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the serous membrane lining the walls of the abdominal and pelvic cavities (parietal peritoneum) and investing contained viscera (visceral peritoneum), the two layers enclosing a potential space, the peritoneal cavity.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.


, pl.


(per'i-tō-nē'ŭm, -ă), [TA]
The serous sac, consisting of mesothelium and a thin external layer of irregular connective tissue, that lines the abdominopelvic cavity and covers most of the viscera contained therein; it forms two sacs: the peritoneal (or greater) sac and the omental bursa (lesser sac) connected by the omental foramen.
Synonym(s): membrana abdominis
[Mod. L. fr. G. peritonaion, fr. periteinō, to stretch over]
Farlex Partner Medical Dictionary © Farlex 2012




n. pl. peri·tonea also peri·tonaea (-tn-ē′ə)
The serous membrane that lines the walls of the abdominal cavity and folds inward to enclose the viscera.

per′i·to·ne′al adj.
per′i·to·ne′al·ly adv.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.


(per'i-tŏ-nē'ŭm, -ă) [TA]
The serous membrane, consisting of mesothelium and connective tissue, that lines the abdominal cavity and covers most of the viscera contained therein; it forms two sacs: the peritoneal (or greater) sac and the omental bursa (lesser sac), connected by the epiploic foramen.
[Mod. L. fr. G. peritonaion, fr. periteinō, to stretch over]
Medical Dictionary for the Health Professions and Nursing © Farlex 2012


(pĕr″ĭ-tō-nē′ŭm) [LL., Gr. peritonaion]
Enlarge picture
PERITONEUM: Seen laparoscopically (mag. ×½)
The largest serous membrane of the body, made up of the following five different folds: the greater omentum, lesser omentum, falciform ligament, mesentery, and mesocolon. These folds line the abdominal cavity and are reflected over the viscera. They connect organs within the abdomen together and protect and support the organs.


Diseases that affect the peritoneum can be assessed with gentle and careful percussion and palpation of the abdomen. Localized or diffuse peritonitis, for example, may be evident when the abdomen is tapped with a percussing finger (the patient will wince, guard the abdomen, and complain that the percussion is very painful); it may also be evident when the abdominal wall is gently depressed and then released (release of the examining hand causes guarding and discomfort). Fluid within the peritoneum (ascites) may be suggested by shifting dullness on percussion of the abdominal wall, or by the detection of a fluid wave when one hand depresses and releases on one side of the abdomen, while the other hand gently holds the opposite side.

See: illustration

parietal peritoneum

Peritoneum lining the abdominal walls and the undersurface of the diaphragm.

visceral peritoneum

Peritoneum that invests the abdominal organs. The peritoneum holds the viscera in place by its folds, which are called the mesentery.
Medical Dictionary, © 2009 Farlex and Partners


The double-layered, serum-secreting membrane that lines the inner wall of the ABDOMEN and covers, and to some extent supports, the abdominal organs. The fluid secreted by the peritoneum acts as a lubricant to allow free movement of organs such as the intestines. The peritoneum contains blood vessels, lymph vessels and nerves. From the Greek peri , round about, and teinein , to stretch.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005


the thin membrane of mesodermal origin that lines the body cavity covers the heart, and forms mesenteries.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005


The transparent membrane lining the abdominal cavity that holds organs such as the intestines in place.
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
The reproducibility of the method was checked by measuring 18 times the same section of peritoneum with a mean +/- SE of 25.75 +/- 0.11 [cm.sup.2] and a coefficient of variation of 1.83 %.
A complex clinical-morphological study confirmed the tumor on the peritoneum as a peritoneal leiomyomatosis with a low degree of malignancy, low expression of estrogen receptors, and high expression of progesterone receptors, which allow adequate pathogenetic hormonal therapy.
In women, the dissection starts with identification of the peritoneum over the pouch of Douglas.
However, doctors still believed the peritoneum to be the key so the process has been changed; in order to reduce the shock to the patient's body, the temperature of the chemotherapy drugs has been reduced by two degrees to 40 degrees.
When comparing CT scan findings to histopathology, 4 findings on a CT scan showed statistical significance to diagnose TB over carcinomatosis; smooth thickening of the peritoneum, abdominal mass, lymph node necrosis and high density ascitic fluid.
The 93 patients in Group A (observation group) underwent pelvic peritoneum reconstruction, whereas the pelvic floor peritoneum was not sutured in the 99 patients in Group B (control group).
The influence of traditional surgical closure of the peritoneum in CS on the development of adhesions is still unclear, especially if those adhesions could adversely affect the future reproduction after CS procedure.
All patients had ischemic changes which involved the whole bowel (stomach, small bowel, large bowel to rectum), peritoneum, and omentum (Figure 2).
The coelomic metaplasia theory states that mesothelial cells and stromata on the peritoneum and ovarian surface metamorphose into endometrium-like tissues where the endometriotic tissues occur.
MRI is the most accurate method used to determine the depth of the lesion, specifically in relation to the sheath and the peritoneum. This is an important step when the excision of the umbilical nodule is undertaken.
It is frequently located in pleural cavity, peritoneum, and pericardium.