1. Liver Functions Part II

2. From where we left off…

3. In the small intestines
Complete digestion occurs in the small intestines
End products (glucose, amino acids, fatty acids, glycerol) diffuse into the blood vessels lining the small intestines.
This process is called Absorption.

4. Guess what is the organ shown! From which animal?
Some animal samples
Guess what is the organ shown!
From which animal?

6. Adaptation of the small intestine for absorption

7. Structure of small intestine
Blood vessels (capillaries) combine to form a large blood vessel which carries food to the liver.

8. What do you see in the intestinal walls?

9. How do the folds and villi help in absorption?
The presence of folds and villi in the intestinal wall increase surface area

10. More adaptations from the small intestine
the epithelial cell of the intestinal wall
One-celled thick epithelial wall and microvilli further increases surface area

11. The small intestines
What makes the small intestines suitable for Absorption?
2) Villi and
microvilli
1) Elongated ileum, Inner surface of the ileum is folded
These features provide large surface area:vol for absorption

12. The small intestines
What makes the small intestines suitable for Absorption?
3) Many blood vessels lining the small intestines

13. Absorption Absorption occurs by: After absorption, Diffusion
Active transport
After absorption,
Glycerol and fatty acids enter the lacteals
Glucose and amino acids enter the blood capilliaries

14. How does absorption takes place in the intestines
Absorption of fatty acids and glycerol
Glycerol and fatty acids diffuse into the epithelium where they combined to form minute fat globules and enters the lacteals
Fat globules mix with lymph in the lacteals to form chyle
Liver is not involved *

15. Assimilation and function of the liver

16. Overview Role of Digestion Mouth & Oesophagus Stomach
Large Intestine & Others
Gall Bladder &Pancreas
Small Intestine

17. Overview – 4 Stages
Ingestion
Digestion
Assimilation
Absorption

18. Lesson objectives:
Describe the fate of glucose, amino acids and fats in the blood that leaves the intestines, after a meal.
Describe the 5 major roles that the liver plays in the human body
Regulation of blood glucose concentration
Deamination of amino acids
Production of bile
Detoxication
Iron storage

19. Fate of glucose and amino acids

20. Assimilation Transport and utilization of absorbed foods In the Liver!
Types of absorbed food products
Glucose
Amino acids
Fats

21. From the small intestines to the liver! How??
Connected by a vein called Hepatic Portal Vein!

22. Guess which part the vein connects to the intestine?B C D A

24. Carbohydrate metabolism
Hepatic portal vein
transports sugars like glucose from the intestines to the liver

25. Question! Requires only 3 glucose molecules for breathing
Receives 5 glucose molecules from the intestines

26. how many molecules of glucose do you think the liver would transport to the lungs?
Requires only 3 glucose molecules for breathing
Receives 5 glucose molecules from the intestines

27. Liver in Glucose metabolism
Hepatic portal vein

28. Carbohydrate metabolism
In the liver….
Some glucose carried in the blood to be distributed to the rest of the body
Tissue respiration

29. -Glucose (excess)  Glycogen (stored)
Insulin and glucagon
In the liver….
-Glucose (excess)  Glycogen (stored)
Hormone : Insulin
If the glucose level is too low in the blood
Glycogen (stored)  Glucose
Hormone: Glucagon

30. What about the amino acids absorbed by the small intestines?
Similar route as sugars:
Intestines  hepatic portal vein  liver  general blood circulation

31. Liver in Protein metabolism
Hepatic portal vein

32. Amino acid metabolism
Fate of amino acids
Converted into protoplasm
Used for growth & repair of worn-out parts
Formation of enzymes & hormones
Excess amino acids cannot be stored : Deamination

33. Deamination H O | H || —C— C—OH —N— R Amino group Carbon residue
Ammonia (toxic)
glucose
Urea (non-toxic)
glycogen

34. Fat metabolism Fate of Fats
(Liver not involved)
Intestines  lacteal  lymphatic vessels  blood  rest of the body
Fate of Fats
maintenance of cell membranes
Production of hormones
Excess fats stored in adipose tissues
When glucose supply is low, fats will be oxidised in the liver to provide energy

35. Summary: 5 major roles that the liver plays
Regulation of blood glucose concentration
Deamination of amino acids
Iron storage
Production of bile
Detoxication

36. True/False
Liver is part of the alimentary canal

37. True/False
Carbohydrates are digested in the liver

38. True/False
Excess amino acids are deaminated

39. True/False
Fats are absorbed in the liver and transport to other parts of the body for usage.