digestive system

• What do bile salts such as sodium hydrogen carbonate do?

  They emulsify fats and help neutralize acid from the stomach.
• What is an omnivore?

  An animal that eats both meat and plants.
• What does the term heterotrophic mean?

  An organism that cannot make its own food.
• What is meant by a balanced diet?

  Eating the correct amounts of each food type.
• What are two glands in the alimentary canal and their products?

  • Liver: secretes bile
  • Salivary glands: secrete amylase
  • Pancreas: secretes pancreatic juice
• Name two parts of the small intestine.

  Duodenum and ileum.
• Name two parts of the large intestine.

  Colon and caecum.
• What is symbiosis?

  Where two organisms of different species live close to one another where at least one benefits.
• Give an example of symbiosis in the human digestive system.

  Bacteria in the large intestine that produce vitamins.
• What are two advantages of symbiosis to humans?

  Produce vitamins and provide competition against pathogenic bacteria.
• What is lipase and where is it secreted?

  It is an enzyme that acts on lipids, secreted by the pancreas.
• What is the pH of the site of action for lipase?

  It acts in the duodenum, where the pH is neutral.
• What is the human dental formula for an adult?

  2 I 2 C 1 PM 2 M 3 = 32 teeth.
• What is the difference between the teeth of carnivores and herbivores?

  Carnivores have more or longer canines, while herbivores have less canines and more molars for crushing plants.
• What are two functions of the large intestine?

  To make vitamins B & K and to reabsorb water.
• What are the names of structures X, Y, and Z in the digestive system?

  X = Villus, Y = Lacteal, Z = Intestine.
• What process results from the contraction of muscle tissue in the intestine?

  Peristalsis.
• What type of muscle makes up the digestive system organs?

  Smooth muscle.
• Where in the human alimentary canal is most water reabsorbed?

  In the colon/large intestine.
• What is digestion?

  The breakdown of food into smaller soluble particles.
• Why is digestion necessary?

  To make the food particles soluble for transport in blood.
• Distinguish between mechanical and chemical digestion.

  Mechanical is the physical breakdown of food, while chemical is the breakdown using enzymes.
• State three functions of the liver.

  To store glycogen, produce bile, and detoxify the body.
• What is one digestive function of the pancreas?

  To produce enzymes (lipase and amylase) and secrete sodium hydrogen carbonate to neutralize stomach acid.
• Where do both the pancreas and liver secrete their products?

  Into the duodenum.
• Where is bile stored?

  In the gall bladder.
• Describe the relationship between the liver, small intestine, and the hepatic portal vein.

  • The liver produces bile and processes nutrients.
  • The small intestine absorbs nutrients.
  • The hepatic portal vein carries nutrients from the small intestine to the liver.
• Where is the liver located in relation to the stomach?

  Above the stomach in the upper abdomen.
• Where is amylase produced in the human alimentary canal?

  In the salivary glands and pancreas.
• What is the function of HCl in the stomach?

  To kill microorganisms and lower the pH to activate pepsinogen into pepsin.
• What does pepsin do?

  It acts on proteins to form peptides.
• What process is involved in the passage of the products of digestion into the blood?

  Diffusion.
• How is the ileum adapted for the absorption of nutrients?

  It has a large surface area, is one cell thick, and has microvilli present.
• What food is mostly absorbed by the lacteal?

  Fats.
• Where do the fats absorbed by the lacteal travel to?

  To the lymphatic system.
• What is peristalsis and where does it occur?

  It is the alternate contraction of muscles, occurring in the esophagus and small intestines.
• Why is a low pH important in the stomach?

  To denature enzymes in microorganisms and activate pepsinogen.
• What is nutrition?

  • The process by which an organism obtains and uses its food.
  • Involves digestion and absorption of nutrients.
• What are the two types of digestion?

  • Mechanical digestion: Physical breakdown of food.
  • Chemical digestion: Breakdown of food using enzymes.
• What are the functions of the stomach?

  • Physical digestion: Churning of food.
  • Chemical digestion: Hydrochloric acid, pepsinogen, and mucous.