nutrition
DIET              Means what you eat  The food is the source of raw materials that      needed to make new substances for:...
carbohydrates    Classes of               Diet  carbohydrates            Problems- Monosaccharides   Excessive   Deficient...
Carbohydrates• Carbohydrates are good source of energy &• it supplies most of the energy that we need.• It is made up of t...
Monosaccharides are carbohydrates which    cannot be broken down into simpler forms.           Glucose       Fructose     ...
Disaccharides are created when two        monosaccharides become linked.              Sucrose       Maltose     Lactose   ...
sugar• Sugars are used to make  chocolates, candies, soft  drinks and cakes.• Excess carbohydrates in  the body are conver...
Polysaccharides are long chains of monosaccharidesand are the most common carbohydrates in nature.               Storage  ...
starch• Starch is found in food such as rice, potatoes, bread,  cereals, noodles, yam, cassava, beans and grains.
DIET PROBLEMSObesity      Anorexia
OBESITY• Excess carbohydrates  are turned into fats and  stored under the skin  which will cause  someone to be  overweigh...
Stroke            Other              complications              due to obesity         Blood vessel damage           (arte...
ANOREXIA• Someone who is  seriously  underweight is  called anorexic.• This happen when  they don’t eat or eat  less than ...
fats     Types of Fats             Diet ProblemsSaturated   Unsaturated     Excessive    Deficient   Fats        FatsAnima...
fats• Fats give more than   twice the energy as   the same amount of   carbohydrates.• Functions of fats: - reserve supply...
• Fats are obtained from 2 main sources:(a) Animals    - milk, cheese, butter and eggs.(b) Plants    - peanut oil, palm oi...
Are fats bad for us?             Not all fats are bad for              our health. There are                  2 types of f...
Saturated fats       Unsaturated fatsFound in     Cheese, butter,      Vegetable oil, olive             animal fats, egg  ...
DIET PROBLEMSObesity & Heart attack   Anorexia
HEART ATTACK• Fats can caused  someone to be obese.• Some fats can block  our blood vessels in  the heart and cause  heart...
Blood clotBlood clot                       blocks  blocks                       blood flowblood flow             Heart    ...
ProteinsConstituent of        Diet Problems   protein                 Excessive     Deficient                  Gout       ...
Proteins• It consists of long  chains of amino acids  which are made up of  the elements carbon,  hydrogen, oxygen and  ni...
• They are essentials for  growth and repair of worn-  out parts of our bodies.• Muscles, tendons and  cartilage in our bo...
Proteins can be obtained from meat, eggs,       fish, milk, cheese, and beans
DIET PROBLEMSGout      Kwashiorkor
GOUT• Proteins are broken  down to amino  acids.• Excess of amino  acids will be turned  into uric acids.• These uric acid...
Swollen and     Masses ofinflamed joint   uric acids                    Uric acid                    crystals
Normal   Kwashiorkor  KWASHIORKOR• This condition  affects most of the  children from poor  countries.• Such children  usu...
fibres  Importance     Diet ProblemsBowel movement   Constipation
Fibers• Fiber is made up of  cellulose which cannot  be broken down by our  bodies.• The right amount of  fiber in our die...
• Vegetables, fruits,  brown rice, cereals,  whole wheat bread  are examples of food  which are rich in fiber.
Animals such as cows,sheep and goats are called ruminants. They are able  to digest cellulose with   the help of bacteria ...
Vitamins     Types of Vitamins         Diet ProblemsWater-soluble    Fat-soluble- Vitamin B     - Vitamin A- Vitamin C    ...
vitamins• Vitamins are needed in  small amounts by our  bodies for health and  growth.• Vitamins are classified  according...
VITAMIN A
Functions:
Deficiency Problems:                Night blindness
Dry and scaly skins
VITAMIN B1
Functions:
DeficiencyProblem:In severe thiamin deficiency, braindamage can occursuch as Korsakoff  syndrome and    Wernickes     dise...
