Peritoneum

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Peritoneum

In higher vertebrate

Vertebrate

Vertebrates are members of the subphylum Vertebrata, chordates with Vertebras or Vertebral columns. The grouping sometimes includes the hagfish, which have no vertebrae, but are genetically quite closely related to lampreys, which do have vertebrae....
s, the peritoneum is the serous membrane

Serous membrane

In anatomy, a serous membrane is a smooth Mesothelium consisting of a thin layer of Cell which excrete serous fluid. Serous membranes line and enclose several body cavities, known as serous cavities, where they secrete a lubricating fluid which reduces friction from muscle movement....
that forms the lining of the abdominal cavity

Abdomen

In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity....
— it covers most of the intra-abdominal organs. It is composed of a layer of mesothelium

Mesothelium

The mesothelium is a membrane that forms the lining of several body cavities: the pleura , peritoneum and pericardium . Mesothelial tissue also surrounds the male internal reproductive organs and covers the internal reproductive organs of women ....
supported by a thin layer of connective tissue

Connective tissue

Connective tissue is a form of fibrous biological tissue.It is one of the four types of tissue in traditional classifications .Collagen is the main protein of connective tissue in animals and the most abundant protein in mammals, making up about 25% of the total protein content....
. The peritoneum both supports the abdominal organs and serves as a conduit

Conduit

A conduit is a general term for a means of conveying something from one location to another or between persons.Examples of conduits:* Waterways ...
for their blood

Blood

Blood is a specialized bodily fluid that delivers necessary substances to the body's Cell s ? such as nutrients and oxygen ? and transports waste products away from those same cells....
and lymph

Lymph

Lymph is the fluid that is formed as the interstitial fluid. It enters the lymph vessels by filtration. The lymph then travels to at least one lymph node before emptying ultimately into the right or the left subclavian vein, where it mixes back with blood....
vessels and nerves.

abdominal cavity (the space bounded by the vertebrae, abdominal muscles, diaphragm and pelvic floor) should not be confused with the intraperitoneal space (located within the abdominal cavity, but wrapped in peritoneum).

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Encyclopedia

In higher vertebrate

Vertebrate

Serous membrane

Abdomen

Mesothelium

Connective tissue

Conduit

A conduit is a general term for a means of conveying something from one location to another or between persons.Examples of conduits:* Waterways ...
for their blood

Blood

Blood is a specialized bodily fluid that delivers necessary substances to the body's Cell s ? such as nutrients and oxygen ? and transports waste products away from those same cells....
and lymph

Lymph

Structure

Layers

The abdominal cavity (the space bounded by the vertebrae, abdominal muscles, diaphragm and pelvic floor) should not be confused with the intraperitoneal space (located within the abdominal cavity, but wrapped in peritoneum). For example, a kidney is inside the abdominal cavity, but is retroperitoneal.

Although they ultimately form one continuous sheet, two types or layers of peritoneum and a potential space between them are referenced:

The outer layer, called the parietal peritoneum, is attached to the abdominal wall.
The inner layer, the visceral peritoneum, is wrapped around the internal organs that are located inside the intraperitoneal cavity.
The potential space between these two layers is the peritoneal cavity
Peritoneal cavity

The peritoneal cavity is a potential space between the parietal peritoneum and visceral peritoneum. It is one of the spaces derived from the coelomic cavity of the embryo, the others being the pleural cavities and the pericardial cavity....
; it is filled with a small amount (about 50 ml) of slippery serous fluid
Serous fluid

In physiology, the term serous fluid is used for various bodily fluids that are typically pale yellow and transparent, and of a benign nature, that fill the inside of body cavities....
that allows the two layers to slide freely over each other.
The term mesentery
Mesentery

In anatomy, the mesentery is the double layer of peritoneum that suspends the jejunum and ileum from the posterior wall of the abdomen. Its meaning, however, is frequently extended to include double layers of peritoneum connecting various components of the abdominal cavity....
is often used to refer to a double layer of visceral peritoneum. There are often blood vessels, nerves, and other structures between these layers. It should be noted that the space between these two layers is technically outside of the peritoneal sac, and thus not in the peritoneal cavity.

