[Music] firstly we'll revisit some basic anatomy starting with the position and surfaces of the liver the liver is found underneath the right side of the diaphragm in the right upper quadrant of the abdomen its anterior superior surface is in contact with the underside of the diaphragm whilst its posterior inferior surface is in contact with the underlying viscera never has a number of ligaments which attach it to surrounding structures and for which she may have heard many different names the fast foam ligament attaches the liver to the anterior abdominal wall ligamentum teres also known as the round ligament of the liver is a remnant of the umbilical vein that exists in the free edge of the falciform ligament the anterior folds of the right and left coronary ligaments can also be seen here these form parts of the peritoneal reflexions to hold the liver to the inferior surface of the diaphragm on the posterior side of the liver the posterior fold the left and right coronary ligaments can be seen the anterior and posterior folds of the coronary ligaments converge on the right and left side of the liver to form the right and left triangular ligaments within the margin of these ligaments is an area not covered by peritoneum which is in direct contact with the inferior diaphragm this is known as the bear area also in posterior view the ligamentum teres can be seen again along with the ligamentum venosum this is often attached to the left hepatic vein and is a remnant of the doctors venosus of fetal circulation it forms a fissure between the caudate lobe and the rest of the left lobe and can sometimes be continuous with the ligamentum teres from an anterior position reflecting the liver backed view the visible surface reveals a broad ligament running between the liver and the stomach and the first part of the duodenum for the purpose of this video a small hole has been drawn here to demonstrate the major vessels of the liver that run within this ligament the ligament has two parts the hepatic gastric ligament and the hepato duodenal ligament so named due to where they attach together these two ligaments are known as the lesser omentum looking at liver lobes the liver has both a large left and large right lobe as well as two smaller lobes that can be seen posteriorly the caudate lobe can be seen superiorly and the quadrate inferiorly so depending on the anatomy or diagram being used both of these lobes could subjectively appear square I simply remember which is which by thinking C comes before or above Q in the alphabet and hence caudate above quadrate aside from anatomical lobes the liver is in turn it divides it into eight functional segments each of which is supplied by its own portal triad these segments are really important in the surgical perspective as it allows specialists to clearly locate and communicate the location of a lesion within the liver segment one is found posteriorly and corresponds entirely with the caudate lobe after that each segment is a number starting at the left in a clockwise fashion segment four can further be divided into 4 a and 4 B it is often thought that the falciform ligament divides the liver into its respective left and right lobes but this is false the left lobe of the liver extends laterally to this ligament to an invisible structure known as the can't align line this line demarcates were the middle of the three main hepatic veins run before emptying into the inferior vena cava an easy way to remember the segments of the liver is by making a fist with your right hand and tucking the thumb in the tucked away thumb corresponds to segment one of the caudate which can't be seen anteriorly then similarly too before you move round in a clockwise fashion next we'll revisit the blood supply of the liver in this diagram the segments have been separated from each other to make it easier to visualize this is also how the liver is depicted in operation notes for patients undergoing liver resection firstly we will look at the liver in flow the liver has a dual blood supply one source of blood is through the portal vein which is formed from the joining of other major veins within the abdomen the second source of blood supply is via the hepatic artery this arises from a branch of the celiac trunk the common hepatic artery arises directly from the celiac trunk being one of its three main branches after giving off the bastard duodenal artery it becomes the proper hepatic artery which feeds into the liver at the porta hepatis the proper hepatic artery then divides into the left and right hepatic artery supplying the left and right lobes in turn after supplying eat liver lobule where the blood from each source combines it is drained into a central hepatic vein these hepatic veins form tributaries of larger patek veins which eventually drain into the three main hepatic veins right middle and left each of these veins drains into the ascending inferior vena cava which is found travelling on the posterior and liver surface [Music] you