VITAMIN B2
Functions:
Deficiency Problem: Normal amount       Anemic amountof red blood cells   of red blood cells
VITAMIN B3
Functions:
DeficiencyProblem:
VITAMIN B6
Functions:
DeficiencyProblems:• Confusion• Depression• Irritability
VITAMIN B12
Functions:
Deficiency Problem: Normal amount       Anemic amountof red blood cells   of red blood cells
VITAMIN C• Sources:  - citrus fruits (oranges,    lemons), guavas, green    vegetables, tomatoes
Functions:
DeficiencyProblems:
VITAMIN D
Functions:
DeficiencyProblems:
Ricket- Abnormal formation  of the bones
VITAMIN e
Functions:
VITAMIN K
Function:   Promotes clotting of blood
Deficiency Problems:- bruises easily- prolonged bleeding
VITAMINS OVERDOSEVitamin pills are needed for certain groups such as youngchildren, senior citizen and pregnant women. Mos...
DEATH !!!       A group of Italian            explorers, who had run            out of food ate the liver            of a ...
mineralsTypes of minerals   Importance    Diet Problems   - Calcium        To maintain   - Iron             health   - Iod...
Minerals• Minerals are substances  needed by the body in  tiny amounts for proper  growth and  development.• They are need...
CALCIUM• Functions:  - building strong   bones and teeth  - muscles growth    and contraction  - clotting of blood• Source...
• Deficiency problems:  - rickets
IRON• Functions:  - make haemoglobin   (the red pigment in    red blood cells)• Sources:  - liver, meat, green   vegetable...
• Deficiency problems:  - anaemia    (low count of red     blood cells)
IODINE• Functions:  - make hormones of    the thyroid gland• Sources:  - seafood, seaweed,    green vegetables
• Deficiency problems:  - goitre (swelling of    the thyroid gland in    the lower neck)
SODIUM• Functions:   - regulating our body    fluids• Sources:   - common salt    (sodium chloride)• Excessive problem:  -...
water   Importance             Factors of intake:- to dissolve things                       Activity    Environment- fills...
Water• Water plays vital roles  in many life processes.• Almost 70% of our  bodies are made up of  water.• We can survive ...
• Water is needed for:  - To dissolve things so they     can be carried around our     bodies  - Fills up the cells so the...
• The amount of water needed in the body  depends on:• (a) The activity of the person•    - people who are very active req...
(b) The environmental conditions  - people who live in hot conditions need more    water than those who are in colder envi...
• Water is lost from body daily during breathing, in  the urine, the feces and through sweating.• To balance out the amoun...
FOOD TESTS
FOOD TESTS CARBOHYDRATES         FATS      PROTEINSSTARCH    SUGARS      Emulsion    Biurets                        test  ...
IODINE TESTTo test the presence of starch   Iodine + starch → blue black  (orange)            solution                    ...
Benedicts test To test the presence of     reducing sugars Benedict’s solution + food    (blue)   Heated in water bath    ...
BIURETs testTo test the presence of protein    Biuret’s solution + food        (clear)          Shake well           Posit...
emulsion test To test the presence of fats      Ethanol + food      (clear)    Heated in water bath         (5 mins)      ...
BALANCED DIET               Sugar, fats   Oils, fats, salts, sweets       Proteins, fats              Meat, beans, nuts,  ...
A Balanced diet A balanced diet contains the right amount of energy,carbohydrates, proteins, fats, fibre, vitamins, minera...
ENERGY REQUIREMENTS• Different individuals need  different amounts of  energy.• The factors that affect  energy requiremen...
AGE GROUPA teenager and an adult need more energy         than a child or a baby Children                      Adults
BODY SIZEA big person needs more energy     than a smaller person
GENDER    A boy needs more energy than a girl.A male adult needs more energy than a woman.
ACTIVITYAn active person needs more energy     than a less active person.
ENVIRONMENTA person from a cold environment needs moreenergy than a person from a warm environment
HEALTHA sick person needs more nutrients       than a healthy person
SPECIAL NEEDSA growing child needs plenty of proteins  for making new tissues and growth
SPECIAL NEEDS        A pregnant lady needs         extra proteins, iron           and calcium for          developing fetus.
SPECIAL NEEDS          An athlete needs        proteins for building         muscles and plenty          of simple sugars ...
Digestion
digestion• Digestion is the process  of breaking down large  food molecules into  smaller molecules that  can be readily a...
Human digestive system                                      Mouth    Mouth                      Tongue         Pharynx  Es...
TYPES OF DIGESTION   Physical Digestion        Chemical Digestion Mechanical breakdown        Involves the use ofof food b...
