alimentary canal

Question 1

what are the 10 regions of the alimentary canal?

Answer 1

the mouth, oesophagus, stomach, liver, gall bladder, pancreas, small intestine, large intestine, rectum and anus

Question 2

Function of mouth?

Answer 2

chewing turns the food into smaller pieces and increases the SA:VOL ratio, making it easier for enzymes to break down the food molecules. Amylase from saliva breaks down starch into maltose. The chewed food is then swallowed and passes into the oesophagus.

Question 3

Function of Oesophagus?

Answer 3

Peristalsis pushes food into the stomach.

Question 4

Function of Stomach?

Answer 4

Muscular contractions breaks down food. Stomach acid (protease) destroys bacteria. Partially digested food is released in small amounts into the small intestine.

Question 5

Function of liver?

Answer 5

produces bile

Question 6

Function of gall bladder?

Answer 6

stores bile

Question 7

Function of pancreas?

Answer 7

Makes the enzymes maltase, lipase and protease.

Question 8

Function of small intestine?

Answer 8

The lining of the small intestine is covered by villi which absorb the products of digestion into the bloodstream.

Question 9

how does bile help with digestion?

Answer 9

bile emulsifies fats, turning them into tiny droplets, with a large SA:VOL ratio. Bile neutralises the stomach acid, providing the optimum PH for action of the enzymes in the small intestine.

Question 10

Function of large intestine?

Answer 10

water is removed into blood.

Question 11

Function of rectum?

Answer 11

where faeces are stored

Question 12

Function of anus?

Answer 12

egestion occurs here.

Question 13

Adaptations of villi:

Answer 13

• Large surface area which increases the rate of diffusion.
• Contains a dense network of blood capillaries for the absorption of amino acids and glucose and maintains a steep diffusion gradient.
• Contins latéral for the absorption of fatty acids, glycerol and tiny fat droplets.