Anatomy of the Liver

This video is about the gross anatomy of liver as a discussion topic for dissection. Let's see about the external features of the liver. The liver has 5 surfaces. These are anterior surface, posterior surface, superior surface, inferior surface and the right surface. The inferior border is the only well defined border in the liver. It separates the anterior surface. from the inferior surface and it also separates the right surface from the inferior surface. On the anterior surface it presents a notch which is an interlobar notch for the ligamentum teres hepatis. It also presents another notch namely the cystic notch for the fundus of the gallbladder. The inferior margin is at the level of tip of 9th costal cartilage on the right side and tip of 8th costal cartilage on the left side. On the right side at the level of tip of 9th costal cartilage we have the cystic notch where we have the fundus of the gallbladder. This is why Murphy's point is situated at the tip of right 9th costal cartilage where we have maximum tenderness in case of inflammation of the gallbladder. Let's see a detailed description of each of the five surfaces of the liver. The anterior surface is the largest surface of the liver. It's related to the muscles of the anterior abdominal wall, especially the rectus abdominis covered by the rectus sheath. The falciform ligament is attached to the entire anterior surface and it forms a landmark for anatomical division of the liver into right and left lobes. The shaded area represents the posterior surface of the liver. The posterior surface of the liver presents the following features from the right to the left. In the right extreme of the posterior surface we have the triangular bar area of liver which is the largest area on the liver not covered by the peritoneum. To the left of the bar area we have the groove for inferior vena cava in which is lodged the inferior vena cava. Then we have the caudate lobe and to the left of the caudate lobe we have the fissure for ligamentum venosum which lodges the ligamentum venosum. This shows the ligamentum venosum Lodged in the fissure for ligamentum venosum. Ligamentum venosum is obliterated ductus venosus. In the fetal life, the ductus venosus connects the left branch of portal vein to the inferior vena cava in order to bypass the liver. The shaded area represents the inferior surface of the liver. The inferior surface of the liver presents the following features from right to the left. First we have the fossa of gallbladder which lodges the gallbladder. To the left of the fossa of gallbladder we have the quadrate lobe of the liver. To the left of the quadrate lobe we have the fissure for ligamentum teres hepatis. Ligamentum teres hepatis is obliterated left umbilical vein. The posterior surface is separated from the inferior surface by an imaginary line drawn along the porta hepatis. the posterior and inferior surfaces and it presents the following three structures namely the right and left hepatic ducts, the right and left hepatic arteries and the right and left branches of portal vein. Out of these the hepatic arteries and the portal vein enter the liver at the hilum whereas the hepatic ducts leave the liver at the hilum. Coming to the arrangement of structures in the porta hepatis, the posterior most structure is the portal vein. Anteriorly and to the right we have the hepatic ducts. However, in this image we are able to see only the bile duct. Anteriorly and to the left we have the hepatic arteries. The posterior and inferior surfaces of the liver are called as visceral surface and they are related to the following viscera. The left lobe of the liver is related to the esophagus and the stomach. The quadrate lobe is related to the pylorus and the first part of the duodenum. The force of a gallbladder is related to the second part of duodenum. The right lobe of the liver is related to the hepatic flexure of colon on its inferior surface. The right kidney is present in both the posterior surface and the inferior surface of the right lobe. And the right suprarenal gland is related to the bar area of the liver. The superior surface shows the following features. From right to left, these are the right triangular ligament, the superior layer of coronary ligament, the hepatic wings draining into the IVC, the falciform ligament splitting into two and the left triangular ligament. The right surface is related to the right 7th to 11th ribs. To study the relation of the right surface, we can divide it into upper 1 3rd, middle 1 3rd and the lower 1 3rd. The upper 1 3rd is related from deep to superficial to the following structures, lung, pleura and diaphragm. The middle 1 3rd is related to pleura and diaphragm as the lower border of lung ends at the level of 8th rib in the midaxillary line. The lower 1 third is related only to the diaphragm as the inferior border of pleura ends at the level of 10th rib in the midaxillary line. So the upper 1 third is related to lung pleura and diaphragm, middle 1 third to the pleura and diaphragm specifically the costodiaphragmatic recess of the pleura and the lower 1 third is related to the diaphragm. Now let's see how to hold the liver in anatomical position. So you can see the inferior vena cava. Inferior vena cava is lodged in groove for inferior vena cava situated on the posterior surface of the liver. Now it will be convenient to hold the liver in anatomical position if you insert your finger into the inferior vena cava and then you lift up the liver such that the anterior surface with the falciform ligament is facing in front. So now you