digestive system

• What is the main function of the digestive system?

  To break down food for absorption
• Why do humans need to eat food?

  For energy and to maintain metabolism
• What are the three main groups of nutrients?

  Carbohydrates, proteins, and fats
• Why is digestion necessary for nutrient absorption?

  It breaks food into tiny absorbable pieces
• What two types of breakdown are involved in digestion?

  Physical breakdown and chemical breakdown
• What is the role of saliva in digestion?

  To make food more liquid and aid breakdown
• What enzyme is found in saliva?

  Salivary amylase
• What is the esophagus also known as?

  The gullet
• What are the three important functions of the stomach?

  Mixing food, producing pepsin, and hydrochloric acid
• What type of enzyme is pepsin?

  A protease enzyme
• What is the role of hydrochloric acid in the stomach?

  Kills bacteria and aids pepsin function
• What happens to food after it leaves the stomach?

  It enters the small intestine
• What is the primary function of the small intestine?

  To absorb digested food into the bloodstream
• Where are most digestive enzymes produced?

  In the pancreas
• What does the gallbladder release into the small intestine?

  Bile
• What are the two main roles of bile?

  Neutralizes stomach acid and emulsifies fats
• What is the pH nature of bile?

  Alkaline
• How does bile aid in fat digestion?

  By emulsifying fats into tiny droplets
• How is the lining of the small intestine adapted for absorption?

  It has villi that increase surface area
• What are villi?

  Finger-like projections in the small intestine
• Why is a good blood supply important for villi?

  It maintains the concentration gradient for absorption
• What happens to undigested material in the large intestine?

  Excess water is absorbed, leaving feces
• Where is feces stored before removal?

  In the rectum
• What is the order of the digestive process?

  1. Food enters the mouth and is chewed.
  2. Saliva is added from salivary glands.
  3. Food travels down the esophagus to the stomach.
  4. Stomach mixes food and adds enzymes and acid.
  5. Food moves to the small intestine with pancreatic juices and bile.
  6. Nutrients are absorbed into the bloodstream.
  7. Undigested material moves to the large intestine.
  8. Water is absorbed, leaving feces in the rectum.