science quiz

• Ingestion


  The process of taking in food, drink, medicine and other substances through the mouth
• Digestion


  The mechanical and chemical breakdown of food into small organic fragments
• Mechanical digestion


  • The physical breakdown of large pieces of food into smaller pieces which can subsequently be accessed by digestive enzymes
• Chemical digestion


  • Enzymes break down food into the small molecules the body can use
• Absorption


  The simple products of digestion are small enough to be absorbed by the epithelial cells of the intestinal villi
• Wearing a face mask and face shield during COVID-19 pandemic are required to protect oneself and prevent the spread of viruses and other microorganisms to other people
• Ingestion

  1. Under normal condition, we use our hands to put something like food, drink, medicine and other substances in our mouth

  2. There are cases where droplets and viruses may enter our body through our mouth

  3. Wearing a face mask and face shield during COVID 19 pandemic are required to prevent the spread of viruses and other microorganisms to other people
• Digestion

  1. Mechanical digestion refers to the physical breakdown of large pieces of food into smaller pieces

  2. Chemical digestion, enzymes break down food into the small molecules the body can use
• Absorption


  The simple product of digestion is small enough to be absorbed by the epithelial cells of the intestinal villi
• Assimilation


  1. The movement of digested food molecules into the cells of the body where they are used

  2. The liver is important in assimilation

  3. Glucose is used in respiration to provide energy

  4. Amino acids are used to build new proteins
• Egestion


  1. Chyme passes from the ileum into the large intestine, it is essentially indigestible food residue (mainly plant fibers like cellulose), some water, and millions of bacteria

  2. The colon absorbs most of the remaining water, leaving semi-solid waste material called feces

  3. Feces are stored in the rectum, the last part of the large intestine

  4. Egestion happens when these feces pass out of the body through the anus
• Digestive Enzymes

  • Organic catalysts that initiate or speed up chemical reactions
  • They work well in temperature ranging from 30°C -40°C
  • Raw diets such as vegetable salads, fruits, nuts, vegetables and fruit juices are rich with enzymes that hasten the chemical breakdown of food
• Digestive Enzymes

  • Carbohydrase (breaks down carbohydrates into simple sugars)
  • Protease or peptidase (breaks down proteins into amino acids)
  • Lipase (breaks down lipids or fats into fatty acids and glycerol)
  • Nuclease (breaks down nucleic acids into nucleotides)
• My diet includes raw foods like vegetable salads, fruits, nuts and fruit juices
• I drink 10 glasses of water per day
• I do a light exercise after eating like walking
• My family provided a regular serving of vegetables and fruits
• Digestion


  The process of breaking down food molecules into simpler and more soluble forms that can be absorbed by the body
• Life processes of digestion

  • Ingestion (putting food in the mouth)
  • Digestion (break down of food molecules into simple and soluble form)
  • Absorption (digested food are absorbed by the villi of small intestine)
  • Assimilation (simple products are used to build up bigger molecules of proteins, carbohydrates)
  • Egestion (undigested food are moved out of the body)

  
• Food fuels the body for the needed energy and to maintain its basic life processes
• The human digestive system is tube-like because it has an opening where food enters the mouth and the waste products exit through an anus

  
• Organs of digestion

  • Organs of alimentary tract
  • Accessory organs

  
• Digestion in the mouth

  1. Food is broken down into small pieces by 32 teeth

  2. Tongue mixes food with saliva

  3. Salivary glands secrete ptyalin that start the chemical digestion of carbohydrates

  4. Partially digested food forms into a ball-shaped bolus

  5. Swallowing pushes the bolus into the pharynx
• Pharynx


  1. 6 inches long, during swallowing, the sphincter muscles relax and raise the epiglottis to cover the opening of trachea so food passes from the pharynx to the esophagus then into the stomach by wavelike contraction and relaxation of involuntary muscles called peristalsis
• Digestion


  The process of breaking down food molecules into simple and soluble form
• Stomach

  • Pear-shaped organ, about 30.5cm long and 15.2 cm wide and has the capacity of about 1 liter
  • Has many folds called rugae
  • Contains gastric glands secreting gastric juices and hydrochloric acid that digest proteins
  • Contraction or churning of the stomach mixes the food with gastric juices and the food is converted into chyme, a semifluid partially digested food
  • Food usually remains in the stomach for 2-3 hours
• Pyloric valve


  At the intestinal end of the stomach, opens and closes several times emptying or moving the chyme to the small intestine
• Small intestine is about 6 meters long
• Digestion process

  1. Ingestion

  2. Digestion

  3. Absorption

  4. Assimilation

  5. Excretion
• Digestive system


  • Tube-like with an opening where food enters the mouth and waste products exit through an anus
  • Divided into organs of alimentary tract and accessory organs

  
• Pharynx


  1. 6 inches long, during swallowing, the sphincter muscles relax and raises the epiglottis to cover the opening of trachea so food passes from the pharynx to the esophagus
• Swallowing

  1. Sphincter muscles relax

  2. Epiglottis raises

  3. Food passes from pharynx to esophagus
• Organs of digestion

  • Mouth
  • Pharynx
  • Esophagus
  • Stomach
  • Small intestine
  • Large intestine
  • Accessory organs (salivary glands, liver, gallbladder, pancreas)

  
• Mouth/Oral cavity


  Contains 32 teeth to break down food, tongue to mix food with saliva, ducts of salivary glands that secrete ptyalin to start chemical digestion of carbohydrates
• Stomach


  Pear-shaped organ, about 30.5cm long and 15.2 cm wide, capacity of about 1 liter, has many folds called rugae
• Pharynx


  1. 6 inches long, sphincter muscles relax and epiglottis raises to cover trachea opening so food passes from pharynx to esophagus
• Esophagus


  Food moves through by peristalsis (wavelike contraction and relaxation of involuntary muscles)
• Digestion in stomach

  1. Gastric glands secrete gastric juices and hydrochloric acid

  2. Contraction/churning mixes food with gastric juices

  3. Food converted into chyme (semifluid partially digested food)

  4. Sphincter muscles on both sides closed during churning

  5. Food remains in stomach for 2-3 hours
• Pyloric valve


  At intestinal end, opens and closes several times to empty or move chyme to small intestine
• Small intestine


  About 6 meters long and 2.5 cm in diameter, divided into duodenum, jejunum, and ileum, organ of complete digestion, walls contain folds lined with villi and microvilli for absorption