Subdivisions

There are two main regions of the peritoneum, connected by the epiploic foramen:

the greater sac
Greater sac

In human anatomy, the greater sac, also known as the general cavity or peritoneum of the peritoneal cavity proper, is the cavity in the abdomen that is inside the peritoneum but outside of the lesser sac....
(or general cavity of the abdomen), represented in red in the diagrams above.
the lesser sac
Lesser sac

The lesser sac, also known as the omental bursa, is the cavity in the abdomen that is formed by the lesser omentum and greater omentum. Usually found in mammals, it is connected with the greater sac via the epiploic foramen ....
(or omental bursa), represented in blue. The lesser sac is divided into two "omenta":

The lesser omentum
Lesser omentum

The lesser omentum is the double layer of peritoneum that extends from the liver to the lesser curvature of the stomach and the start of the duodenum....
(or gastrohepatic) is attached to the lesser curvature of the stomach
Lesser curvature of the stomach

The lesser curvature of the stomach, extending between the cardiac and pyloric orifices, forms the right or posterior border of the stomach.It descends as a continuation of the right margin of the esophagus in front of the fibers of the right crus of the diaphragm, and then, turning to the right, it crosses the first lumbar vertebra and end...
and the liver
Liver

The liver is a vital organ present in vertebrates and some other animals; it has a wide range of functions, a few of which are detoxification, protein synthesis, and production of biochemicals necessary for digestion....
.
The greater omentum
Greater omentum

The greater omentum is a large fold of peritoneum that hangs down from the stomach, and extends from the stomach to the posterior abdominal wall after associating with the transverse colon....
(or gastrocolic) hangs from the greater curve of the stomach and loops down in front of the intestines before curving back upwards to attach to the transverse colon
Colon (anatomy)

The colon is the last portion of the digestive system in most vertebrates; it extracts water and salt from feces before they are defecation from the body....
. In effect it is draped in front of the intestines like an apron and may serve as an insulating or protective layer.

The mesentery

Mesentery

In anatomy, the mesentery is the double layer of peritoneum that suspends the jejunum and ileum from the posterior wall of the abdomen. Its meaning, however, is frequently extended to include double layers of peritoneum connecting various components of the abdominal cavity....
is the part of the peritoneum through which most abdominal organs are attached to the abdominal wall and supplied with blood

Blood

Blood is a specialized bodily fluid that delivers necessary substances to the body's Cell s ? such as nutrients and oxygen ? and transports waste products away from those same cells....
and lymph