can see the anterior surface then the superior surface, the posterior surface is the one with the groove for inferior vena cava and the inferior surface is one with the force of a gallbladder. So this is the ideal way to hold it in anatomical position. Moving on to the anatomical division of liver into lobes. The liver is anatomically divided into a large right lobe and a smaller left lobe. by the attachment of falciform ligament on the anterior surface of the liver. On the posterior surface, the fissure for ligamentum venosum separates the right and left lobes anatomically and on the inferior surface the fissure for ligamentum teres hepatis separates the right and left lobes anatomically. The caudate lobe is present on the posterior surface of right lobe of the liver. The caudate lobe is bounded to the right by the groove for inferior vena cava. and to the left by the fissure for ligamentum venosum. Inferiorly the caudate lobe is bounded by the porta hepatis. It is connected to the right lobe of the liver by the caudate process. Inferiorly and to the left it presents a small rounded elevation called the papillary process. The caudate process forms the roof of the epiploid foramen. The quadrate lobe is situated on the inferior surface of right lobe of the liver. It is rectangular in shape and hence its name quadrate. It is bounded to the right by the fossa for gallbladder, to the left by the fissure for ligamentum teres hepatis, anteriorly by the inferior border and posteriorly by the porta hepatis. The left lobe of the liver is much smaller than the right lobe, it forms only one sixth of the liver. Near the fissure for ligamentum venosum, it presents a rounded elevation called the omental tuberosity. Now let's see the peritoneal relations of the liver. This is an intraperitoneal organ. It develops within the ventral mesogastrium. The part of ventral mesogastrium between the liver and the anterior abdominal wall forms a falciform ligament and the part of ventral mesogastrium between the liver and the gut tube forms the lesser omentum. The falciform ligament is thus a double layer of peritoneum. It is attached to the anterior abdominal wall above the umbilicus and extends to the anterior surface of liver. The posterior free margin of the falciform ligament contains the ligamentum teres hepatis which is the obliterated left umbilical vein. This picture, the tight structure is the ligamentum teres hepatis which is the content of the free posterior margin of the falciform ligament. On reaching the superior surface of the liver, the two layers of falciform ligament separate and go towards the diaphragm. They get reflected back from the diaphragm to continue as the visceral peritoneum of the liver. This reflection forms the superior layer of the coronary ligament, the right triangular ligament and the left triangular ligament. The inferior layer of the coronary ligament is formed by the reflection of the visceral layer back towards the diaphragm to continue as the parietal layer of the peritoneum. This is the falciform ligament, this is the anterior layer of the coronary ligament and this is the left triangular ligament. The bare area of liver is a triangular area not covered by peritoneum. It is present on the right lobe mainly occupying the posterior surface and a part of it also extends into the superior surface. It is bound by the superior and the inferior layers of the coronary ligament. The base is formed by the groove for the inferior vena cava and the apex is directed towards the right and it is formed by the right triangular ligament. The bare area is a site of portocaval anastomosis. The liver is not covered by peritoneum along the attachment of lesser omentum. The lesser omentum is attached around the margins of porta hepatis and into the floor of fissure for ligamentum venosum. Thus, the porta hepatis and the floor of fissure for ligamentum venosum are not covered by peritoneum. Summing up the areas of liver which are not covered by peritoneum on the posterior surface from right to the left we have the bare area of the liver, the groove for inferior vena cava and the fissure for ligamentum venosum. The porta hepatis which separates the posterior and the inferior surfaces is also not covered by the peritoneum. On the inferior surface the force of the gallbladder and the fissure for ligamentum teres hepatis are not covered by the peritoneum. The liver is supplied by the hepatic arteries and the portal vein. The venous drainage of the liver is by the hepatic veins which drain into the inferior vena cava. Liver being a Fogart derivative, it is supplied by the celiac trunk. The celiac trunk gives off the splenic artery, left gastric artery and the common hepatic artery. The common hepatic artery is the one which is going to supply the liver. The common hepatic artery Once it gives off the gastrodurinal artery, we are going to name it as the proper hepatic artery. The proper hepatic artery terminates by dividing into the right and left hepatic arteries. The right and left hepatic arteries enter the liver at the porta hepatis. The cystic artery is a branch from the right hepatic artery. Only 20% of blood supply of liver comes from the hepatic arteries and the remaining 80% is from the portal vein. In this image, you can see the hepatic veins opening into the inferior vena cava. Thus, it is very clear that the hepatic veins drain into the inferior vena cava and you cannot look for them at the porta hepatis. The porta hepatis does not contain the hepatic veins. Thank you for watching this video. Hope it will help you in answering the viva discussion.

