Retroperitoneum
Encyclopedia
The retroperitoneal space (retroperitoneum) is the anatomical space in the abdominal cavity
behind (retro) the peritoneum
. It has no specific delineating anatomical structures. Organs are retroperitoneal if they only have peritoneum on their anterior side.
The retroperitoneum can be further subdivided into the following:
are termed "retroperitoneal". Organs that were once suspended within the abdominal cavity by mesentery
but migrated posterior to the peritoneum during the course of embryogenesis
to become retroperitoneal are considered to be secondarily retroperitoneal organs.
A useful mnemonic to aid recollection of the abdominal retroperitoneal viscera is SAD PUCKER:
Another mnemonic going along with SAD PUCKER is 112 212111, this correlating to which ones are Primarily (1) or Secondarily (2) Retroperitoneal.
. It contains the following structures:
and the anterior leaf of the renal fascia
. It contains the following structures:
Abdominal cavity
The abdominal cavity is the body cavity of the human body that holds the bulk of the viscera. It is located below the thoracic cavity, and above the pelvic cavity. Its dome-shaped roof is the thoracic diaphragm , and its oblique floor is the pelvic inlet...
behind (retro) the peritoneum
Peritoneum
The peritoneum is the serous membrane that forms the lining of the abdominal cavity or the coelom — it covers most of the intra-abdominal organs — in amniotes and some invertebrates...
. It has no specific delineating anatomical structures. Organs are retroperitoneal if they only have peritoneum on their anterior side.
The retroperitoneum can be further subdivided into the following:
- Perirenal space
- Anterior pararenal space
- Posterior pararenal space
Retroperitoneal structures
Structures that lie behind the peritoneumPeritoneum
The peritoneum is the serous membrane that forms the lining of the abdominal cavity or the coelom — it covers most of the intra-abdominal organs — in amniotes and some invertebrates...
are termed "retroperitoneal". Organs that were once suspended within the abdominal cavity by 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.-Mesentery :The...
but migrated posterior to the peritoneum during the course of embryogenesis
Embryogenesis
Embryogenesis is the process by which the embryo is formed and develops, until it develops into a fetus.Embryogenesis starts with the fertilization of the ovum by sperm. The fertilized ovum is referred to as a zygote...
to become retroperitoneal are considered to be secondarily retroperitoneal organs.
- Primarily retroperitoneal:
- urinary
- adrenal glandAdrenal glandIn mammals, the adrenal glands are endocrine glands that sit atop the kidneys; in humans, the right suprarenal gland is triangular shaped, while the left suprarenal gland is semilunar shaped...
s - kidneyKidneyThe kidneys, organs with several functions, serve essential regulatory roles in most animals, including vertebrates and some invertebrates. They are essential in the urinary system and also serve homeostatic functions such as the regulation of electrolytes, maintenance of acid–base balance, and...
s - ureterUreterIn human anatomy, the ureters are muscular tubes that propel urine from the kidneys to the urinary bladder. In the adult, the ureters are usually long and ~3-4 mm in diameter....
- bladderUrinary bladderThe urinary bladder is the organ that collects urine excreted by the kidneys before disposal by urination. A hollow muscular, and distensible organ, the bladder sits on the pelvic floor...
- adrenal gland
- circulatory
- aortaAortaThe aorta is the largest artery in the body, originating from the left ventricle of the heart and extending down to the abdomen, where it branches off into two smaller arteries...
- inferior vena cavaInferior vena cavaThe inferior vena cava , also known as the posterior 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
- digestive
- esophagusEsophagusThe esophagus is an organ in vertebrates which consists of a muscular tube through which food passes from the pharynx to the stomach. During swallowing, food passes from the mouth through the pharynx into the esophagus and travels via peristalsis to the stomach...
(part) - rectumRectumThe rectum is the final straight portion of the large intestine in some mammals, and the gut in others, terminating in the anus. The human rectum is about 12 cm long...
(part, lower third is extraperitoneal)
- esophagus
- urinary
- Secondarily retroperitoneal:
- the head, neck, and body of the pancreasPancreasThe pancreas is a gland organ in the digestive and endocrine system of vertebrates. It is both an endocrine gland producing several important hormones, including insulin, glucagon, and somatostatin, as well as a digestive organ, secreting pancreatic juice containing digestive enzymes that assist...
