Digestive System

• Nutrition


  help living organisms develop their bodies, grow, heal damaged body parts, and give energy for life and activity.
• Modes of Nutrition


  1. Autotrophic
  2. Heterotrophic
• Autotrophic Nutrition


  can produce their own food
• Heterotrophic Nutrition


  cannot produce their food
• Autotroph 


  organism that produces its own food: plants, algae, some bacteria, phytoplankton
• Heterotroph


  organism that does not make its own food: animals, fungi, most basteria, most protozoa
• Digestion


  the mechanical and chemical process by which complex food substances are broken down into simpler substances
• Mechanical Digestion


  This process breakdown food physically by teeth and tongue. It begins from mouth and tongue to stomach. Its parts are teeth, tongue, muscles. Its function are chewing and grinding. And it facilitates chemical digestion.
• Chemical Digestion


  This process breakdown food by using enzymes so that easily absorbed by cells. It begins when food is mixed with saliva in mouth. It starts in mouth and till intestine by using intestinal juices. Its materials are enzymes, bile, juices, and acids. Chemical digestion facilitates the absorption of nutrients.
• Parts of Digestive System

  1. Mouth
  2. Esophagus
  3. Stomach
  4. Liver
  5. Gall Bladder
  6. Pancreas
  7. Small Intestine
  8. Large Intestine
  9. Anus
• Mouth


  produces saliva where mechanical mastication of food takes place to form bolus
• Bolus


  the food that gets chewed and mixed up with saliva
• Esophagus


  a muscular tube that conducts peristalsis and serves as passageway for food
• Peristalsis


  involuntary wave-like contractions of the muscles in the digestive tract
• Stomach


  a muscular sac that contains gastric juices that helps to break down the food chemically
• Liver


  produces bile that helps in the digestion of fats
• Gall Bladder


  helps in the storage of bile and discharging it from the cystic duct
• Pancreas


  releases pancreatic juices and enzymes which help in the digestion of protein and starch
• Small Intestine


  a tube that contains villi which absorbs nutrients and water coming from the food
• Large Intestine


  a tube that absorbs water and salts from the material that has not been digested as food, and gets rid of any waste products
• Anus


  an opening that eliminates feces inside the body
• Digestive Processes


  1. Ingestion
  2. Digestion
  3. Absorption
  4. Elimination
• Ingestion


  taking in of food materials
• Digestion


  breaking down of food into smaller pieces
• Absorption


  movement of nutrients, water, and electrolytes from the small intestine into the cell, then into the blood
• Elimination


  undigested material passes out the system
• Feeding Mechanism of Animals

  1. substrate-feeders
  2. filter-feeders
  3. fluid-feeders
  4. bulk-feeders
• substrate-feeders


  animals live on the source of their food and eat through it
• filter-feeders


  aquatic animals strain the food particles from the water
• fluid-feeders


  animals suck fluid containing nutrients from another animals
• bulk-feeders


  animals break down and swallow large amount of food
• Animal Nutrition


  1. Required Nutrients

  • Carbohydrates
  • Fats
  • Proteins
• Essential Nutrients


  • Amino Acids
  • Fatty Acids
  • Vitamins
  • Minerals
• Plant Nutrition


  Photosynthesis
• Photosynthesis


  the process by which light energy is converted into chemical energy in order for the plant to make their own food
• Plant Parts involved in Photosynthesis


  1. Roots
  2. Leaves
• Roots


  absorbs and transports water and nutrients from the soil to the rest of the plant
• Leaves


  • the part of the plant where photosynthesis takes place.
  • Chloroplast contain chlorophyll that traps sunlight
  • Exchange of oxygen and carbon dioxide happends inside the stomata.
• Photosynthesis


  1. The root absorb the water and nutrients and bring it to the other parts of the plant.
  2. Carbon Dioxide enters the stomata and chlorophyll in the leaves traps sunlight and oxygen is given off into the air.
  3. Sugar is converted into starch.
  4. Starch is stored as food in the plant.

  A) Photosynthesis
• Feeding Mechanism of Carnivorous Plants


  Trapping Mechanism - insect-eating plants capture and digest their prey through pitfalls and traps.