Lymph

STRUCTURE	FROM	TO	CONTAINS >- \|	OMENTA Omentum Omentum can refer to two different components of the peritoneum:* greater omentum* lesser omentum...			- \| dorsal mesentery Dorsal mesentery The portion of mesentery attached to the greater curvature of the stomach is named the dorsal mesentery , and the part which suspends the Colon is termed the mesocolon....	* greater omentum Greater omentum The greater omentum is a large fold of peritoneum that hangs down from the stomach, and extends from the stomach to the posterior abdominal wall after associating with the transverse colon....	greater curvature of stomach Stomach In most mammals, the stomach is a hollow muscular organ of the gastrointestinal tract involved in the second phase of digestion, following mastication.... (and spleen Spleen The spleen is an organ found in all vertebrate animals. In humans, the spleen is located in the abdomen of the body, where it functions in the destruction of redundant red blood cells, and holds a reservoir of blood.... )		- \| dorsal mesentery	gastrosplenic ligament Gastrosplenic ligament The gastrosplenic ligament** is part of the greater omentum.Embryonically the gastrosplenic ligament is derived from the dorsal mesogastrium....	stomach Stomach In most mammals, the stomach is a hollow muscular organ of the gastrointestinal tract involved in the second phase of digestion, following mastication....	spleen Spleen The spleen is an organ found in all vertebrate animals. In humans, the spleen is located in the abdomen of the body, where it functions in the destruction of redundant red blood cells, and holds a reservoir of blood....	short gastric artery, left gastro-omental artery Left gastro-omental artery The left gastro-omental artery , the largest branch of the splenic artery, runs from left to right about a finger?s breadth or more from the greater curvature of the stomach, between the layers of the greater omentum, and anastomoses with the right gastroepiploic.... \|- \| dorsal mesentery	gastrophrenic ligament Gastrophrenic ligament The postero-inferior surface of the stomach is covered by peritoneum, except over a small area close to the cardiac orifice; this area is limited by the lines of attachment of the gastrophrenic ligament**, and lies in apposition with the Thoracic diaphragm, and frequently with the upper portion of the left suprarenal gland....	stomach Stomach In most mammals, the stomach is a hollow muscular organ of the gastrointestinal tract involved in the second phase of digestion, following mastication....	diaphragm Thoracic diaphragm In the anatomy of mammals, the thoracic diaphragm is a sheet of muscle extending across the bottom of the ribcage. The diaphragm separates the thoracic cavity from the abdominal cavity and performs an important function in Respiration ....	- \| dorsal mesentery	gastrocolic ligament Gastrocolic ligament The gastrocolic ligament** is a portion of the greater omentum connecting to the transverse colon.External links...	stomach Stomach In most mammals, the stomach is a hollow muscular organ of the gastrointestinal tract involved in the second phase of digestion, following mastication....	transverse colon Transverse colon The transverse colon the longest and most movable part of the Colon , passes with a downward convexity from the right hypochondrium region across the abdomen, opposite the confines of the epigastric and umbilical zones, into the left hypochondrium region, where it curves sharply on itself beneath the lower end of the spleen, forming the splen...	- \| dorsal mesentery	splenorenal ligament Splenorenal ligament The splenorenal ligament** , is derived from the peritoneum, where the wall of the general peritoneal cavity comes into contact with the omental bursa between the left kidney and the spleen; the lienal vessels pass between its two layers....	spleen Spleen The spleen is an organ found in all vertebrate animals. In humans, the spleen is located in the abdomen of the body, where it functions in the destruction of redundant red blood cells, and holds a reservoir of blood....	kidney Kidney The kidneys are Organ that have numerous biological roles. Their primary role is to maintain the homeostasis balance of bodily fluids by filtering and secreting Metabolomics#Metabolitess and minerals from the blood and excreting them, along with water , as urine....	splenic artery Splenic artery In anatomy, the splenic artery is the blood vessel that supplies oxygenated blood to the spleen. It branches from the celiac artery, and follows a course superior to the pancreas.... , tail of pancreas Tail of pancreas The tail of the pancreas, located anatomically left near the hilum of the spleen, is not simply an anatomical distinction. The tail is the only part of the pancreas which contains PP cell, which are responsible for secreting pancreatic polypeptide to coordinate exocrine and islet enzyme release.... \|- \| ventral mesentery Ventral mesentery Ventral mesentery is the part of the peritoneum closest to the navel....	* lesser omentum Lesser omentum The lesser omentum is the double layer of peritoneum that extends from the liver to the lesser curvature of the stomach and the start of the duodenum....	lesser curvature of the stomach Stomach In most mammals, the stomach is a hollow muscular organ of the gastrointestinal tract involved in the second phase of digestion, following mastication.... (and duodenum Duodenum The duodenum is the first section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms anterior intestine or proximal intestine may be used instead of duodenum.... )		- \| ventral mesentery	** hepatogastric ligament Hepatogastric ligament The cranial part of the lesser omentum is formed by the hepatogastric ligament , extending between the liver and stomach. The ligament itself consists of a dense cranial portion and the caudal portion ....	stomach Stomach In most mammals, the stomach is a hollow muscular organ of the gastrointestinal tract involved in the second phase of digestion, following mastication....	liver Liver The liver is a vital organ present in vertebrates and some other animals; it has a wide range of functions, a few of which are detoxification, protein synthesis, and production of biochemicals necessary for digestion....	- \| ventral mesentery	hepatoduodenal ligament Hepatoduodenal ligament The hepatoduodenal ligament** is the portion of the lesser omentum extending between the porta hepatis of the liver and the first part of the duodenum....	duodenum Duodenum The duodenum is the first section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms anterior intestine or proximal intestine may be used instead of duodenum....	