[Biology Class Notes] on Omentum Pdf for Exam

The omentum is an important part of the human digestive system that is located in the lower abdominal section. There are two different layers of fatty tissue that create the omentum. The main function of these tissues is to ensure the covering and support of the intestines and organs that come under that particular area. 

The omentum is divided into two different parts known as the greater and lesser omentum. These are responsible for storing deposits of fats and acting as a connection between the intestines, stomach, and liver. This article explains the function and anatomy of the omentum. 

Omentum Meaning

Also known as the epiploon, omentum majus, or gastrocolic omentum, the greater omentum is a very important part of the organ system. In certain animals, the greater omentum is also known as the caul. This organ is a part of the visceral peritoneum and has a long fold hanging down from the start of the stomach. The greater omentum passes from the greater curvature of the stomach before moving along the small intestine to finally join the transverse colon. The posterior abdominal wall is where the greater omentum goes to. The greater omentum provides a floating-like appearance to the small intestines and it is here that greater omentum got its name ‘epiploon’ from. The word is a Greek substitute for sailing or floating. 

Another term used for describing the lesser omentum is the smaller omentum or the gastrohepatic omentum. This is basically a major part of the peritoneum that can be found having a double layer and it extends from the duodenum and the lesser curvature of the stomach to the liver. 

Omentum Anatomy 

From the left side, the greater omentum has connections with the gastrolienal ligament and it is connected to the duodenum’s beginning on the right side. In certain cases, the greater omentum has a thin shape with an appearance of a cribriform and it also consists of some adipose tissues. The greater omentum consists of the gastrocolic ligament which is connected to the transverse colon. Apart from that, it is also connected to the gastrosplenic ligament which is joined to the spleen. A part of the splenorenal ligament that is connected to the left kidney and the spleen is also sometimes included in the omentum anatomy. There are gastroepiploic vessels that are also responsible for enabling blood supply in the greater omentum.

One of the main differences between greater and lesser omentum is that the latter has a thin shape. It can be in continuous connection with the different peritoneum layers that end up covering the anterosuperior and posteroinferior surfaces of the stomach along with the first section of the duodenum. The double layers in the lesser omentum go directly to the lesser curvature of the stomach along with the duodenum’s upper section. There, they join and create a double fold while ascending towards the porta hepatis where it is attached to the fossa of the ductus venosus. 

There are several ligaments dividing the lesser omentum. In certain cases, the lesser omentum has two ligaments separating it. The hepatogastric ligament is joined up with the lesser curvature of the stomach while the hepatoduodenal ligament joins up with the duodenum. Apart from that, the hepatophrenic ligament is connected with the thoracic diaphragm while the hepatoesophageal ligament is joined with the oesophagus and the hepatocolic ligament is joined with the colon.

Omentum Function 

The greater omentum is majorly responsible for the deposition of fat and it contains large amounts of adipose tissue that varies according to the person. One major function of greater omentum is to make contributions to the immunity of the body. There are macrophage collections in the greater omentum. In addition to that, the greater omentum assists in isolating the wounds and infections inside as it wraps itself around those areas which have been infected. This helps in providing the right amount of protection that the traumatized organs or areas might require. However, fat deposition still remains the major function of the greater omentum. 

Omentum Inflammation and Solutions 

During the healthy stages, the omentum will have a pretty transparent appearance with a lace-like structure. However, when it is unhealthy, the omentum is filled with fat and appears opaque with thick properties. This stage can actually lead to a lot of diseases and health issues including inflammation, unstable levels of blood sugar, unhealthy arteries, etc. The ideal size of the male omentum is about 35 inches and a female omentum is about 32.5 inches. 

Conclusion 

The omentum assumes the role of policeman for the entire abdomen. It can be defined as the doubled-up layer of tissue consisting of fat that supports and covers all the organs and intestines found in the lower abdominal area. The greater omentum is important for storing the different deposits of fat and the lesser omentum supports and holds the intestines and stomach.