What is the portal area of the liver?

The portal area is the ‘main entrance’ and one of the two main exits of the liver lobule. Through the main entrance portal and arterial blood reach the liver sinusoids. Through the exit the bile flows towards the duodenum.

What is the portal lobule?

A small subunit of the liver composed of cells (hepatocytes) that process blood from an incoming portal venule and send the resulting blood to an outgoing hepatic venule. Focusing on the inflow of blood, the portal lobule is defined to be those cords of hepatocytes that drain blood from an individual portal venule.

How many portal triads does a lobule have?

six portal triads
The liver is a solid organ composed of classical functional units called lobules. Each lobule has six sides with a central vein in the middle of the hexagon and six portal triads at the angles.

What structures make up a portal triad of a liver lobule?

It is equivalent between all three species (Fig. 13.5). Although often referred to as “portal triads,” in all three species, the portal regions actually comprise four components: arterioles, venules, bile ductules, and lymphatics (Fig. 13.6).

What is the function of a liver lobule?

Two common ways are divisions into portal lobules or into liver acini. Portal lobules emphasize the afferent blood supply and bile drainage by the vessels of the portal triads. The secretory function of the liver is emphasized by the term liver acinus.

What does portal tract mean?

Definitions. Although the portal tract is generally viewed as containing a portal vein, hepatic artery, and bile duct,10 portal tracts have at other times been defined by the presence of a portal vein and artery alone. 3 The latter definition is a necessary step for studies of bile duct destructive diseases.

What is a lobule?

The lobule, the fleshy lower part of the auricle, is the only area of the outer ear that contains no cartilage. The auricle also has several small rudimentary muscles, which fasten it to the skull and scalp.

How does a liver lobule work?

These lobules are very small. Each lobule is made up of numerous liver cells, called hepatocytes, that line up in radiating rows. Between each row are sinusoids. These small blood vessels diffuse oxygen and nutrients through their capillary walls into the liver cells.

Is porta hepatis the same as portal triad?

A wide array of pathologic conditions can arise within the porta hepatis, which encompasses the portal triad (the main portal vein, common hepatic artery, and common bile ducts), lymphatics, nerves, and connective tissue.

What contains the portal triad?

The portal triad is contained within the hepatoduodenal ligament and contains the portal vein (posterolateral), hepatic artery (medial), and bile ducts (lateral) (figure 1).

What are liver portal triads?

Portal triads are composed of three major tubes. Branches of the hepatic artery carry oxygenated blood to the hepatocytes, while branches of the portal vein carry blood with nutrients from the small intestine. The bile duct carries bile products away from the hepatocytes, to the larger ducts and gall bladder.

What is the entrance and exit of the liver lobule?

What are hepatic lobules?

Hepatic microscopic architecture in all three species can be described in the context of “classical liver lobules .” These are polygonal structures with portal tracts at the periphery circumscribing a central vein. The human liver is estimated to contain approximately 1 million classical hepatic lobules.

What is the difference between classic lobule and portal lobule?

While the classic lobule view focuses on the blood supply and hepatic mass arrangement, the portal lobule view underlines the exocrine function of the liver i.e. bile secretion.

What is the structure of the liver’s Functional units?

The structure of the liver’s functional units or lobules. Blood enters the lobules through branches of the portal vein and hepatic artery proper, then flows through sinusoids. [edit on Wikidata] The lobules of liver, or hepatic lobules, are small divisions of the liver defined at the microscopic (histological) scale.