Enzymes• Enzymes are special  types of proteins  produced by our  body for bringing  about and speeding  up chemical  reac...
• Different types of digestive enzymes help to break  down different nutrients into smaller and soluble  molecules• Enzyme...
Substrate                            Products                     Bonds in the substrate                        are weaken...
Process    ofDigestion
DIGESTION IN MOUTH• Food is broken down  into smaller pieces by  the teeth.• Breaking up the food  into smaller pieces  in...
• Saliva contains salivary amylase (an enzyme)  which catalyses the breakdown of starch into  maltose molecules.• However,...
• The tongue rolls  the partially  digested food  into small balls  called bolus  before  swallowing.• Then the tongue  pu...
OESOPHAGUS (GULLET)• Oesophagus is a  narrow tube with  strong muscles in  its wall, connecting  the mouth and the  stomac...
• Peristalsis is  the involuntary  wave-like  muscular  contraction and  relaxation in  the esophagus.       Muscular     ...
DIGESTION IN STOMACH• The stomach have           Oesophagus     Fundus  sphincter muscles to                              ...
• Stomach secretes gastric juices which contains  hydrochloric acid and proteases• Functions of hydrochloric acid are :  •...
• The gastric enzymes are produced as inactive  proteases• Proteases catalyse the breakdown of proteins into  polypeptides...
• Mucus in the stomach  protects the stomach  wall from being  destroyed by acid and  proteases.• Food is then gradually  ...
THE LIVER• The main function of  liver in digestion is  to produce bile.• Bile is a brownish-                            L...
PANCREAS• Pancreas produces  pancreatic juice  which is released                Pancreas  into the duodenum               ...
DIGESTION IN DUODENUM• The duodenum Bile from         Bile from  connects the     gallbladder      liver  stomach & the  s...
• Functions of bile:  - Neutralizes acidic                             Lipid   Bile    chyme from stomach                 ...
 Functions of pancreatic juice are:    - Neutralizes acidic chyme    - Contains digestive enzymes: Enzyme              Ac...
DIGESTION IN SMALL INTESTINE• The small intestine consists  of three sections:         DUODENUM    connects to the stomach...
• Tiny glands in small intestine produce intestinal juice  which contains several types of digestive enzymes:   Enzyme    ...
SMALL INTESTINE                  VILLI                          Veins to                          the liverLayers of      ...
ABSORPTION OF DIGESTED FOOD• Absorption is the movement  of digested food through the  wall of small intestine.• It takes ...
• The villi increase the  surface in contact with  the digested food, so it  can absorb faster.• The walls of small       ...
LARGE INTESTINE• Large intestine does  not secrete any  enzyme.                             Large• Water, minerals and    ...
• This process of discarding  faeces through anus is  called defecation.• If the undigested food  passes through the large...
Nutrition
Nutrition
Nutrition
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Nutrition

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Nutrition

  1. 1. nutrition
  2. 2. DIET Means what you eat The food is the source of raw materials that needed to make new substances for: Energy Growth and Health(helps us to move) repair
  3. 3. carbohydrates Classes of Diet carbohydrates Problems- Monosaccharides Excessive Deficient- Disaccharides- Polysaccharides Obesity Anorexia
  4. 4. Carbohydrates• Carbohydrates are good source of energy &• it supplies most of the energy that we need.• It is made up of the elements of carbon,• oxygen and hydrogen.• Carbohydrates can be divided into 3 groups: (a) Monosaccharides - glucose, fructose and galactose (b) Disaccharides - maltose, lactose and sucrose (c) Polysaccharides - starch, glycogen, cellulose
  5. 5. Monosaccharides are carbohydrates which cannot be broken down into simpler forms. Glucose Fructose GalactoseFound in Sugar Sweet fruits Milk
  6. 6. Disaccharides are created when two monosaccharides become linked. Sucrose Maltose Lactose (Glucose + (Glucose + (Glucose + Fructose) Glucose) Galactose)Found in Sugarcane, Sprouting Milk sweet fruits grains
  7. 7. sugar• Sugars are used to make chocolates, candies, soft drinks and cakes.• Excess carbohydrates in the body are converted by the body into fats.
