Nutrition in human beings or human digestive system

1. Nutrition in Human
beings or the Human
Digestive System
Lecture by: Surbhi Sharma

2. Major nutrients in the diet
– Water
– Carbohydrates
– Proteins
– Fats
– Vitamins
– Minerals
Components of these nutrients
Sugar + Sugar = Carbohydrates
Amino acid+ Amino acids = Proteins
Fatty acids + glycerol = Fats
Vitamins and minerals do not need to be processed into their
simpler forms in order to be utilised by the body.

3. The digestive System /
Alimentary Canal
– Digestion: It is the sequence by which food is broken down and chemically
converted so that it can be absorbed by the cells of an organism and used to
maintain vital bodily functions.
– Digestive system : A long tube extending from the mouth to the anus
– Digestion takes place step by step at various sites in the digestive tract and the
nutrients absorbed are taken to the blood stream and then received by cells

4. Enzymes : These are proteins which help in
chemical reactions to occur to give out specific
products of that biochemical reaction. They
bring about a change in the food substances
without themselves undergoing any change.
Mouth : Saliva salivary amylase (50% of the
digestion should occur in the mouth only)
Food pipe: peristaltic movements
Stomach: expands, has gastric glands which
release Hydrochloric acid, enzyme pepsine and
mucus.
Small intestine is the longest part of the tract,
extensively coiled. site of the complete digestion
of carbohydrates, proteins and fats. Secrets
intestinal juice.
Liver: Bile and bile salts for fat digestion
Pancreas: Trypsin (for proteins) and lipase (for
emulsified fats)
Tongue
Mouth (Buccal cavity)
Oesophagus (Food pipe)
Liver
Gall bladder
Stomach
Pancreas
Small intestine
Large intestine
Appendix
Anus
Rectum

5. The digested food is taken up by the walls of the intestine. The inner lining of the small intestine has
numerous finger-like projections called villi which increase the surface area for absorption.
The unabsorbed food is sent into the large intestine where more villi absorb water from this material. The
rest of the material is removed from the body via the anus.
So following is the path of the food in the digestive tract:
Mouth- Oesophagus Stomach Small intestine Large intestine Rectum Anus

6. Thank
you!