The lesser sac, also known as the omental bursa, is a part of the

peritoneal cavity The peritoneal cavity is a potential space between the parietal peritoneum (the peritoneum that surrounds the abdominal wall) and visceral peritoneum (the peritoneum that surrounds the internal organs). The parietal and visceral peritonea are lay ...

that is formed by the

lesser Lesser, from Eliezer (, "Help/Court of my God"), is a surname. Notable people with the surname include: * Adolf Lesser (1851–1926), German physician * Aleksander Lesser (1814–1884), Polish painter and art critic * Anton Lesser (born 1952), Bri ...

and

greater omentum The greater omentum (also the great omentum, omentum majus, gastrocolic omentum, epiploon, or, especially in animals, caul) is a large apron-like fold of visceral peritoneum that hangs down from the stomach. It extends from the greater curvature ...

. Usually found in mammals, it is connected with the

greater sac In human anatomy, the greater sac, also known as the general cavity (of the abdomen) or peritoneum of the peritoneal cavity proper, is the cavity in the abdomen that is inside the peritoneum but outside the lesser sac. It is connected with the ...

via the

omental foramen In human anatomy, the omental foramen (epiploic foramen, foramen of Winslow after the anatomist Jacob B. Winslow, or uncommonly aditus; la, Foramen epiploicum), is the passage of communication, or foramen, between the greater sac (general cavity ...

or ''Foramen of Winslow''. In mammals, it is common for the lesser sac to contain considerable amounts of fat.

Anatomic margins

;Anterior margin: listed from the top-to-bottom margin:

Quadrate lobe In human anatomy, the liver is divided grossly into four parts or lobes: the right lobe, the left lobe, the caudate lobe, and the quadrate lobe. Seen from the front – the diaphragmatic surface - the liver is divided into two lobes: the right ...

of the

liver The liver is a major Organ (anatomy), organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of proteins and biochemicals necessary for ...

lesser omentum The lesser omentum (small omentum or gastrohepatic omentum) is the double layer of peritoneum that extends from the liver to the lesser curvature of the stomach, and to the first part of the duodenum. The lesser omentum is usually divided into th ...

stomach The stomach is a muscular, hollow organ in the gastrointestinal tract of humans and many other animals, including several invertebrates. The stomach has a dilated structure and functions as a vital organ in the digestive system. The stomach i ...

gastrocolic ligament The gastrocolic ligament is a portion of the greater omentum that stretches from the greater curvature of the stomach to the transverse colon. It forms part of the anterior wall of the lesser sac. Dividing the gastrocolic ligament provides access ...

;Lateral margin: listed from the most anterior to the most posterior margin:

Gastrosplenic ligament The gastrosplenic ligament (also known as the ''ligamentum gastrosplenicum'' or gastrolienal ligament) is part of the greater omentum extending between the stomach and the spleen. It contains several blood vessels. Structure The gastrosplenic li ...

spleen The spleen is an organ found in almost all vertebrates. Similar in structure to a large lymph node, it acts primarily as a blood filter. The word spleen comes .

phrenicosplenic ligament The greater omentum (also the great omentum, omentum majus, gastrocolic omentum, epiploon, or, especially in animals, caul) is a large apron-like fold of visceral peritoneum that hangs down from the stomach. It extends from the greater curvature o ...

;Posterior margin: Left

kidney The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; blood ...

and

adrenal gland The adrenal glands (also known as suprarenal glands) are endocrine glands that produce a variety of hormones including adrenaline and the steroids aldosterone and cortisol. They are found above the kidneys. Each gland has an outer cortex which ...

pancreas The pancreas is an organ of the digestive system and endocrine system of vertebrates. In humans, it is located in the abdomen behind the stomach and functions as a gland. The pancreas is a mixed or heterocrine gland, i.e. it has both an end ...

;Inferior margin:

Greater omentum The greater omentum (also the great omentum, omentum majus, gastrocolic omentum, epiploon, or, especially in animals, caul) is a large apron-like fold of visceral peritoneum that hangs down from the stomach. It extends from the greater curvature ...

;Superior margin:

Liver The liver is a major Organ (anatomy), organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of proteins and biochemicals necessary for ...

If any of the marginal structures rupture their contents could leak into the lesser sac. If the stomach were to rupture on its anterior side though the leak would collect in the

. The lesser sac is formed during

embryogenesis An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male sperm ...

from an infolding of the greater omentum. The open end of the infolding, known as the

is usually close to the stomach.

Additional images

File:Gray989.png, Schematic figure of the bursa omentalis, etc. Human embryo of eight weeks. File:Gray990.png, Diagrams to illustrate the development of the greater omentum and transverse mesocolon. File:Slide7ddd.JPG, Omental bursa

References

External links

* * – "Abdominal Cavity: The Lesser Peritoneal Sac" * {{DEFAULTSORT:Lesser Sac General surgery Abdomen es:Mesenterio#Transcavidad de los epiplones

Anatomic margins

Additional images

See also

References

External links