1. D.3 Functions of the liver
Understanding:
The liver removes toxins from the blood and detoxifies them
Components of red blood cells are recycled by the liver
The breakdown of erythrocytes starts with phagocytosis of red blood cells by Kupffer cells
Iron is carried to the bone marrow to produce hemoglobin in new red blood cells
Surplus cholesterol is converted to bile salts
Endoplasmic reticulum and Golgi apparatus in hepatocytes produce plasma proteins
The liver intercepts blood from the gut to regulate nutrient levels
Some nutrients in excess can be stored in the liver
Applications:
Causes and consequences of jaundice
Dual blood supply to the liver and differences between sinusoids and capillaries
Nature of science:
Educating the public on scientific claims: scientific studies have shown that high-density lipoproteins could be considered ’good’ cholesterol

2. Label the liver Liver Hepatic vein Hepatic artery Hepatic portal vein
Gall bladder
Right lobe
Left lobe
Applications:
Dual blood supply to the liver and differences between sinusoids and capillaries

4. Hepatic Portal Vein or Hepatic Artery?
Brings blood from the heart
Brings blood from the stomach and intestines
Oxygen rich
Majority of blood in liver uses this path
Very little oxygen
Branches off from the aorta

5. Hepatic Artery Hepatic Portal Vein
Branches off from the aorta
Brings blood from the heart
Oxygen rich
Hepatic Portal Vein
Brings blood from the stomach and intestines
Majority of blood in liver uses this path
Very little oxygen

7. Hepatic portal vein divides into sinusoids
Applications:
Dual blood supply to the liver and differences between sinusoids and capillaries

8. Wider than capillaries and walls not continuously lined with cells
Sinusoids
Wider than capillaries and walls not continuously lined with cells
Applications:
Dual blood supply to the liver and differences between sinusoids and capillaries

9. Sinusoids The blood comes into contact with the hepatocytes
(liver cells)
Hepatic artery branches into arterioles and these join the sinusoids
Applications:
Dual blood supply to the liver and differences between sinusoids and capillaries

10. Sinusoids
Sinusoids then merge with venules that lead to the hepatic vein
Carries blood from the liver to the vena cava
Applications:
Dual blood supply to the liver and differences between sinusoids and capillaries

11. Role of the liver

12. Role of the liver Regulate nutrients in the blood
Absorbs and breaks down toxic substances
Protein synthesis
Storage
Break down of red blood cells

13. Liver processes nitrogenous waste
Regulates Nutrients
Regulates nutrients in the blood
Glucose stored as glycogen
Excess amino acids and proteins broken down and used as energy
Liver processes nitrogenous waste
Understanding:
The liver removes toxins from the blood and detoxifies them

14. Regulates Nutrients Manages lipids circulating in the blood
Lipids broken down and released as other forms
Useful in the body
Understanding:
The liver removes toxins from the blood and detoxifies them

15. Toxic Substances Absorbs toxic substances from the blood
Converts them into non-toxic or less toxic substances
Ammonia  Urea
Understanding:
The liver removes toxins from the blood and detoxifies them

16. Protein Synthesis Hepatocytes produce proteins in blood plasma
Active protein synthesis in hepatocytes
Extensive networks of endoplasmic reticula and Golgi body
Approx 13 million ribosomes attached to the ER of a typical liver cell
Understanding:
Endoplasmic reticulum and Golgi apparatus in hepatocytes produce plasma proteins

17. Storage High blood glucose ________ released
_________ stored as____________
Low blood glucose
_________ released
__________
broken down to__________
Understanding:
Some nutrients in excess can be stored in the liver

18. Storage High blood glucose Insulin released Glucose stored as glycogen
Low blood glucose
_________ released
__________
broken down to__________
Understanding:
Some nutrients in excess can be stored in the liver

19. Storage High blood glucose Insulin released Glucose stored as glycogen
Low blood glucose
Glucagon released
Glycogen broken down to glucose
Understanding:
Some nutrients in excess can be stored in the liver

20. More Storage Iron, retinol (vit A) and calciferol (vit D)
Stored in liver when in excess
Released when a deficit in the blood
Understanding:
Some nutrients in excess can be stored in the liver

