digestive system

• What is the primary function of the digestive system?

  To break down food into tiny pieces for absorption
• What are the three main groups of nutrients that humans need?

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

  It breaks down large molecules in food for absorption
• What is the role of saliva in digestion?

  It helps make the food mixture more liquid and contains salivary amylase
• What happens to food after it is swallowed?

  It passes down the esophagus to the stomach
• What are the three important functions of the stomach?

  Mixing food, producing pepsin, and producing hydrochloric acid
• What is pepsin and what does it do?

  Pepsin is a protease enzyme that breaks down proteins
• How does hydrochloric acid assist in digestion?

  It kills bacteria and provides the right environment for pepsin
• What is the primary function of the small intestine?

  To absorb digested food into the bloodstream
• What organ produces most of the digestive enzymes?

  The pancreas
• What is the role of bile in digestion?

  It neutralizes stomach acid and emulsifies fats
• Where is bile produced and stored?

  Bile is produced in the liver and stored in the gallbladder
• How does the structure of the small intestine aid in absorption?

  It has villi that increase surface area and a good blood supply
• What are villi?

  Finger-like projections that increase the surface area of the small intestine
• Why is a good blood supply important for the villi?

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

  Excess water is absorbed, leaving behind feces
• What is the final storage location for feces before elimination?

  The rectum
• What is the sequence of the digestive process from start to finish?

  1. Food is chewed in the mouth with saliva added
  2. Food travels down the esophagus to the stomach
  3. Food is mixed in the stomach and pushed into the small intestine
  4. Pancreatic juices and bile are added in the small intestine
  5. Nutrients are absorbed into the bloodstream
  6. Undigested material moves to the large intestine for water absorption
  7. Feces are stored in the rectum until elimination
• How do the roles of the pancreas and gallbladder differ in digestion?

  The pancreas produces digestive enzymes, while the gallbladder stores and releases bile
• What is the significance of the pH level in the small intestine?

  A neutral pH is ideal for digestive enzymes to function effectively
• What happens to the food after it has been digested in the small intestine?

  It is absorbed into the bloodstream
• Why is it important for the lining of the small intestine to have a single layer of surface cells?

  It allows nutrients to diffuse a very short distance
• How does the digestive system ensure that nutrients are efficiently absorbed?

  Through adaptations like villi, a good blood supply, and a short diffusion distance