  8. 8. Polysaccharides are long chains of monosaccharidesand are the most common carbohydrates in nature. Storage Structural Polysaccharides Polysaccharides - Stored for future - To maintain the shape use and integrity of the plant Starch Glycogen CelluloseFound Plants Animals Plants in
  9. 9. starch• Starch is found in food such as rice, potatoes, bread, cereals, noodles, yam, cassava, beans and grains.
  10. 10. DIET PROBLEMSObesity Anorexia
  11. 11. OBESITY• Excess carbohydrates are turned into fats and stored under the skin which will cause someone to be overweight (obese)• This condition increases their risk of heart attack in the future.
  12. 12. Stroke Other complications due to obesity Blood vessel damage (arteriosclerosis) Heart attack Kidney failure
  13. 13. ANOREXIA• Someone who is seriously underweight is called anorexic.• This happen when they don’t eat or eat less than what they need.• They will feel weak and tired all the time because they do not have enough energy.
  14. 14. fats Types of Fats Diet ProblemsSaturated Unsaturated Excessive Deficient Fats FatsAnimals Plants Obesity & Anorexia fats fats Heart attack
  15. 15. fats• Fats give more than twice the energy as the same amount of carbohydrates.• Functions of fats: - reserve supply of energy when we dont eat - are kept under our skin to keep us warm
  16. 16. • Fats are obtained from 2 main sources:(a) Animals - milk, cheese, butter and eggs.(b) Plants - peanut oil, palm oil, olive oil
  17. 17. Are fats bad for us? Not all fats are bad for our health. There are 2 types of fats: (a) Saturated fats - These fats are known for blocking coronary artery in the heart, which eventually leads to heart attack (b) Unsaturated fats - Some fish oils are thought to reduce the growth of fatty deposits in arteries.
  18. 18. Saturated fats Unsaturated fatsFound in Cheese, butter, Vegetable oil, olive animal fats, egg oilEffects blocking coronary reduce the growth artery in the heart, of fatty deposits in which leads to heart arteries. attack.
  19. 19. DIET PROBLEMSObesity & Heart attack Anorexia
  20. 20. HEART ATTACK• Fats can caused someone to be obese.• Some fats can block our blood vessels in the heart and cause heart attack.• The fats can also block the blood vessels in the brain and cause stroke.
  21. 21. Blood clotBlood clot blocks blocks blood flowblood flow Heart Stroke attack
  22. 22. ProteinsConstituent of Diet Problems protein Excessive Deficient Gout Kwashiorkor
  23. 23. Proteins• It consists of long chains of amino acids which are made up of the elements carbon, hydrogen, oxygen and nitrogen.• Like carbohydrates and fats, protein can supply us with energy.• However, their main function is to build body cells, tissues, enzymes & hormones.
  24. 24. • They are essentials for growth and repair of worn- out parts of our bodies.• Muscles, tendons and cartilage in our bodies are made up of proteins.
  25. 25. Proteins can be obtained from meat, eggs, fish, milk, cheese, and beans
  26. 26. DIET PROBLEMSGout Kwashiorkor
  27. 27. GOUT• Proteins are broken down to amino acids.• Excess of amino acids will be turned into uric acids.• These uric acids will accumulate in our joints and cause swelling and pain.
  28. 28. Swollen and Masses ofinflamed joint uric acids Uric acid crystals
  29. 29. Normal Kwashiorkor KWASHIORKOR• This condition affects most of the children from poor countries.• Such children usually have swollen abdomens.• Their skin cracks and becomes scaly.
  30. 30. fibres Importance Diet ProblemsBowel movement Constipation
  31. 31. Fibers• Fiber is made up of cellulose which cannot be broken down by our bodies.• The right amount of fiber in our diet keeps out intestines healthy and working properly.• The lack of fibers in our diet can caused constipation.
  32. 32. • Vegetables, fruits, brown rice, cereals, whole wheat bread are examples of food which are rich in fiber.
