Peritoneum

The peritoneum is the epithelial lining of a body cavity (coelom). In higher vertebrates, the peritoneum is the lining of the abdominal cavity in particular; the corresponding tissue in the pleural and pericardial cavities of the thorax is called the pleura and the pericardium respectively. The peritoneum is a thin layer of tissue made of flat cells.

In humans, the peritoneum stretches from the diaphragm to the pelvis and consists of the parietal peritoneum and the visceral peritoneum.

There is normally no empty space within the peritoneum. There is normally a tiny amount of peritoneal fluid but any accumulation of fluid (ascites) or gas (pneumoperitoneum) is abnormal. Inflammation of the peritoneum is peritonitis, which is usually caused by a perforation in the stomach or intestines and is a serious condition.

Table of contents

1 Structures of the abdomen and pelvis 1.1 Intraperitoneal structures 1.2 Extraperitoneal structures

Structures of the abdomen and pelvis

A listing of the major structures in the abdomen, divided into whether they are intraperitoneal or extraperitoneal.

Intraperitoneal structures

• stomach
• jejunum
• ileum
• appendix
• spleen
• transverse colon
• sigmoid colon
• in women:
  • uterus
  • fallopian tubes
  • ovaries

Extraperitoneal structures

• greater omentum
• lesser omentum
• liver
• gall bladder
• bile ducts
• Parts of the gastrointestinal tract
  • duodenum
  • pancreas
  • ascending colon
  • descending colon
  • rectum
• Major blood vessels
  • aorta
  • inferior vena cava
• adrenal glands
• kidneys
• ureters
• bladder