotes and some invertebrates. Everything that follows is an evidence route, not borrowed authority.
Why this record matters
The subject matters to the general reference register because the source frames it as serous membrane that forms the lining of the abdominal cavity or the coelom—it covers most of the intra-abdominal (or coelomic) organs—in amniotes and some invertebrates. Its deeper value depends on whether names, dates, institutions and citations support that framing.
Named sources, stable identifiers and responsible institutions provide the strongest route from overview to verifiable evidence. The source revision retrieved here is dated Sep 24, 2026. The linked authority identifier is Q9629. The Library of Congress control number is sh85099958. 1 of 1 selected statements include explicit references; 1 carry qualifiers and 0 use preferred rank.
Overview language is designed for orientation and should not be treated as a substitute for the evidence cited beneath it. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.
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Three-step research path
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- Expand the search: follow Peritoneum primary sources, Peritoneum archive and Peritoneum research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
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This entry incorporates text from “Peritoneum” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.