Anatomy and Physiology of Animals/The Gut and Digestion/Test Yourself Answers

1. Name the four different kinds of teeth
 * The four different kinds of teeth are incisors, canines, premolars and molars.

2. Give 2 facts about how the teeth of cats and dogs are adapted for a carnivorous diet
 * The teeth of cats and dogs are adapted for a carnivorous diet with small chisel shaped incisors for biting off flesh, sharp canines for holding and killing prey and carnassials for shearing flesh.

3. What does saliva do to the food?
 * Saliva lubricates food for swallowing and contains an enzyme for breaking down starch.

4. What is peristalsis?
 * Peristalsis is the waves of smooth muscle contraction that pass down the gut and move the food along.

5. What happens to the food in the stomach?
 * In the stomach food is churned and mixed and gastric juice that contains enzymes to digest proteins is added. Hydrochloric acid to make the stomach contents acidic for the protein digesting enzymes is also added here.

6. What is chyme?
 * Chyme is the liquefied and partially digested food that passes down the gut.

7. Where does the chyme go after leaving the stomach?
 * The chyme enters the small intestine after leaving the stomach.

8. What are villi and what do they do?
 * Villi are the small finger-like projections from the wall of the small intestine that increase the surface area for the absorption into the blood of the digested nutrients.

9. What happens in the small intestine?
 * In the small intestine food is digested and resulting nutrients are absorbed into the blood via the villi.

10. Where is the pancreas and what does it do?
 * The pancreas is situated in the first bend of the duodenum after it leaves the stomach. It produces pancreatic juice that contains enzymes for digesting carbohydrates, fats and proteins.

11. How does the caecum of rabbits differ from that of cats?
 * In rabbits the caecum is enlarged to form a functional caecum that contains microorganisms for breaking down the cellulose walls of plants. Note that because of the position of the functional caecum at the end of the gut animals like the rabbit eat their faeces to take advantage of the digested nutrients.

12. How does the liver help control the glucose levels in the blood?
 * The liver helps control the glucose levels in the blood by converting the glucose to glycogen that it stores. This is then released when blood glucose levels are low. The hormone insulin produced by the pancreas controls this process.

13. Give 2 other functions of the liver
 * Other functions of the liver include the detoxification of toxic substances like alcohol, storing iron and production of bile, proteins, vitamin A and heat.