liver Liver The liver is a vital organ present in vertebrates and some other animals; it has a wide range of functions, a few of which are detoxification, protein synthesis, and production of biochemicals necessary for digestion....	hepatic artery proper Hepatic artery proper The hepatic artery proper , arises from the common hepatic artery and runs alongside the portal vein and the common bile duct to form the portal triad.... , hepatic portal vein Hepatic portal vein The hepatic portal vein is a vein in the abdominal cavity that drains blood from the gastrointestinal tract and spleen. It is usually formed by the confluence of the superior mesenteric vein and splenic veins, and also receives blood from the inferior mesenteric vein, gastric vein, and cystic veins.... , bile duct Bile duct A bile duct is any of a number of long tube-like structures that carry bile.Bile, required for the digestion of food, is excreted by the liver into passages that carry bile toward the hepatic duct, which joins with the cystic duct to form the common bile duct, which opens into the intestine.... \|- \|	MESENTERIES			- \| dorsal mesentery	* Mesentery proper	small intestine Small intestine In vertebrates, including mammals, reptiles, birds, and bony fish, the small intestine is the part of the gastrointestinal tract following the stomach, and is where the vast majority of digestion takes place.... – jejunum Jejunum The jejunum is the middle section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms middle intestine or mid-gut may be used instead of jejunum.... and ileum Ileum The ileum is the final section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms posterior intestine or distal intestine may be used instead of ileum....	posterior abdominal wall	superior mesenteric artery Superior mesenteric artery See also: Superior Mesenteric Artery SyndromeIn human anatomy, the superior mesenteric artery arises from the anterior surface of the abdominal aorta, just inferior to the origin of the celiac artery, and supplies the intestine from the lower part of the duodenum through two-thirds of the transverse colon, as well as the pancreas.... \|- \| dorsal mesentery	* transverse mesocolon Transverse mesocolon The transverse mesocolon is a broad, meso-fold of peritoneum, which connects the transverse colon to the posterior wall of the abdomen.It is continuous with the two posterior layers of the greater omentum, which, after separating to surround the transverse colon, join behind it, and are continued backward to the vertebral column, where they...	transverse colon Transverse colon The transverse colon the longest and most movable part of the Colon , passes with a downward convexity from the right hypochondrium region across the abdomen, opposite the confines of the epigastric and umbilical zones, into the left hypochondrium region, where it curves sharply on itself beneath the lower end of the spleen, forming the splen...	posterior abdominal wall	middle colic \|- \| dorsal mesentery	* sigmoid mesocolon Sigmoid mesocolon The sigmoid mesocolon is the fold of peritoneum which retains the sigmoid colon in connection with the pelvic wall.Its line of attachment forms a V-shaped curve, the apex of the curve being placed about the point of division of the left common iliac artery....	sigmoid colon	pelvic wall	sigmoid arteries Sigmoid arteries The sigmoid arteries, two or three in number, run obliquely downward and to the left behind the peritoneum and in front of the Psoas major, ureter, and internal spermatic vessels.... \|- \| dorsal mesentery	* mesoappendix Mesoappendix The mesoappendix is the portion of the mesentery connecting the ileum to the Vermiform appendix. It may extend to the tip of the appendix. It encloses the appendicular artery and vein, as well as lymphatic vessels, nerves, and often a lymph node....	mesentery of ileum Ileum The ileum is the final section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms posterior intestine or distal intestine may be used instead of ileum....	appendix Appendix Appendix, from the Latin word of the same name, may refer to an Index / Bibliography.* In book design, an appendix is a reference section at the end of a book ...	appendicular artery Appendicular artery The appendicular artery, also appendiceal artery, descends behind the termination of the ileum and enters the mesenteriole of the vermiform process; it runs near the free margin of this mesenteriole and ends in branches which supply the vermiform process.... \|- \|	OTHER LIGAMENTS AND FOLDS			- \| ventral mesentery	* falciform ligament Falciform ligament The falciform ligament is a broad and thin antero-posterior peritoneal fold, falciform in shape, its base being directed downward and backward, its apex upward and backward....	liver Liver The liver is a vital organ present in vertebrates and some other animals; it has a wide range of functions, a few of which are detoxification, protein synthesis, and production of biochemicals necessary for digestion....	thoracic diaphragm Thoracic diaphragm In the anatomy of mammals, the thoracic diaphragm is a sheet of muscle extending across the bottom of the ribcage. The diaphragm separates the thoracic cavity from the abdominal cavity and performs an important function in Respiration .... , anterior abdominal wall	round ligament of liver Round ligament of liver In anatomy, the round ligament of liver is a degenerative string of tissue that exists in the free edge of the falciform ligament of the liver.... , paraumbilical veins Paraumbilical veins In the course of the ligamentum teres of the liver and of the middle umbilical ligament, small veins are found which establish an anastomosis between the veins of the anterior abdominal wall and the Hepatic portal vein, hypogastric, and iliac veins.... \|- \| left umbilical vein Umbilical vein The umbilical vein is a blood vessel present during fetal development that carries oxygenated blood from the placenta to the growing fetus....	* round ligament of liver Round ligament of liver In anatomy, the round ligament of liver is a degenerative string of tissue that exists in the free edge of the falciform ligament of the liver....	liver Liver The liver is a vital organ present in vertebrates and some other animals; it has a wide range of functions, a few of which are detoxification, protein synthesis, and production of biochemicals necessary for digestion....	umbilicus Umbilicus Umbilicus may refer to:*Umbilicus , a feature of gastropod, Nautilus and Ammonite shell anatomy*Navel, a synonym for the navel or belly button....	- \| ventral mesentery	* coronary ligament Coronary ligament The coronary ligament of the liver refers to parts of the peritoneal reflections that hold the liver to the inferior surface of the thoracic_diaphragm....	