What is the Difference Between Peritoneal and Retroperitoneal

The key difference between peritoneal and retroperitoneal is that peritoneal is the anatomical space between the parietal and visceral peritoneum, while retroperitoneal is an anatomical space located behind the abdominal or peritoneal cavity.

There are different cavities or spaces located within the human body, such as the cranial cavity, thoracic cavity, spinal cavity, abdominal or peritoneal cavity, retroperitoneal space, and pelvic cavity. They are extremely important as major organs are located within these cavities or spaces. Peritoneal and retroperitoneal are two spaces located in the human body. Both spaces hold different important organs. Peritoneal holds the stomach, spleen, liver, first and fourth parts of the duodenum, jejunum, ileum, transverse, and sigmoid colon, while retroperitoneal holds ureters, suprarenal glands, and kidneys.

CONTENTS

1. Overview and Key Difference
2. What is Peritoneal 
3. What is Retroperitoneal
4. Similarities – Peritoneal and Retroperitoneal
5. Peritoneal vs. Retroperitoneal in Tabular Form
6. FAQ – Peritoneal and Retroperitoneal
7. Summary – Peritoneal vs. Retroperitoneal

What is Peritoneal?

Peritoneal is also known as peritoneal cavity. It is the potential space between the parietal peritoneum and visceral peritoneum. The parietal peritoneum and visceral peritonea are two different layers of the peritoneum. Peritoneal is one of the spaces derived from the coelomic cavity of the embryo. Peritoneal is the largest cavity or space in the body. It is also the largest fluid-filled cavity in the body. Peritoneal is divided into two compartments: one above the transverse colon (supracolic compartment) and one below the transverse colon (infracolic compartment).

Moreover, the liver, spleen, stomach, and lesser omentum are within the supracolic compartment, whereas the small intestine is surrounded by ascending, transverse, and descending colon and paracolic gutters, are within the infracolic compartment. Furthermore, peritoneal is also clinically significant as ascites is a condition in which fluid collects in the peritoneal cavity.

What is Retroperitoneal?

Retroperitoneal is an anatomical space located behind the abdominal or peritoneal cavity. Normally, abdominal organs that are not suspended by the mesentery, which lies between the abdominal wall and the parietal peritoneum, are said to lie within this space. Several individual spaces make up the retroperitoneal space. These spaces are anterior pararenal space, posterior pararenal space, and perirenal space.

The anterior pararenal space contains the head, neck, and body of the pancreas, ascending and descending colon, and the duodenum. Meanwhile, the perirenal space contains the adrenal gland, kidney, ureters, and renal vessels. The posterior pararenal space contains no major organs, and it is composed primarily of fat, blood vessels, and lymphatics. Furthermore, retroperitoneal is clinically significant as bleeding from a blood vessel or structure, such as the aorta or inferior vena cava, into the retroperitoneal space can lead to a retroperitoneal hemorrhage.

What are the Similarities Between Peritoneal and Retroperitoneal?

• Peritoneal and retroperitoneal are two spaces located in the human body.
• Both spaces are located near each other.
• They hold different major organs.
• Both spaces are clinically significant.

What is the Difference Between Peritoneal and Retroperitoneal?

Peritoneal is the anatomical space between the parietal and visceral peritoneum, while retroperitoneal is an anatomical space located behind the abdominal or peritoneal cavity. This is the key difference between peritoneal and retroperitoneal. Furthermore, the peritoneal is comparatively a larger space, while the retroperitoneal is comparatively a smaller space.

The infographic below presents the differences between peritoneal and retroperitoneal in tabular form for side-by-side comparison.

FAQ: Peritoneal and Retroperitoneal

How do you identify retroperitoneal organs?

The retroperitoneal cavity is the space located behind the intraperitoneal space where the kidneys are located.

What are the 6 retroperitoneal organs?

Kidneys, adrenal glands, pancreas, nerve roots, lymph nodes, abdominal aorta, and inferior vena cava are the major organs held by retroperitoneal space.

Is urinary bladder retroperitoneal?

The urinary bladder is a retroperitoneal organ.

Summary – Peritoneal vs. Retroperitoneal

Peritoneal and retroperitoneal are spaces located very closely. Peritoneal is the anatomical space between the parietal and visceral peritoneum, while retroperitoneal is an anatomical space located behind the abdominal or peritoneal cavity. Peritoneal holds the stomach, spleen, liver, first and fourth parts of the duodenum, jejunum, ileum, transverse, and sigmoid colon, while retroperitoneal holds ureters, suprarenal glands, and kidneys. So, this summarizes the difference between peritoneal and retroperitoneal.

Reference:

1. “The Peritoneal (Abdominal) Cavity.” TeachMeAnatomy.
2. “Retroperitoneal Space.” Science Direct.

Image Courtesy:

1. “Retroperitoneal spaces and fasciae” By Goran Mitreski and Tom Sutherland – Mitreski G, Sutherland T (2017). “Radiological diagnosis of perinephric pathology: pictorial essay 2015” Insights Imaging 8 (1): 155-169. DOI:10.1007/s13244-016-0536-z. PMID 28050791. PMC: 5265200.- (CC BY 4.0) via Commons Wikimedia
2. “2403 The PeritoneumN” By OpenStax College – Anatomy & Physiology, Connexions Web site, Jun 19, 2013. (CC BY 3.0) via Commons Wikimedia