This video is about the gross anatomy of liver as a discussion topic for dissection. Let's see about the external features of the liver. The liver has 5 surfaces.

These are anterior surface, posterior surface, superior surface, inferior surface and the right surface. The inferior border is the only well defined border in the liver. It separates the anterior surface. from the inferior surface and it also separates the right surface from the inferior surface. On the anterior surface it presents a notch which is an interlobar notch for the ligamentum teres hepatis.

It also presents another notch namely the cystic notch for the fundus of the gallbladder. The inferior margin is at the level of tip of 9th costal cartilage on the right side and tip of 8th costal cartilage on the left side. On the right side at the level of tip of 9th costal cartilage we have the cystic notch where we have the fundus of the gallbladder.

This is why Murphy's point is situated at the tip of right 9th costal cartilage where we have maximum tenderness in case of inflammation of the gallbladder. Let's see a detailed description of each of the five surfaces of the liver. The anterior surface is the largest surface of the liver. It's related to the muscles of the anterior abdominal wall, especially the rectus abdominis covered by the rectus sheath. The falciform ligament is attached to the entire anterior surface and it forms a landmark for anatomical division of the liver into right and left lobes.

The shaded area represents the posterior surface of the liver. The posterior surface of the liver presents the following features from the right to the left. In the right extreme of the posterior surface we have the triangular bar area of liver which is the largest area on the liver not covered by the peritoneum.

To the left of the bar area we have the groove for inferior vena cava in which is lodged the inferior vena cava. Then we have the caudate lobe and to the left of the caudate lobe we have the fissure for ligamentum venosum which lodges the ligamentum venosum. This shows the ligamentum venosum Lodged in the fissure for ligamentum venosum.

Ligamentum venosum is obliterated ductus venosus. In the fetal life, the ductus venosus connects the left branch of portal vein to the inferior vena cava in order to bypass the liver. The shaded area represents the inferior surface of the liver. The inferior surface of the liver presents the following features from right to the left. First we have the fossa of gallbladder which lodges the gallbladder.

To the left of the fossa of gallbladder we have the quadrate lobe of the liver. To the left of the quadrate lobe we have the fissure for ligamentum teres hepatis. Ligamentum teres hepatis is obliterated left umbilical vein. The posterior surface is separated from the inferior surface by an imaginary line drawn along the porta hepatis. the posterior and inferior surfaces and it presents the following three structures namely the right and left hepatic ducts, the right and left hepatic arteries and the right and left branches of portal vein.

Out of these the hepatic arteries and the portal vein enter the liver at the hilum whereas the hepatic ducts leave the liver at the hilum. Coming to the arrangement of structures in the porta hepatis, the posterior most structure is the portal vein. Anteriorly and to the right we have the hepatic ducts.

However, in this image we are able to see only the bile duct. Anteriorly and to the left we have the hepatic arteries. The posterior and inferior surfaces of the liver are called as visceral surface and they are related to the following viscera.

The left lobe of the liver is related to the esophagus and the stomach. The quadrate lobe is related to the pylorus and the first part of the duodenum. The force of a gallbladder is related to the second part of duodenum.

The right lobe of the liver is related to the hepatic flexure of colon on its inferior surface. The right kidney is present in both the posterior surface and the inferior surface of the right lobe. And the right suprarenal gland is related to the bar area of the liver. The superior surface shows the following features.

From right to left, these are the right triangular ligament, the superior layer of coronary ligament, the hepatic wings draining into the IVC, the falciform ligament splitting into two and the left triangular ligament. The right surface is related to the right 7th to 11th ribs. To study the relation of the right surface, we can divide it into upper 1 3rd, middle 1 3rd and the lower 1 3rd. The upper 1 3rd is related from deep to superficial to the following structures, lung, pleura and diaphragm.

The middle 1 3rd is related to pleura and diaphragm as the lower border of lung ends at the level of 8th rib in the midaxillary line. The lower 1 third is related only to the diaphragm as the inferior border of pleura ends at the level of 10th rib in the midaxillary line. So the upper 1 third is related to lung pleura and diaphragm, middle 1 third to the pleura and diaphragm specifically the costodiaphragmatic recess of the pleura and the lower 1 third is related to the diaphragm. Now let's see how to hold the liver in anatomical position. So you can see the inferior vena cava.

Inferior vena cava is lodged in groove for inferior vena cava situated on the posterior surface of the liver. Now it will be convenient to hold the liver in anatomical position if you insert your finger into the inferior vena cava and then you lift up the liver such that the anterior surface with the falciform ligament is facing in front. So now you can see the anterior surface then the superior surface, the posterior surface is the one with the groove for inferior vena cava and the inferior surface is one with the force of a gallbladder. So this is the ideal way to hold it in anatomical position.