liver Liver The liver is a vital organ present in vertebrates and some other animals; it has a wide range of functions, a few of which are detoxification, protein synthesis, and production of biochemicals necessary for digestion....	thoracic diaphragm Thoracic diaphragm In the anatomy of mammals, the thoracic diaphragm is a sheet of muscle extending across the bottom of the ribcage. The diaphragm separates the thoracic cavity from the abdominal cavity and performs an important function in Respiration ....	- \| ductus venosus Ductus venosus In the fetus, the ductus venosus shunts a significant majority of the blood flow of the umbilical vein directly to the inferior vena cava. Thus, it allows oxygenated blood from the placenta to bypass the liver....	* ligamentum venosum Ligamentum venosum The ligamentum venosum is the fibrous remnant of the ductus venosus of the fetal circulation. Usually, it is attached to the left branch of the portal vein within the porta hepatis of the liver....	liver Liver The liver is a vital organ present in vertebrates and some other animals; it has a wide range of functions, a few of which are detoxification, protein synthesis, and production of biochemicals necessary for digestion....	liver Liver The liver is a vital organ present in vertebrates and some other animals; it has a wide range of functions, a few of which are detoxification, protein synthesis, and production of biochemicals necessary for digestion....	- \|	* phrenicocolic ligament Phrenicocolic ligament A fold of peritoneum, the phrenicocolic ligament, is continued from the left colic flexure to the thoracic diaphragm opposite the tenth rib and eleventh ribs; it passes below and serves to support the spleen, and therefore has received the name of sustentaculum lienis....	left colic flexure	thoracic diaphragm Thoracic diaphragm In the anatomy of mammals, the thoracic diaphragm is a sheet of muscle extending across the bottom of the ribcage. The diaphragm separates the thoracic cavity from the abdominal cavity and performs an important function in Respiration ....	- \| ventral mesentery	* left triangular ligament Left triangular ligament The left triangular ligament is a fold of some considerable size, which connects the posterior part of the upper surface of the left lobe of the liver to the Thoracic diaphragm; its anterior layer is continuous with the left layer of the falciform ligament.... , right triangular ligament Right triangular ligament The right triangular ligament is situated at the right extremity of the bare area, and is a small fold which passes to the Thoracic diaphragm, being formed by the apposition of the upper and lower layers of the coronary ligament....	liver Liver The liver is a vital organ present in vertebrates and some other animals; it has a wide range of functions, a few of which are detoxification, protein synthesis, and production of biochemicals necessary for digestion....		- \|	* umbilical folds Umbilical folds In the urinary bladder, anteriorly there are the following folds:* one median umbilical fold: on the median umbilical ligament * two medial umbilical folds on the occluded umbilical artery...	urinary bladder Urinary bladder In anatomy, the urinary bladder is a solid, muscle, and distensible organ that sits on the pelvic floor in mammals. It is the organ that collects urine excreted by the kidneys prior to disposal by urination....		- \|	* ileocecal fold Ileocecal fold The inferior ileocecal fossa is situated behind the angle of junction of the ileum and cecum. It is formed by the ileocecal fold of peritoneum , the upper border of which is fixed to the ileum, opposite its mesenteric attachment, while the lower border, passing over the ileocecal junction, joins the mesenteriole of the vermiform process, and...	ileum Ileum The ileum is the final section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms posterior intestine or distal intestine may be used instead of ileum....	cecum Cecum The cecum or caecum is a pouch connected to the ascending colon of the large intestine and the ileum. It is separated from the ileum by the ileocecal valve or Bauhin's valve, and is considered to be the beginning of the large intestine....	- \|	* broad ligament of the uterus Broad ligament of the uterus The broad ligament of the uterus is the wide fold of peritoneum that connects the sides of the uterus to the walls and floor of the pelvis....	uterus Uterus The uterus is a major female hormone-responsive reproductive sex organ of most mammals, including humans. It is within the uterus that the fetus develops during gestation....	pelvic wall	mesovarium Mesovarium The mesovarium is the portion of the broad ligament of the uterus that covers the ovary.At first the mesonephros and genital ridge are suspended by a common mesentery, but as the embryo grows the genital ridge gradually becomes pinched off from the mesonephros, with which it is at first continuous, though it still remains connected to the r... , mesosalpinx Mesosalpinx The mesosalpinx is part of the lining of the abdominal cavity in higher vertebrates, specifically the portion of the broad ligament that stretches from the uterine tube to the level of the ovary.... , mesometrium Mesometrium The mesometrium is the mesentery of the uterus. It constitutes the majority of the broad ligament of the uterus, excluding only the portions adjacent to the uterine tube and ovary.... \|- \|	* ovarian ligament Ovarian ligament The ovarian ligament is a fibrous ligament that connects the ovary to the lateral surface of the uterus.This ligament should not be confused with the suspensory ligament of the ovary, which extends from the ovary in the other direction....	uterus Uterus The uterus is a major female hormone-responsive reproductive sex organ of most mammals, including humans. It is within the uterus that the fetus develops during gestation....	inguinal canal Inguinal canal The inguinal canal is a passage in the anterior abdominal wall which in men conveys the spermatic cord and in women the Round ligament of uterus....	- \|	* suspensory ligament of the ovary Suspensory ligament of the ovary The suspensory ligament of the ovary, also infundibulopelvic ligament , is a fold of peritoneum that extends out from the ovary to the wall of the pelvis....	ovary Ovary The ovary is an ovum-producing reproductive organ, often found in pairs as part of the vertebrate female reproductive system. Ovaries in females are homology to testicle in males, in that they are both gonads and endocrine glands....	pelvic wall	ovarian artery Ovarian artery In human anatomy, the ovarian artery is a blood vessel that supplies oxygenated blood to the ovary. It arises from the abdominal aortic artery below the renal artery, and does not pass out of the abdominal cavity....

