Liver Functions
Mission 1:
Mission Objectives. You should be able to...
1. Describe how the liver cleans the blood.
2. Explain the purpose and function of hepatocytes and Kupffer cells.
3. Recall how the liver regulates the amount of glucose in the blood.
4. Describe the role of bile in digestion.
The liver receives blood from the hepatic portal vein and the hepatic artery. The HPV carries deoxygenated blood rich with nutrients. The HA carries oxygenated blood from the heart.
The HPV receives its blood from the capillaries within the villi of the small intestine. The stabilization of nutrients within the HPV represents one of the major functions of the liver, specifically the storage of nutrients and the release of those nutrients when needed.
The function of the liver is to at once add substances to and remove substances from the blood. Liver cells (hepatocytes) are responsible for this. Sinusoids are the specialized capillary beds inside the liver and are where exchanges between the blood and the hepatocytes take place. Sinusoids differ from standard capillaries in several ways. Refer to page 513 to see a list of how they differ.
The liver removes toxins from the blood. It does this using hepatocytes and specialized leukocytes called Kupffer cells. Kupffer cells line the inside of sinusoids and use phagocytosis to remove old erythrocytes and bacteria from the blood. They contain many lysosomes (which are the organelles responsible for breaking down waste). Hepatocytes are the most active in removing and processing chemical toxins from the blood.
Blood plasma flows over and through hepatocytes and the hepatocytes remove toxins from the plasma by (1) chemically modifying the toxin to make it less destructive, and (2) adding chemical components that make the toxin water-soluble.
Mission Objectives. You should be able to...
1. Describe how the liver cleans the blood.
2. Explain the purpose and function of hepatocytes and Kupffer cells.
3. Recall how the liver regulates the amount of glucose in the blood.
4. Describe the role of bile in digestion.
The liver receives blood from the hepatic portal vein and the hepatic artery. The HPV carries deoxygenated blood rich with nutrients. The HA carries oxygenated blood from the heart.
The HPV receives its blood from the capillaries within the villi of the small intestine. The stabilization of nutrients within the HPV represents one of the major functions of the liver, specifically the storage of nutrients and the release of those nutrients when needed.
The function of the liver is to at once add substances to and remove substances from the blood. Liver cells (hepatocytes) are responsible for this. Sinusoids are the specialized capillary beds inside the liver and are where exchanges between the blood and the hepatocytes take place. Sinusoids differ from standard capillaries in several ways. Refer to page 513 to see a list of how they differ.
The liver removes toxins from the blood. It does this using hepatocytes and specialized leukocytes called Kupffer cells. Kupffer cells line the inside of sinusoids and use phagocytosis to remove old erythrocytes and bacteria from the blood. They contain many lysosomes (which are the organelles responsible for breaking down waste). Hepatocytes are the most active in removing and processing chemical toxins from the blood.
Blood plasma flows over and through hepatocytes and the hepatocytes remove toxins from the plasma by (1) chemically modifying the toxin to make it less destructive, and (2) adding chemical components that make the toxin water-soluble.
Using what you have learned, determine how and why alcohol consumption damages liver cells.
Remember from Chapter 6 how the liver regulates the amount of glucose in the blood? Insulin and glucagon are secreted from the pancreas. If there is an abundance of glucose in the blood, insulin is produced and stimulates hepatocytes to turn the excess glucose into glycogen and store it in the liver. If there is not enough glucose, then glucagon is produced and stimulates hepatocytes to convert the glycogen into glucose.
Table 10.2 (p. 515) shows the nutrients stored by the liver.
Remember from Chapter 6 how the liver regulates the amount of glucose in the blood? Insulin and glucagon are secreted from the pancreas. If there is an abundance of glucose in the blood, insulin is produced and stimulates hepatocytes to turn the excess glucose into glycogen and store it in the liver. If there is not enough glucose, then glucagon is produced and stimulates hepatocytes to convert the glycogen into glucose.
Table 10.2 (p. 515) shows the nutrients stored by the liver.
The liver recycles parts of erythrocytes and hemoglobin. Kupffer cells break down hemoglobin into its component parts: four polypeptides, four heme groups and four iron atoms. The remaining molecule is called bilirubin or bile pigment. The liver produces bile, which is added to the duodenum when fatty foods are being digested. The addition of bile makes it easier for fats to be broken down.
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Hepatocytes also produce albumin and fibrinogen. Albumin regulates blood osmotic pressure and acts as a carrier for bile salts and other fat-soluble substances. Fibrinogen, when converted to fibrin, forms the mesh component of a blood clot.
This video from Khan Academy goes into detail about liver functions.
This video from Khan Academy goes into detail about liver functions.