True or false, the liver is the smallest organ in the body.
False, it is the largest.
What is the function of the liver?
- Major metabolic organ
- Degrades alcohol and drugs
- Secretes bilirubin
- Secrete bile salts (which emulsify fats to aid digestion)
- Stores glycogen
Triple SMD to live
Describe the blood supply of the liver.
- Dual blood supply
- Receives blood from the hepatic artery and receives blood from the hepatic portal vein which contains nutrients absorbed from the GI tract.
- After leaving the liver, it exits via the hepatic vein.
How many lobes is the liver divided into?
2 lobes, separated by middle hepatic vein. The right is larger than the left.
Describe the layers of the liver.
- Thin capsule of dense connective tissue around the liver
- Visceral (inferior layer)
- Peritoneal mesothelium (outer layer, superior to capsule)
What is a portal tract?
Blood flows to and exits the liver via the portal tract. Consist of a bile duct, portal vein, hepatic artery and lymphatic duct.
What are hexagonal lobules in the liver?
The functional unit of the liver. The liver is separated into these lobules working in sync with each other.
What are portal triads?
- The 3 vessels - bile duct, hepatic venule and hepatic arteriole all together in bunches that surround the hexagonal lobule.
- On each corner of the hepatic lobule
- The branch of the portal vein is always the largest (carries blood at low pressure)
- Bile duct branch is the smallest
What are sinusoids?
These are the passages/tunnels in the hexagonal lobule that drain the blood from the portal triad into the centre also known as central veins.
What is the space between the sinusoids and hepatocytes called?
The space of Disse, which is where interstitial fluid can leak to. This can be drained via the lymphatic duct.
What macrophage is found in the liver?
Kupfer cells
What is bile produced by and how is it drained?
Bile is produced from hepatocytes and drained via bile canaliculi.
What is the name given to the vessel formed when central veins combine?
Interlobular veins that take blood to the hepatic vein then vena cava.
Is the liver exocrine or endocrine?
The liver is both exocrine and endocrine glands; they are exocrine glands because they secrete products—bile into the gastrointestinal tract through a series of ducts, and endocrine because they secrete other substances directly into the bloodstream.
What is the portal triad surrounded by?
Interlobular connective tissue.
Describe hepatocytes.
- Make-up about 80% of the liver
- Round with often 2 nuclei (an easy way to identify liver cells) or could have 1 nucleus.
- produce bile
- store glycogen
- lots of mitochondria