In addition, in the pelvic cavity

Pelvic cavity

The pelvic cavity is a body cavity that is bounded by the bones of the pelvis and which primarily contains reproductive organs, the urinary bladder, and the rectum....
there are several structures that are usually named not for the peritoneum, but for the areas defined by the peritoneal folds:

Name	Location	Genders possessing structure >- \| Rectovesical pouch	between rectum Rectum The rectum is the final straight portion of the large intestine in some mammals, and the Gastrointestinal tract in others, terminating in the anus.... and urinary bladder Urinary bladder In anatomy, the urinary bladder is a solid, muscle, and distensible organ that sits on the pelvic floor in mammals. It is the organ that collects urine excreted by the kidneys prior to disposal by urination....	- \| Rectouterine pouch	between rectum Rectum The rectum is the final straight portion of the large intestine in some mammals, and the Gastrointestinal tract in others, terminating in the anus.... and uterus Uterus The uterus is a major female hormone-responsive reproductive sex organ of most mammals, including humans. It is within the uterus that the fetus develops during gestation....	- \| Vesicouterine pouch	between urinary bladder Urinary bladder In anatomy, the urinary bladder is a solid, muscle, and distensible organ that sits on the pelvic floor in mammals. It is the organ that collects urine excreted by the kidneys prior to disposal by urination.... and uterus Uterus The uterus is a major female hormone-responsive reproductive sex organ of most mammals, including humans. It is within the uterus that the fetus develops during gestation....	- \| Pararectal fossa Pararectal fossa In the male, the peritoneum encircles the sigmoid colon, from which it is reflected to the posterior wall of the pelvis as a fold, the sigmoid mesocolon....	surrounding rectum Rectum The rectum is the final straight portion of the large intestine in some mammals, and the Gastrointestinal tract in others, terminating in the anus....	- \| Paravesical fossa Paravesical fossa The peritoneum of the anterior pelvic wall covers the superior surface of the Urinary bladder, and on either side of this viscus forms a depression, termed the paravesical fossa, which is limited laterally by the fold of peritoneum covering the ductus deferens....	surrounding urinary bladder Urinary bladder In anatomy, the urinary bladder is a solid, muscle, and distensible organ that sits on the pelvic floor in mammals. It is the organ that collects urine excreted by the kidneys prior to disposal by urination....	male and female

Development

The peritoneum develops ultimately from the mesoderm

Mesoderm

One of the three germ layers found in the embryos of animals more complex than cnidarians, making them triploblastic. Mesoderm forms in the embryo during gastrulation when some of the cells migrating inward to form the endoderm, produce an additional layer that lies between the endoderm and the ectoderm....
of the trilaminar embryo

Trilaminar embryo

A trilaminar embryo is an early stage in the development of triploblastic organisms, which include humans and many other animals.It is an embryo which exists as three different germ layers - the ectoderm, the mesoderm and the endoderm....
. As the mesoderm differentiates, one region known as the lateral plate mesoderm

Lateral plate mesoderm

Lateral plate mesoderm is a type of mesoderm that is found at the periphery of the embryo....
splits to form two layers separated by an intraembryonic coelom

Intraembryonic coelom

The intraembryonic coelom is a a portion of the conceptus forming in the mesoderm. During the second week of development, the lateral mesoderm splits into a dorsal somatic mesoderm and a ventral splanchnic mesoderm ....
. These two layers develop later into the visceral and parietal layers found in all serous cavities, including the peritoneum.