(but not the tailTail of pancreasThe 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 Pancreatic Polypeptide cells, which are responsible for secreting pancreatic polypeptide to coordinate exocrine and...
, which is located in the splenorenal ligamentSplenorenal ligamentThe 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...
) - the duodenumDuodenumThe 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...
, except for the proximal first segment, which is intraperitoneal - ascending and descending portions of the colonColon (anatomy)The colon is the last part of the digestive system in most vertebrates; it extracts water and salt from solid wastes before they are eliminated from the body, and is the site in which flora-aided fermentation of unabsorbed material occurs. Unlike the small intestine, the colon does not play a...
(but not the transverse or sigmoid)
- the head, neck, and body of the pancreas
A useful mnemonic to aid recollection of the abdominal retroperitoneal viscera is SAD PUCKER:
- S = Suprarenal glands (aka the adrenal glands)
- A = Aorta/IVC
- D = Duodenum (second and third segments [some also include the fourth segment] )
- P = Pancreas (tail is intraperitoneal)
- U = Ureters
- C = Colon (only the ascending and descending parts)
- K = Kidneys
- E = Esophagus
- R = Rectum
Another mnemonic going along with SAD PUCKER is 112 212111, this correlating to which ones are Primarily (1) or Secondarily (2) Retroperitoneal.
Perirenal Space
Bounded by the anterior and posterior leafs of the renal fasciaRenal fascia
The renal fascia is a layer of connective tissue encapsulating the kidneys. The deeper layers below the renal fascia are, in order, the perinephric fat , renal capsule, and finally the parenchyma of the renal cortex...
. It contains the following structures:
- Adrenal glandAdrenal glandIn mammals, the adrenal glands are endocrine glands that sit atop the kidneys; in humans, the right suprarenal gland is triangular shaped, while the left suprarenal gland is semilunar shaped...
- KidneyKidneyThe kidneys, organs with several functions, serve essential regulatory roles in most animals, including vertebrates and some invertebrates. They are essential in the urinary system and also serve homeostatic functions such as the regulation of electrolytes, maintenance of acid–base balance, and...
- Renal vessels
Anterior pararenal space
Bounded by the posterior layer of peritoneumPeritoneum
The peritoneum is the serous membrane that forms the lining of the abdominal cavity or the coelom — it covers most of the intra-abdominal organs — in amniotes and some invertebrates...
and the anterior leaf of the renal fascia
Renal fascia
The renal fascia is a layer of connective tissue encapsulating the kidneys. The deeper layers below the renal fascia are, in order, the perinephric fat , renal capsule, and finally the parenchyma of the renal cortex...
. It contains the following structures:
- PancreasPancreasThe pancreas is a gland organ in the digestive and endocrine system of vertebrates. It is both an endocrine gland producing several important hormones, including insulin, glucagon, and somatostatin, as well as a digestive organ, secreting pancreatic juice containing digestive enzymes that assist...
- Ascending and descending colonColon (anatomy)The colon is the last part of the digestive system in most vertebrates; it extracts water and salt from solid wastes before they are eliminated from the body, and is the site in which flora-aided fermentation of unabsorbed material occurs. Unlike the small intestine, the colon does not play a...
- Retroperitoneal duodenumDuodenumThe 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...
Posterior pararenal space
Bounded by the posterior leaf of the renal fascia and the muscles of the posterior abdominal wall. It contains only fat.Role in disease
- Retroperitoneal fibrosisRetroperitoneal fibrosisRetroperitoneal fibrosis or Ormond's disease is a disease featuring the proliferation of fibrous tissue in the retroperitoneum, the compartment of the body containing the kidneys, aorta, renal tract and various other structures. It may present with lower back pain, renal failure, hypertension, deep...
- Retroperitoneal lymph node dissectionRetroperitoneal Lymph Node DissectionRetroperitoneal lymph node dissection, commonly referred to as RPLND, is a procedure to remove abdominal lymph nodes to treat testicular cancer, as well as help establish its exact stage and type. It is usually performed using an incision that extends from the sternum to several inches below the...
- Retroperitoneal hemorrhageRetroperitoneal hemorrhageRetroperitoneal hemorrhage refers to an accumulation of blood found in the retroperitoneal space.It can present with Grey Turner's sign .Causes include:* anticoagulation* a ruptured aortic aneurysm...