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distribution, or storage. At the same time, the liver receives blood from the corporeal circulation, initially via the umbilical vein, and after birth via the hepatic artery. The blood and its contents are processed by the interfacing hepatocytes and the blood is subsequently pooled and collected by the hepatic veins which drain into the vena cava.

The liver also fulfills a role in detoxification of products absorbed into the gut. Some of the detoxified by-products are returned to the gut via the biliary system. Anatomically, it makes sense that the bile ducts are closely related to the inflow system. Portal venules, small arterial branches, and bile ducts form the portal triad. The combination of these three systems and the smallest microscopic functional units of the liver can be followed macroscopically from the outside of the liver. Although the adult liver is one solid organ, the branching tree-like structure, with the branches consisting of ever smaller bile ducts, portal veins, and hepatic arteries, allows the liver to be divided in functional units and facilitates surgical dissection (Fig. 11-1). Outflow of

Figure 11-1 Early detailed anatomic drawings of intrahepatic anatomy(clear portion indicates theportal vein, shaded portion indicates the biliary tree, blackportions indicate hepatic artery).

(Source: Used with permission from Sutherland F, Claude Couinaud HJ. A passion for the liver. Arch Surg 137:1305-1310, 2002.)

Figure 11-1 Early detailed anatomic drawings of intrahepatic anatomy(clear portion indicates theportal vein, shaded portion indicates the biliary tree, blackportions indicate hepatic artery).

(Source: Used with permission from Sutherland F, Claude Couinaud HJ. A passion for the liver. Arch Surg 137:1305-1310, 2002.)

blood from the liver into circulation is arranged in a similar fashion, collecting smaller veins into larger hepatic veins, ultimately reaching a left, middle, or right hepatic vein. Applying the known branching structure of the liver, Dr. Couinaud described segmental units and divisional systems that revolutionized hepatobiliary surgery and is used to date to facilitate resection planes in the liver (Fig. 11-2).2

Of note, human biliary anatomy, unlike animals, has one additional feature —a gallbladder. Bile is used in the gut to facilitate in the uptake of fat, by breaking fat up like detergent into micelles. Connected to the common bile duct via the cystic duct, bile is collected in the gallbladder to store until it is needed. An intricate hormonal signaling system is in place to signal the gallbladder to contract in order to eject bile into the duodenum as needed at the time of gastric distention with food.

The external anatomy of the liver allows for identification of some landmarks. The umbilical vein becomes obsolete after birth, but remains as the lig-amentum Teres, which can be found in the falciform ligament. This ligament,

Claude Couinaud

Figure 11-2 Couinaud's early diagram of the segmental anatomy of the liver. Segments are numbered clockwise with Roman numerals. Segment I is the caudate lobe, not seen underneath.

(Source: Used with permission from Sutherland F, Claude Couinaud HJ. A passion for the liver. Arch Surg 137:1305-1310, 2002.)

Figure 11-2 Couinaud's early diagram of the segmental anatomy of the liver. Segments are numbered clockwise with Roman numerals. Segment I is the caudate lobe, not seen underneath.

(Source: Used with permission from Sutherland F, Claude Couinaud HJ. A passion for the liver. Arch Surg 137:1305-1310, 2002.)

historically has been used to divide the liver into a left and a right lobe; however, using known segmental anatomy, an imaginary line can be drawn from the fossa of the gallbladder to the middle hepatic vein/vena cava, dividing the liver into the anatomic right and left lobe (Fig. 11-3). This imaginary line will often follow the course of the middle hepatic vein.

Right lateral segment

Right lateral segment

Left lateral segment

Right paramedian segment

Left paramedian segment

Left lateral segment

Right paramedian segment

Left paramedian segment

Right lateral segment

Dorsal segment

Getting Back Into Shape After The Pregnancy

Getting Back Into Shape After The Pregnancy

Once your pregnancy is over and done with, your baby is happily in your arms, and youre headed back home from the hospital, youll begin to realize that things have only just begun. Over the next few days, weeks, and months, youre going to increasingly notice that your entire life has changed in more ways than you could ever imagine.

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