Human Nutrition

1. Human Nutrition Grade 11 2019 – Flipped Classroom resource

2. What I want you to do? • In groups of 3 or 4 prepare 6 essays in Google Docs using this PPT as well as other linked resources to help you. • Textbook: Shuters Top Class pg 121 – 139 only • Explore the journey of food along the alimentary canal from large molecules to smaller molecules. • 4 Parts to this journey • Describe structure and function of all parts of the digestive system • Explain digestive all processes including enzyme activity • Adaptations of small intestine and the role of the liver • Homeostasis of glucose

3. Animal Nutrition • Food gives organisms energy for all cellular functions. • Producers/autotrophs • Consumers/heterotrophs: • Herbivores • Carnivores • Omnivores

4. Part 1: Structure and Function Overview • Eyes, Nose and tongue • Mouth and teeth • Oesophagus • Stomach • Small Intestine (duodenum, jejunum and ileum) • Colon/Large Intestine • Rectum and anus • Salivary glands • Liver and gall bladder • Pancreas Click movie icon to start Introduction to Digestion Video!

5. Sensing food and the mouth, tongue and teeth • All starts with the senses in the body! • Mouth: • Beginning of the Big Mac’s journey • Tongue and teeth inside the mouth • Tongue tastes food and helps you swallow • Teeth break up food into smaller pieces = mechanical digestion/mastication • 3 pairs of salivary glands that produce saliva: • Water, slippery mucin and enzymes (lysozyme and salivary amylase) • Helps to form bolus and lubricate it for swallowing Sense of taste and smell video Teeth video

6. Structure: Teeth • 4 types: • Incisors • canines • premolars • Molars • Humans • 2:1:2:3 2:1:2:3 • Textbook Pg 123 & 131 Q1:Which set of teeth belongs to which type of consumer and give reasons why?

7. Passed the pharynx, through the oesophagus • Pharynx (throat): • Muscular part at the back of mouth • Opens to trachea (to the lungs) and oesophagus (to the stomach) • Oesophagus: • Narrow muscular tube • Bolus moves down through contraction and relaxation of muscles in process called = PERISTALSIS Q2:Can you think of other examples in the body where peristalsis is used to move things? Textbook Pg 133

8. Into the stomach • Large ‘bag’ that receives and holds food. • At each end of the stomach there are valves called sphincters that control the movement of food; • Cardiac sphincter at the top end • pyloric sphincter at the bottom end • Cells lining the stomach secrete gastric juice. • Hydrochloric acid (HCl), low pH • Mucus, high pH • Proteases, (pepsinogen) • Alcohol, Vit B12 and aspirin are absorbed. • Food leaves the stomach as chyme. Stomach video

9. Into the not so… small intestine • Soupy chyme enters small intestine. • Folded tube (5 -7m long) • Lined with columnar epithelial cells • 3 parts: • Duodenum • Jejunum • Ileum • Duodenum has Brunner’s glands which secrete alkaline rich mucus; • NeutraliseChyme • Provide right pH for enzymes • Lubrication • Digestion of food is completed so that simple soluble nutrients can be absorbed. • Carbohydrates, fats and proteins are digested • Most digested food absorbed Small intestine video

10. Large intestine • Large intestine/colon stretches like a frame around the small intestine. • Main functions: • Absorb water, dissolved minerals and vitamins • Helped by over 700 species of bacteria (gut flora) • Caecum and appendix are two structures where small intestine joins large intestine; • No digestive function but contain tissue from the immune system • Very large in organisms that digest cellulose • Rectum is short tube at end of large intestine; • Stores indigestible remains for short time before being expelled • At the opening end of rectum is anus; • Surrounded by sphincter muscles to help control movement of faeces Large intestine video

11. Associated glands: Salivary Glands and Pancreas • 3 salivary glands that secrete saliva. • Pancreas that secretes pancreatic juice. • Travels down duct into duodenum (exocrine gland) • Contains enzymes for breaking down food • Carbohydrases: starch maltose • Proteases: proteins amino acids • Lipases: lipids fatty acids and glycerol • Contains alkaline salts for neutralising acidic chyme • Pancreas controls blood sugar levels by secreting hormones insulin and glucagon (endocrine gland).

12. Associated glands: Liver • Largest gland and solid organ in the body. • Liver has many functions: • Secretes bile which is stored in gall bladder. • Bile neutralises acidic chyme • Emulsifies fats into small droplets • Controls release of glucose in blood by converting glucose glycogen. • Controls excessive amino acid concentrations in the body through deamination. • Process where amine group is removed from amino acid producing a carbohydrate and urea. • Transports both glucose and amino acids if necessary via hepatic vein (vessel from liver to heart) to the heart and then to cells of the body. • Store vitamins and minerals (if not needed pass out through urine). • Alcohol and drugs are transported via hepatic portal vein (vesselfrom small intestine or stomach to the liver) to be metabolised. Liver fact pack

13. Part 1: Structure and Function Textbook page 125

14. Cultural and socio-economic influences on diet Italy: The Manzo family of Sicily R 1976 per week

15. Germany: The Melander family of Bargteheide R 3712 per week

16. United States: The Revis family of North Carolina. R 2538 per week

17. Mexico: The Casales family of Cuernavaca R 1403 per week

18. Poland: The Sobczynscy family of Konstancin-Jeziorna R 1123 per week

19. R 507 per week Egypt: The Ahmed family of Cairo

20. Ecuador: The Ayme family of Tingo R 234 per week

21. Bhutan: The Namgay family of Shingkhey Village R 37 per week

22. Chad: The Aboubakar family of Breidjing Camp R 9.13 per week

23. Thank yougnoel@bishops.org.za