As an embryo

Embryo

An embryo is a multicellular organism ploidy eukaryote in its earliest stage of development, from the time of first cell division until birth, Egg , or germination....
develops, the various abdominal organs grow into the abdominal cavity from structures in the abdominal wall. In this process they become enveloped in a layer of peritoneum. The growing organs "take their blood vessels with them" from the abdominal wall, and these blood vessels become covered by peritoneum, forming a mesentery.

Clinical aspects

Pathology

Pneumoperitoneum
Pneumoperitoneum

Pneumoperitoneum is air or gas in the abdominal cavity. It is often seen on X-ray, but small amounts are often missed, and CT is nowadays regarded as a criterion standard in the assessment of a pneumoperitoneum....
is the presence of gas within the peritoneal cavity, as may occur when a perforation forms in the stomach or intestines. This is a serious condition.
Peritonitis
Peritonitis

Peritonitis is defined as inflammation of the peritoneum . It may be localised or generalised, generally has an acute course, and may depend on either infection or on a non-infectious process....
is an inflammation
Inflammation

Inflammation is the complex biological response of Blood vessel tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. It is a protective attempt by the organism to remove the injurious stimuli as well as initiate the healing process for the tissue....
of the peritoneal lining or cavity, which may occur with either a perforation or by spread of infection through the wall of one of the abdominal organs. This too is a serious condition, and often requires emergency surgery.
Ascites
Ascites

In medicine , ascites is an accumulation of fluid in the peritoneal cavity. Although most commonly due to cirrhosis and severe liver disease, its presence can portend other significant medical problems....
is an accumulation of excess fluid within the peritoneal cavity.
Pagalperitoneum is a south asian genetic mutation where patients lack the inner fold of the peritoneum. Incidence is rare but fatal.

Peritoneal dialysis
Peritoneal dialysis

Introduction Current treatment options for patients with severe chronic kidney failure are dialysis and kidney transplantation. Dialysis is a treatment that removes substances such as water, salts, and waste products , which build up in patients with failing kidneys....

In one form of dialysis

Dialysis

In medicine, dialysis is primarily used to provide an artificial replacement for lost kidney function due to renal failure. Dialysis may be used for very sick patients who have suddenly but temporarily, lost their kidney function or for quite stable patients who have permanently lost their kidney function ....
, the peritoneal dialysis
Peritoneal dialysis

Introduction Current treatment options for patients with severe chronic kidney failure are dialysis and kidney transplantation. Dialysis is a treatment that removes substances such as water, salts, and waste products , which build up in patients with failing kidneys....
, a glucose solution is run through a tube into the peritoneal cavity. The fluid is left there for a prescribed amount of time to absorb waste products, and then removed through the tube. The reason for this effect is the high number of arteries and veins in the peritoneal cavity. Through the mechanism of diffusion

Diffusion

Molecular diffusion, often called simply diffusion, is a net transport of molecules from a region of higher concentration to one of lower concentration by random molecular motion....
, waste products are removed from the blood.

Classification of abdominal structures

The structures in the abdomen are classified as intraperitoneal, retroperitoneal or infraperitoneal depending on whether they are covered with visceral peritoneum and have a mesentery or not.

