B6.2 - Alimentary Canal

Question 1

what are the different regions of the alimentary canal?

Answer 1

1. Mouth
2. Salivary glands
3. Oesophagus (gullet)
4. Stomach
5. Duodenum
6. Ileum
7. Pancreas
8. Liver
9. Gallbladder
10. Colon
11. Rectum
12. Anus

Question 2

what is the function of the MOUTH?

Answer 2

• ingestion of food
• mechanical digestion by teeth
• chemical digestion of starch by amylase
• formation of a bolus for swallowing

Question 3

what is the function of the SALIVARY GLANDS?

Answer 3

• saliva contains amylase for chemical digestion of starch in food
• liquid to lubricate food and make small pieces stick together

Question 4

what is the function of the OESOPHAGUS (GULLET)?

Answer 4

• transfers food from the mouth to the stomach, by peristalsis

Question 5

what is the function of the STOMACH?

Answer 5

• produces gastric juice containing pepsin, for chemical digestion of protein
• also hydrochloric acid to kill bacteria
• peristalsis churns food up into a liquid

Question 6

what is the function of the DUODENUM?

Answer 6

• first part of the small intestine
• receives pancreatic juice for chemical digestion of proteins, fats and starch as well as neutralising the acid from the stomach
• receives bile to emulsify fats (a form of physical digestion)

Question 7

what is the function of the ILLEUM?

Answer 7

• second part of the small intestine
• enzymes in the epithelial lining carry out chemical digestion of maltose and peptides
• very long and has villi to increase surface area for absorption of digested food molecules

Question 8

what is the function of the PANCREAS?

Answer 8

• secretes pancreatic juice into the duodenum via pancreatic duct for chemical digestion of proteins, fats and starch

Question 9

what is the function of the LIVER?

Answer 9

• makes bile, containing salts to emulsify fats (physical digestion)
• assimilation of digested food such as glucose
• deamination of excess amino acids

Question 10

what is the function of the GALL BLADDER?

Answer 10

• stores bile, made in the liver, to be secreted into the duodenum via the bile duct

Question 11

what is the function of the COLON?

Answer 11

• first part of the large intestine
• absorption of water from undigested food
• absorption of bile salts to pass back to the liver

Question 12

what is the function of the RECTUM?

Answer 12

• second part of the large intestine

- stores faeces

Question 13

what is the function of the ANUS?

Answer 13

• egestion of faeces

Question 14

what is the definition of INGESTION?

Answer 14

Is the taking in of substances, e.g. food and drink, into

the body through the mouth

Question 15

what is the definition of DIGESTION?

Answer 15

Is the breakdown of large, insoluble food molecules into small, water- soluble molecules using mechanical and chemical processes

Question 16

what is the definition of MECHANICAL DIGESTION?

Answer 16

is the breakdown of food into smaller pieces without chemical change to the food molecules

Question 17

what is the definition of CHEMICAL DIGESTION?

Answer 17

is the breakdown of large, insoluble molecules into small, soluble molecules

Question 18

what is the definition of ABSORPTION?

Answer 18

is the movement of digested food molecules through the wall of the intestine into the blood

Question 19

what is the definition of ASSIMILATION?

Answer 19

Is the movement of digested food molecules into the cells of the body where they are used, becoming part of the cells

Question 20

what is the definition of EGESTION?

Answer 20

Is the passing out of food that has not been digested, as faeces, through the anus