21. Erythrocyte break down
Lifespan of a red blood cell (erythrocyte) approximately 120 days
Plasma membrane of old erythrocytes changes to make them recognizable by macrophages
Removed from circulation and broken down in liver
Most products are recycled
Use of Kupffer cells
Understanding:
Components of red blood cells are recycled by the liver

22. Kupffer cells Kupffer cells: macrophages that engulf red blood cells
Line the sinusoids in the liver
Understanding:
The breakdown of erythrocytes starts with phagocytosis of red blood cells by Kupffer cells

23. Kupffer cells
Haemoglobin molecule split into globin chains and a heme group
Amino acids from globin chains are recycled
Heme broken down into iron and bilirubin
Understanding:
The breakdown of erythrocytes starts with phagocytosis of red blood cells by Kupffer cells

24. Erythrocyte breakdown
Bilirubin released into the blood. Eventually filtered out by kidneys or excreted.
Iron bound to protein transferrin and either taken to the liver for storage
May also be taken to the bone marrow to synthesize new blood cells
Understanding:
The breakdown of erythrocytes starts with phagocytosis of red blood cells by Kupffer cells
Iron is carried to the bone marrow to produce hemoglobin in new red blood cells

25. Iron released into cells to create new hemoglobin
Transport of Iron
Iron may be taken to bone marrow to be added to heme groups in new red blood cells
Developing cells have very high levels of transferrin receptors.
Iron released into cells to create new hemoglobin
Understanding:
Iron is carried to the bone marrow to produce hemoglobin in new red blood cells

26. Role of the liver Regulate nutrients in the blood
Absorbs and breaks down toxic substances
Protein synthesis
Storage
Break down of red blood cells

27. Regulate nutrients in the blood Erythrocyte Breakdown
Role of the liver
Regulate nutrients in the blood
Toxic Substances
Erythrocyte Breakdown
Storage
Protein Synthesis

28. Jaundice Build up of bilirubin in blood Normal levels: 1.2mg/dl
Jaundice: 2.5mg/dl +
What are the symptoms?
Why might a newborn be susceptible to jaundice?
How can it be treated?
Applications:
Causes and consequences of jaundice

29. Jaundice Skin and eyes discolored (yellow)
Build up of Bilirubin in the blood
Jaundice is not a disease itself but is a symptom of an underlying disease of the liver
Applications:
Causes and consequences of jaundice

30. Jaundice
Newborns have a high turnover of red blood cells (lots being broken down)
Liver still developing and cannot break down bilirubin fast enough
May not be able to feed properly – cannot egest the bilirubin quickly
Applications:
Causes and consequences of jaundice

31. Jaundice
Treatment to remove bilirubin can be done by exposing to UV light
Converts bilirubin to products that can be excreted easily
Underlying cause still needs to be addressed to stop the jaundice
Applications:
Causes and consequences of jaundice

32. Outline two roles of the liver (2)
Exam Qs
Outline two roles of the liver (2)
Describe the process of erythrocyte and hemoglobin breakdown in the liver (4)

33. Exam Q 1 Outline two roles of the liver (2) storage of nutrients;
detoxification of poisons;
breakdown of hemoglobin;
production of bile pigments;
synthesis of plasma proteins;
synthesis of cholesterol;
regulation of nutrients in the blood;

34. Exam Q 2
Describe the process of erythrocyte and hemoglobin breakdown in the liver (4)
erythrocytes rupture when they reach the end of their life span /after 120 days;
absorbed by phagocytosis / Kupffer cells in liver from blood;
hemoglobin split into globin and heme groups;
iron removed from heme leaving bile pigment / bilirubin;
bilirubin released into alimentary canal;
digestion of globin to produce amino acids; ;

35. Cholesterol

36. Cholesterol Absorbed from food in the intestine
Also synthesized by hepatocytes
Needed for the synthesis of Vitamin D and steroid hormones
Needed as a structural component of membranes
Used in production of bile
Understanding:
Surplus cholesterol is converted to bile salts

37. High Density of Low Density Lipoproteins.
Cholesterol
High Density of Low Density Lipoproteins.
What are these?
Which are good and which are bad?
Why?
What evidence is there to back this up?
Nature of science:
Educating the public on scientific claims: scientific studies have shown that high-density lipoproteins could be considered ’good’ cholesterol