  33. 33. Animals such as cows,sheep and goats are called ruminants. They are able to digest cellulose with the help of bacteria in their stomachs, each of which has four chambers
  34. 34. Vitamins Types of Vitamins Diet ProblemsWater-soluble Fat-soluble- Vitamin B - Vitamin A- Vitamin C - Vitamin D - Vitamin E - Vitamin K
  35. 35. vitamins• Vitamins are needed in small amounts by our bodies for health and growth.• Vitamins are classified according to: (a) Water-soluble -Vitamin B and C (b) Fat-soluble - Vitamin A,D,E,K
  36. 36. VITAMIN A
  37. 37. Functions:
  38. 38. Deficiency Problems: Night blindness
  39. 39. Dry and scaly skins
  40. 40. VITAMIN B1
  41. 41. Functions:
  42. 42. DeficiencyProblem:In severe thiamin deficiency, braindamage can occursuch as Korsakoff syndrome and Wernickes disease.
  43. 43. VITAMIN B2
  44. 44. Functions:
  45. 45. Deficiency Problem: Normal amount Anemic amountof red blood cells of red blood cells
  46. 46. VITAMIN B3
  47. 47. Functions:
  48. 48. DeficiencyProblem:
  49. 49. VITAMIN B6
  50. 50. Functions:
  51. 51. DeficiencyProblems:• Confusion• Depression• Irritability
  52. 52. VITAMIN B12
  53. 53. Functions:
  54. 54. Deficiency Problem: Normal amount Anemic amountof red blood cells of red blood cells
  55. 55. VITAMIN C• Sources: - citrus fruits (oranges, lemons), guavas, green vegetables, tomatoes
  56. 56. Functions:
  57. 57. DeficiencyProblems:
  58. 58. VITAMIN D
  59. 59. Functions:
  60. 60. DeficiencyProblems:
  61. 61. Ricket- Abnormal formation of the bones
  62. 62. VITAMIN e
  63. 63. Functions:
  64. 64. VITAMIN K
  65. 65. Function: Promotes clotting of blood
  66. 66. Deficiency Problems:- bruises easily- prolonged bleeding
  67. 67. VITAMINS OVERDOSEVitamin pills are needed for certain groups such as youngchildren, senior citizen and pregnant women. Most of us do not need vitamin supplements because we get all of our vitamins from our diet. It can be poisonous to us!!
  68. 68. DEATH !!! A group of Italian explorers, who had run out of food ate the liver of a polar bear they had shot. Polar bears liver contains an enormous amount of vitamin D and these explorers suffered the effects of vitamin D poisoning, which resulted in several of them dying.
  69. 69. mineralsTypes of minerals Importance Diet Problems - Calcium To maintain - Iron health - Iodine - Sodium
  70. 70. Minerals• Minerals are substances needed by the body in tiny amounts for proper growth and development.• They are needed in some body tissues and are used in some chemical reactions of the body.
  71. 71. CALCIUM• Functions: - building strong bones and teeth - muscles growth and contraction - clotting of blood• Sources: - dairy products, green vegetables and eggs
  72. 72. • Deficiency problems: - rickets
  73. 73. IRON• Functions: - make haemoglobin (the red pigment in red blood cells)• Sources: - liver, meat, green vegetables, eggs
  74. 74. • Deficiency problems: - anaemia (low count of red blood cells)
  75. 75. IODINE• Functions: - make hormones of the thyroid gland• Sources: - seafood, seaweed, green vegetables
  76. 76. • Deficiency problems: - goitre (swelling of the thyroid gland in the lower neck)
  77. 77. SODIUM• Functions: - regulating our body fluids• Sources: - common salt (sodium chloride)• Excessive problem: - high blood pressure
  78. 78. water Importance Factors of intake:- to dissolve things Activity Environment- fills up the cells- helps to cool down
  79. 79. Water• Water plays vital roles in many life processes.• Almost 70% of our bodies are made up of water.• We can survive without food for several weeks but we would die in a few days without water
  80. 80. • Water is needed for: - To dissolve things so they can be carried around our bodies - Fills up the cells so they can maintain their shape - Helps to cool down when you sweat - Acts as transporting agent for digested food, wastes, hormones and antibodies
  81. 81. • The amount of water needed in the body depends on:• (a) The activity of the person• - people who are very active require more• water than those who are less active.
  82. 82. (b) The environmental conditions - people who live in hot conditions need more water than those who are in colder environment.
  83. 83. • Water is lost from body daily during breathing, in the urine, the feces and through sweating.• To balance out the amount of water lost daily, we need to drink about 8 glasses of water a day.