Intraperitoneal	Retroperitoneal	Infraperitoneal / Subperitoneal >- \| Stomach Stomach In most mammals, the stomach is a hollow muscular organ of the gastrointestinal tract involved in the second phase of digestion, following mastication.... , First part of the duodenum [5 cm], jejunum Jejunum The jejunum is the middle section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms middle intestine or mid-gut may be used instead of jejunum.... , ileum Ileum The ileum is the final section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms posterior intestine or distal intestine may be used instead of ileum.... , Cecum Cecum The cecum or caecum is a pouch connected to the ascending colon of the large intestine and the ileum. It is separated from the ileum by the ileocecal valve or Bauhin's valve, and is considered to be the beginning of the large intestine.... , appendix Vermiform appendix In human anatomy, the appendix is a blind ended tube connected to the cecum , from which it develops embryologically. The cecum is a pouch-like structure of the Colon .... , transverse colon Transverse colon The transverse colon the longest and most movable part of the Colon , passes with a downward convexity from the right hypochondrium region across the abdomen, opposite the confines of the epigastric and umbilical zones, into the left hypochondrium region, where it curves sharply on itself beneath the lower end of the spleen, forming the splen... , sigmoid colon Sigmoid colon The sigmoid colon forms a loop which averages about 40 cm. in length, and normally lies within the pelvis, but on account of its freedom of movement it is liable to be displaced into the abdominal cavity.... , Rectum Rectum The rectum is the final straight portion of the large intestine in some mammals, and the Gastrointestinal tract in others, terminating in the anus.... , upper 1/3	The rest of the duodenum Duodenum The duodenum is the first section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms anterior intestine or proximal intestine may be used instead of duodenum.... , ascending colon Ascending colon The ascending colon is smaller in caliber than the cecum, with which it is continuous.It passes upward, from its commencement at the cecum, opposite the colic valve, to the under surface of the right lobe of the liver, on the right of the gall-bladderyeo, where it is lodged in a shallow depression, the colic impression; here it bends abrupt... , descending colon Descending colon The descending colon of humans passes downward through the left hypochondrium and lumbar regions, along the lateral border of the left kidney.... , Rectum Rectum The rectum is the final straight portion of the large intestine in some mammals, and the Gastrointestinal tract in others, terminating in the anus.... , middle 1/3	Rectum Rectum The rectum is the final straight portion of the large intestine in some mammals, and the Gastrointestinal tract in others, terminating in the anus.... , lower 1/3 \|- \| Liver Liver The liver is a vital organ present in vertebrates and some other animals; it has a wide range of functions, a few of which are detoxification, protein synthesis, and production of biochemicals necessary for digestion.... , Spleen Spleen The spleen is an organ found in all vertebrate animals. In humans, the spleen is located in the abdomen of the body, where it functions in the destruction of redundant red blood cells, and holds a reservoir of blood....	Pancreas Pancreas The pancreas is a gland Organ in the digestive system and endocrine system of vertebrates. It is both an endocrine gland , as well as an exocrine gland, secreting pancreatic juice containing Digestion enzymes that pass to the small intestine....	- \|	Kidney Kidney The kidneys are Organ that have numerous biological roles. Their primary role is to maintain the homeostasis balance of bodily fluids by filtering and secreting Metabolomics#Metabolitess and minerals from the blood and excreting them, along with water , as urine.... s, suprarenal glands, ureter Ureter In human anatomy, the ureters are muscular ducts that propel urine from the kidneys to the urinary bladder. In the adult, the ureters are usually long.... s, renal vessels Renal artery The renal arteries normally arise off the side of the abdominal aorta, immediately below the superior mesenteric artery, and supply the kidneys with blood....	Urinary bladder Urinary bladder In anatomy, the urinary bladder is a solid, muscle, and distensible organ that sits on the pelvic floor in mammals. It is the organ that collects urine excreted by the kidneys prior to disposal by urination.... , ureter Ureter In human anatomy, the ureters are muscular ducts that propel urine from the kidneys to the urinary bladder. In the adult, the ureters are usually long.... s(end) \|- \| In women: Uterus Uterus The uterus is a major female hormone-responsive reproductive sex organ of most mammals, including humans. It is within the uterus that the fetus develops during gestation.... , Fallopian tube Fallopian tube The Fallopian tubes, named after Gabriel Fallopius , also known as oviducts, uterine tubes, and salpinges are two very fine tubes lined with cilia epithelia, leading from the ovaries of female mammals into the uterus.... s, ovaries Ovary The ovary is an ovum-producing reproductive organ, often found in pairs as part of the vertebrate female reproductive system. Ovaries in females are homology to testicle in males, in that they are both gonads and endocrine glands....	Gonadal blood vessels Gonadal artery The term gonadal artery is a generic term for a paired artery, with one arising from the abdominal aorta for each gonad. Specifically, it can refer to:...	- \|	Inferior vena cava Inferior vena cava The inferior vena cava is the large vein that carries de-oxygenated blood from the lower half of the body into the right atrium of the heart.... , Aorta Aorta The aorta is the largest artery in the human body, originating from the left ventricle of the heart and bringing oxygenated blood to all parts of the body in the systemic circulation....

Structures that are intraperitoneal are generally mobile, while those that are retroperitoneal are relatively fixed in their location.

Some structures, such as the kidneys, are "primarily retroperitoneal", while others such as the majority of the duodenum, are "secondarily retroperitoneal", meaning that structure developed intraperitoneally but lost its mesentery

Mesentery

Etymology

Peritoneum is derived from Greek. Peri- means around, while -ton- refers to stretching. Thus, peritoneuum means stretched around or stretched over.

Peritoneum

Structure

Layers

Subdivisions

Development

Clinical aspects

Pathology

Classification of abdominal structures

Etymology

Additional images

External links