1. Liver Anatomy
Figure 21-19: The hepatic portal system

2. IB ASSESSMENT STATEMENT
H.4.1 Outline the circulation of blood through liver tissue, including the hepatic artery, hepatic portal vein, sinusoids and hepatic vein.

3. Blood and Bile Flow Through the Liver

5. Blood flow of the Liver
Hepatic Artery delivers oxygenated blood to the liver.
Blood leaves the liver by the hepatic Vein
Hepatic portal vein bring blood to the liver from the small intestine.

6. Blood Flow in the Liver
Arterial blood mixes with that from the hepatic portal vein as it flows through the blood-filled channels known as the sinusoids.
Sinusoids differ from capillaries because there are no walls separating the blood from the liver cells.
Thus blood are indirect contact with the blood cells
The sinusoids are lined with phagocytic cells that ingest old red blood cells

7. Blood flow in the Liver Animation

10. Structure of Liver Animation

11. IB Assessment Statements
H.4.3 Explain the role of the liver in regulating levels of nutrients in the blood.
H.4.4 Outline the role of the liver in the storage of nutrients, including carbohydrate, iron, vitamin A, and vitamin D.

12. Functions of the Liver Storage
Glycogen, fat, vitamins, copper and iron. Hepatic portal blood comes to liver from small intestine.
Nutrient interconversion
Amino acids to energy producing compounds
Hydroxylation of vitamin D. Vitamin D then travels to kidney where it is hydroxylated again into its active form

17. Liver as a storage organ
Liver stores:
Iron
Carbohydrates (glycogen)
Fat Soluble Vitamins (A, B12, D, and K)

18. IB Assessment Statement
H.4.5 State that the liver synthesizes plasma proteins and cholesterol

19. Functions of the Liver Synthesis
Albumins, fibrinogen, globulins, heparin, clotting factors

22. IB Assessment Statement
H.4.7 Describe the process of erythrocyte and hemoglobin breakdown in the liver, including phagocytosis, digestion of globin and bile pigment formation.

24. Composition of Bile
A yellow-green, alkaline solution containing bile salts, bile pigments, cholesterol, neutral fats, phospholipids, and electrolytes
Bile salts are cholesterol derivatives that:
Emulsify fat
Facilitate fat and cholesterol absorption
Help solubilize cholesterol

25. Regulation of Bile Release
Figure 23.25

26. Bile Flow around the Liver
Bile is completely isolated from the blood via bile channels
Bile channels are composed of two rows of liver cells
Bile is produced in the liver and brought to the gall bladder for storage via the bile ducts.
Bile ducts are channels that carry bile.

28. IB Assessment Statement
H.4.8 Explain the liver damage caused by excessive alcohol consumption

29. H.4.7: Liver damage caused by excessive alcohol consumption
Liver damage occurs as a result of excessive and prolonged alcohol use.
There are three stages of liver damage which includes fat accumulation leading to liver inflammation then cirrohsis of the liver.
The breakdown of alcohol occurs in the liver and the resulting breakdown products of alcohol are toxic to the liver cells.

32. IB Assessment Statement
H.4.6 State that the liver has a role in detoxification.

33. Functions of the Liver
Bile production: mL/day. Bile salts (bilirubin), cholesterol, fats, fat-soluble hormones, lecithin
Neutralizes and dilutes stomach acid
Bile salts emulsify fats. Most are reabsorbed in the ileum.
Secretin (from the duodenum) stimulates bile secretions, increasing water and bicarbonate ion content of the bile
Storage
Glycogen, fat, vitamins, copper and iron. Hepatic portal blood comes to liver from small intestine.
Nutrient interconversion
Amino acids to energy producing compounds
Hydroxylation of vitamin D. Vitamin D then travels to kidney where it is hydroxylated again into its active form
Detoxification
Hepatocytes remove ammonia and convert to urea
Phagocytosis
Kupffer cells phagocytize worn-out and dying red and white blood cells, some bacteria
Synthesis
Albumins, fibrinogen, globulins, heparin, clotting factors