  84. 84. FOOD TESTS
  85. 85. FOOD TESTS CARBOHYDRATES FATS PROTEINSSTARCH SUGARS Emulsion Biurets test testIodine Benedicts test test
  86. 86. IODINE TESTTo test the presence of starch Iodine + starch → blue black (orange) solution NEGATIVE POSITIVE
  87. 87. Benedicts test To test the presence of reducing sugars Benedict’s solution + food (blue) Heated in water bath (5 mins) Positive :Blue → red brick precipitate POSITIVE NEGATIVE
  88. 88. BIURETs testTo test the presence of protein Biuret’s solution + food (clear) Shake well Positive : Clear → purple NEGATIVE POSITIVE
  89. 89. emulsion test To test the presence of fats Ethanol + food (clear) Heated in water bath (5 mins) Positive :Clear → white milky emulsion NEGATIVE POSITIVE
  90. 90. BALANCED DIET Sugar, fats Oils, fats, salts, sweets Proteins, fats Meat, beans, nuts, fish, dairy productsVitamins, fibre, Fruits, minerals vegetables Starch, Rice, bread, fibre cereal, pasta
  91. 91. A Balanced diet A balanced diet contains the right amount of energy,carbohydrates, proteins, fats, fibre, vitamins, minerals and water to meet the requirements of the body
  92. 92. ENERGY REQUIREMENTS• Different individuals need different amounts of energy.• The factors that affect energy requirements are: (a) Age (b) Gender (c) Activities (d) Environment (e) Special needs
  93. 93. AGE GROUPA teenager and an adult need more energy than a child or a baby Children Adults
  94. 94. BODY SIZEA big person needs more energy than a smaller person
  95. 95. GENDER A boy needs more energy than a girl.A male adult needs more energy than a woman.
  96. 96. ACTIVITYAn active person needs more energy than a less active person.
  97. 97. ENVIRONMENTA person from a cold environment needs moreenergy than a person from a warm environment
  98. 98. HEALTHA sick person needs more nutrients than a healthy person
  99. 99. SPECIAL NEEDSA growing child needs plenty of proteins for making new tissues and growth
  100. 100. SPECIAL NEEDS A pregnant lady needs extra proteins, iron and calcium for developing fetus.
  101. 101. SPECIAL NEEDS An athlete needs proteins for building muscles and plenty of simple sugars for instant energy
  102. 102. Digestion
  103. 103. digestion• Digestion is the process of breaking down large food molecules into smaller molecules that can be readily absorb by the body.• Digestion occurs in alimentary canal, starts from the food entering our body through mouth and exit from body through anus.
  104. 104. Human digestive system Mouth Mouth Tongue Pharynx Esophagus Esophagus StomachSmall intestine Liver Stomach Gall bladder PancreasLarge intestine Large intestine Small Anus intestine Rectum Anus
  105. 105. TYPES OF DIGESTION Physical Digestion Chemical Digestion Mechanical breakdown Involves the use ofof food by chewing action enzymes to break of teeth and churning down food substances of the stomach
  106. 106. Enzymes• Enzymes are special types of proteins produced by our body for bringing about and speeding up chemical reactions in the body.• Enzymes that breakdown food substances are called digestive enzymes.
  107. 107. • Different types of digestive enzymes help to break down different nutrients into smaller and soluble molecules• Enzymes have an active site which is compatible to one specific substrate (food) Substrate Products Enzyme Active site
  108. 108. Substrate Products Bonds in the substrate are weakenedActive site Enzyme Enzyme-Substrate Enzyme Each type of Once the Then, the enzyme has a substrate is bound products are specific active to the active site, released & thesite, where only one the bonds in enzyme is ready to type of substrate substrate are bind with another can bind to it. weakened. substrate again.
  109. 109. Process ofDigestion
  110. 110. DIGESTION IN MOUTH• Food is broken down into smaller pieces by the teeth.• Breaking up the food into smaller pieces increases the surface area of the food for the digestive enzymes to act on.• The food is then mixed with saliva, produced in the salivary gland. Salivary gland
  111. 111. • Saliva contains salivary amylase (an enzyme) which catalyses the breakdown of starch into maltose molecules.• However, the food is usually not kept long enough in the mouth for all the starch to be broken down into simple sugar. Amylase Digestion Starch molecule Maltose molecules
  112. 112. • The tongue rolls the partially digested food into small balls called bolus before swallowing.• Then the tongue pushes the bolus toward the pharynx (throat) and into the esophagus
  113. 113. OESOPHAGUS (GULLET)• Oesophagus is a narrow tube with strong muscles in its wall, connecting the mouth and the stomach. Oesophagus• The bolus is pushed along the Stomach esophagus to the stomach by peristalsis.
