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 metabolism maintenance
• 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 types of breakdown are involved in digestion?

  Physical breakdown and chemical breakdown
• What happens to food when it is placed in the mouth?

  It is physically broken down by chewing
• What role does saliva play in digestion?

  It contains enzymes and moistens food so it can move through the esophagus more easily
• What enzyme is found in saliva?

  Salivary amylase
• What is the function of the esophagus?

  To transport food to the stomach
• What is the stomach primarily composed of?

  A muscular sac
• What are the three important functions of the stomach?

  Mixing food, producing pepsin, and hydrochloric acid
• What does pepsin (digestive enzyme) do?

  Breaks down proteins in the stomach
• What is the role of hydrochloric acid in the stomach?

  Kills bacteria and activates pepsin
• Where does food go after the stomach?

  Into the small intestine
• What happens in the small intestine?

  Most digestion and nutrient absorption occurs
• What organ produces most digestive enzymes?

  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
• Where is bile produced?

  In the liver
• How does bile help with fat digestion?

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

  Efficient nutrient absorption
• What are villi?

  Finger-like projections in the intestine
• How do villi aid in absorption?

  They increase the surface area of the intestine
• Why is a good blood supply important for villi?

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

  It moves into the large intestine
• What does the large intestine do?

  Absorbs excess water and forms feces
• Where is feces stored before removal?

  In the rectum
• What is the order of the digestive process from start to finish?

  1. Food enters the mouth and is chewed.
  2. Saliva is added.
  3. Food travels down the esophagus.
  4. Food enters the stomach.
  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.
• What happens to the nutrients after absorption in the small intestine?

  They enter the bloodstream for use
• What is the purpose of the digestive enzymes produced in the small intestine?

  To aid in the digestion of food
• What is the significance of the pH level in the small intestine?

  It is ideal for digestive enzymes to function
• How does the digestive system ensure efficient nutrient absorption?

  Through adaptations like villi and blood supply
• Where is bile stored?

  Gallbladder