3In the small intestines Complete digestion occurs in the small intestinesEnd products (glucose, amino acids, fatty acids, glycerol) diffuse into the blood vessels lining the small intestines.This process is called Absorption.
4Guess what is the organ shown! From which animal? Some animal samplesGuess what is the organ shown!From which animal?
9How do the folds and villi help in absorption? The presence of folds and villi in the intestinal wall increase surface area
10More adaptations from the small intestine the epithelial cell of the intestinal wallOne-celled thick epithelial wall and microvilli further increases surface area
11The small intestinesWhat makes the small intestines suitable for Absorption?2) Villi andmicrovilli1) Elongated ileum, Inner surface of the ileum is foldedThese features provide large surface area:vol for absorption
12The small intestinesWhat makes the small intestines suitable for Absorption?3) Many blood vessels lining the small intestines
13Absorption Absorption occurs by: After absorption, Diffusion Active transportAfter absorption,Glycerol and fatty acids enter the lactealsGlucose and amino acids enter the blood capilliaries
14How does absorption takes place in the intestines Absorption of fatty acids and glycerolGlycerol and fatty acids diffuse into the epithelium where they combined to form minute fat globules and enters the lactealsFat globules mix with lymph in the lacteals to form chyleLiver is not involved *
18Lesson 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 bodyRegulation of blood glucose concentrationDeamination of amino acidsProduction of bileDetoxicationIron storage
28Carbohydrate metabolism In the liver….Some glucose carried in the blood to be distributed to the rest of the bodyTissue respiration
29-Glucose (excess) Glycogen (stored) Insulin and glucagonIn the liver….-Glucose (excess) Glycogen (stored)Hormone : InsulinIf the glucose level is too low in the bloodGlycogen (stored) GlucoseHormone: Glucagon
30What about the amino acids absorbed by the small intestines? Similar route as sugars:Intestines hepatic portal vein liver general blood circulation
32Amino acid metabolismFate of amino acidsConverted into protoplasmUsed for growth & repair of worn-out partsFormation of enzymes & hormonesExcess amino acids cannot be stored : Deamination
33Deamination H O | H || —C— C—OH —N— R Amino group Carbon residue Ammonia (toxic)glucoseUrea (non-toxic)glycogen
34Fat metabolism Fate of Fats (Liver not involved)Intestines lacteal lymphatic vessels blood rest of the bodyFate of Fatsmaintenance of cell membranesProduction of hormonesExcess fats stored in adipose tissuesWhen glucose supply is low, fats will be oxidised in the liver to provide energy
35Summary: 5 major roles that the liver plays Regulation of blood glucose concentrationDeamination of amino acidsIron storageProduction of bileDetoxication