  114. 114. • Peristalsis is the involuntary wave-like muscular contraction and relaxation in the esophagus. Muscular contractions of• No digestive digestive tract enzymes are (peristalsis) produced here.
  115. 115. DIGESTION IN STOMACH• The stomach have Oesophagus Fundus sphincter muscles to Lower control the flow of esophagael food in and out of sphincter the stomach. Pyloric• Functions of sphincter stomach:– Stores food for 2 to 6 hours– Peristalsis and churning actions break apart the food substances.
  116. 116. • Stomach secretes gastric juices which contains hydrochloric acid and proteases• Functions of hydrochloric acid are : • Stop action of salivary amylase • Provides acidic medium for action of enzymes • Change the inactive form of enzymes into an active form. • Kills most of the microorganism in food
  117. 117. • The gastric enzymes are produced as inactive proteases• Proteases catalyse the breakdown of proteins into polypeptides and peptones. Proteases Proteins Polypeptides
  118. 118. • Mucus in the stomach protects the stomach wall from being destroyed by acid and proteases.• Food is then gradually converted to semi- fluid substance called chyme.• Chyme is pushed into the duodenum.
  119. 119. THE LIVER• The main function of liver in digestion is to produce bile.• Bile is a brownish- Liver green liquid which contains bile salts and bile pigments.• Bile is stored in gall bladder and Bile released into the duct duodenum through bile duct. Gall bladder
  120. 120. PANCREAS• Pancreas produces pancreatic juice which is released Pancreas into the duodenum Pancreatic through pancreatic duct duct.• Pancreatic juice contains enzymes such as: - Lipase Bile duct - Proteases - Amylase Duodenum
  121. 121. DIGESTION IN DUODENUM• The duodenum Bile from Bile from connects the gallbladder liver stomach & the small intestine. Pancreas• It receives bile from the liver Bile and pancreatic duct juice from pancreas. Duodenum
  122. 122. • Functions of bile: - Neutralizes acidic Lipid Bile chyme from stomach salts - Emulsify fats into oil droplets for lipase to act upon Increase surface area
  123. 123.  Functions of pancreatic juice are: - Neutralizes acidic chyme - Contains digestive enzymes: Enzyme Action of the enzymePancreatic Starch  maltose amylaseProteases Proteins  Polypeptide Lipases Fats  fatty acids and glycerol
  124. 124. DIGESTION IN SMALL INTESTINE• The small intestine consists of three sections: DUODENUM connects to the stomach JEJUNUM the longest part ILEUM attaches to the first portion of the large intestine.
  125. 125. • Tiny glands in small intestine produce intestinal juice which contains several types of digestive enzymes: Enzyme Action of the enzyme Maltase Maltose  glucose Protease Polypeptides  amino acids Lipase Fats  fatty acids and glycerol
  126. 126. SMALL INTESTINE VILLI Veins to the liverLayers of Lumenmuscles Blood capillariesVilli Lacteal
  127. 127. ABSORPTION OF DIGESTED FOOD• Absorption is the movement of digested food through the wall of small intestine.• It takes place because of diffusion. Lacteal• Diffusion is the movement of the molecules from higher Blood concentration to lower capillary concentration.• The internal surface of the small intestine is covered with villi.
  128. 128. • The villi increase the surface in contact with the digested food, so it can absorb faster.• The walls of small Lacteal intestine are richly supplied with blood vessels to carry away the Blood digested food. capillary• The fatty acids & glycerol will diffuse into lacteal.• The glucose & amino acids will diffuse into the blood vessels.
  129. 129. LARGE INTESTINE• Large intestine does not secrete any enzyme. Large• Water, minerals and intestine vitamins are absorbed by large intestine.• The undigested and unabsorbed matter are discharged as faeces through anus.
  130. 130. • This process of discarding faeces through anus is called defecation.• If the undigested food passes through the large intestine too slowly, too much of water will be absorbed.• The faeces will become hard and dry.• This condition will leads to constipation.

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