Moving on to the anatomical division of liver into lobes. The liver is anatomically divided into a large right lobe and a smaller left lobe. by the attachment of falciform ligament on the anterior surface of the liver.

On the posterior surface, the fissure for ligamentum venosum separates the right and left lobes anatomically and on the inferior surface the fissure for ligamentum teres hepatis separates the right and left lobes anatomically. The caudate lobe is present on the posterior surface of right lobe of the liver. The caudate lobe is bounded to the right by the groove for inferior vena cava. and to the left by the fissure for ligamentum venosum.

Inferiorly the caudate lobe is bounded by the porta hepatis. It is connected to the right lobe of the liver by the caudate process. Inferiorly and to the left it presents a small rounded elevation called the papillary process.

The caudate process forms the roof of the epiploid foramen. The quadrate lobe is situated on the inferior surface of right lobe of the liver. It is rectangular in shape and hence its name quadrate. It is bounded to the right by the fossa for gallbladder, to the left by the fissure for ligamentum teres hepatis, anteriorly by the inferior border and posteriorly by the porta hepatis. The left lobe of the liver is much smaller than the right lobe, it forms only one sixth of the liver.

Near the fissure for ligamentum venosum, it presents a rounded elevation called the omental tuberosity. Now let's see the peritoneal relations of the liver. This is an intraperitoneal organ.

It develops within the ventral mesogastrium. The part of ventral mesogastrium between the liver and the anterior abdominal wall forms a falciform ligament and the part of ventral mesogastrium between the liver and the gut tube forms the lesser omentum. The falciform ligament is thus a double layer of peritoneum. It is attached to the anterior abdominal wall above the umbilicus and extends to the anterior surface of liver.

The posterior free margin of the falciform ligament contains the ligamentum teres hepatis which is the obliterated left umbilical vein. This picture, the tight structure is the ligamentum teres hepatis which is the content of the free posterior margin of the falciform ligament. On reaching the superior surface of the liver, the two layers of falciform ligament separate and go towards the diaphragm.

They get reflected back from the diaphragm to continue as the visceral peritoneum of the liver. This reflection forms the superior layer of the coronary ligament, the right triangular ligament and the left triangular ligament. The inferior layer of the coronary ligament is formed by the reflection of the visceral layer back towards the diaphragm to continue as the parietal layer of the peritoneum.

This is the falciform ligament, this is the anterior layer of the coronary ligament and this is the left triangular ligament. The bare area of liver is a triangular area not covered by peritoneum. It is present on the right lobe mainly occupying the posterior surface and a part of it also extends into the superior surface. It is bound by the superior and the inferior layers of the coronary ligament. The base is formed by the groove for the inferior vena cava and the apex is directed towards the right and it is formed by the right triangular ligament.

The bare area is a site of portocaval anastomosis. The liver is not covered by peritoneum along the attachment of lesser omentum. The lesser omentum is attached around the margins of porta hepatis and into the floor of fissure for ligamentum venosum.

Thus, the porta hepatis and the floor of fissure for ligamentum venosum are not covered by peritoneum. Summing up the areas of liver which are not covered by peritoneum on the posterior surface from right to the left we have the bare area of the liver, the groove for inferior vena cava and the fissure for ligamentum venosum. The porta hepatis which separates the posterior and the inferior surfaces is also not covered by the peritoneum. On the inferior surface the force of the gallbladder and the fissure for ligamentum teres hepatis are not covered by the peritoneum. The liver is supplied by the hepatic arteries and the portal vein.

The venous drainage of the liver is by the hepatic veins which drain into the inferior vena cava. Liver being a Fogart derivative, it is supplied by the celiac trunk. The celiac trunk gives off the splenic artery, left gastric artery and the common hepatic artery. The common hepatic artery is the one which is going to supply the liver.

The common hepatic artery Once it gives off the gastrodurinal artery, we are going to name it as the proper hepatic artery. The proper hepatic artery terminates by dividing into the right and left hepatic arteries. The right and left hepatic arteries enter the liver at the porta hepatis.

The cystic artery is a branch from the right hepatic artery. Only 20% of blood supply of liver comes from the hepatic arteries and the remaining 80% is from the portal vein. In this image, you can see the hepatic veins opening into the inferior vena cava.

Thus, it is very clear that the hepatic veins drain into the inferior vena cava and you cannot look for them at the porta hepatis. The porta hepatis does not contain the hepatic veins. Thank you for watching this video.

Hope it will help you in answering the viva discussion.

Transcript for:Anatomy of the Liver

Transcript for:
Anatomy of the Liver