human nutrition 1

• Nutrients essential for humans


  • Carbohydrates
  • Fats and oils
  • Proteins
  • Vitamin C
  • Vitamin D
  • Mineral ions (e.g. calcium, iron)
  • Fiber
  • Water
• Carbohydrates


  Provide energy for respiration in cells
• Carbohydrates


  • Rice
  • Pasta
  • Potatoes
• Fats


  • Used as long-term stores of energy
  • Provide insulation under the skin
• Fats


  • Cheese
  • Fatty meats
  • Butter
• Proteins


  Vital for growth and repair of tissues
• Protein-rich foods


  • Fish
  • Meat
  • Eggs
• Vitamin C


  • Maintains healthy skin and gums
  • Deficiency causes scurvy
• Vitamin D


  • Helps body absorb calcium
  • Deficiency leads to rickets
• Mineral ions (e.g. calcium, iron)


  Essential for human nutrition
• Calcium


  • Needed for strong bones and teeth
  • Plays a role in blood clotting
• Calcium-rich foods


  • Milk
  • Cheese
  • Eggs
• Iron


  Needed to make hemoglobin in red blood cells to carry oxygen
• Iron-rich foods


  • Red meat
  • Spinach
• Fiber/Roughage


  Helps food move through stomach and intestines
• Fiber-rich foods


  • Vegetables
  • Fruits
  • Whole grains
• Water


  Needed for chemical reactions in cells
• Parts of the digestive system


  • Mouth
  • Esophagus
  • Stomach
  • Small intestine
  • Large intestine
  • Rectum
  • Anus
• Associated organs of the digestive system


  • Salivary glands
  • Pancreas
  • Liver
  • Gallbladder
• Parts of the small and large intestines


  • Duodenum (first part of small intestine)
  • Ilium (second part of small intestine)
  • Colon (larger part of large intestine)
  • Rectum
  • Anus
• Functions of the digestive system


  • Ingestion (taking in substances like food and drink)
  • Digestion (breakdown of food)
  • Absorption (movement of nutrients into blood)
  • Assimilation (uptake and use of nutrients by cells)
  • Ejection (removal of undigested food as feces)
• Types of digestion


  • Physical digestion (breakdown without chemical change)
  • Chemical digestion (breakdown with chemical change)
• Physical digestion


  • Breakdown of food into smaller pieces without chemical change
  • Increases surface area for action of enzymes in chemical digestion
• Organs involved in physical digestion


  • Teeth
  • Stomach
  • Bile in duodenum
• Physical digestion in the stomach

  • Stomach walls squeeze food to liquefy it
  • Stomach lining contains muscles that contract to physically squeeze and mix food with digestive juices
• Role of bile


  • Produced by the liver and stored in the gallbladder
  • Released into the duodenum (first part of small intestine)
  • Helps neutralize stomach acid
  • Emulsifies large fat droplets into smaller ones to increase surface area for chemical digestion