LO3 Digestive System

Question 1

what are the three main food groups?

Answer 1

carbohydrates
fats
proteins

Question 2

what do enzymes do?

Answer 2

speed up reactions —> catalysts

Question 3

what are minerals?

Answer 3

elements found in the ground

Question 4

function of buccal cavity

Answer 4

to chew, chop and chern.
mixes food with saliva.

Question 5

function of salivary glands

Answer 5

to produce saliva, that contains enzymes

Question 6

function of epiglottis

Answer 6

prevents food going down the trachea

Question 7

function of oesophagus

Answer 7

transports food to your stomach

Question 8

function of stomach

Answer 8

contains hydrochloric acid and mucus, which contains enzymes

Question 9

function of small intestine

Answer 9

a long tube lined with villi.
absorption of nutrients —> carbs, fats, proteins

Question 10

function of liver

Answer 10

produces bile
stores nutrients
process of assimilation

Question 11

function of pancreas

Answer 11

produces pancreatic juice —> cocktail of enzymes

Question 12

function of gallbladder

Answer 12

stores bile

Question 13

function of bile duct

Answer 13

delivers bile into small intestine

Question 14

function of pancreatic juice

Answer 14

delivers pancreatic juice into small intestine

Question 15

function of large intestine

Answer 15

absorbs water

Question 16

function of rectum

Answer 16

stores faeces

Question 17

function of anus

Answer 17

gets rid of faeces

Question 18

mechanical digestion -

Question 19

chemical digestion -

Question 20

Digestive enzymes

Answer 20

substrate = carbohydrate
enzyme = amylase

substrate = protein
enzyme = pepsin

substrate = fats
enzyme = lipase

Question 21

outline the enzyme action in chemical digestion

Answer 21

mouth:
chemical digestion starts —> salivary amylase —> starch to maltose

stomach:
amylase —> stops working as pH is high due to hydrochloric acid
hydrochloric acid activates pepsin —> breaks down proteins into polypeptides

gall bladder:
bile from liver stored in gall bladder —> breaks fats into tiny globules (emulsification)

pancreas:
pancreas (and walls of small intestine) —> supply enzymes
trypsin (proteins) lipase (fats) and carbohydrase (sugars)

small intestine:
chyme too acidic —> neutralised by alkalines —> enzymes break up nutrients —> fats into fatty acids and glycerol, proteins into amino acids and complex sugars into glucose
—> bulk of nutrients ready for absorption through villi

large intestine:
water and salts are removed from waste

Question 22

describe the process of absorption

Answer 22

-this process happens in the small intestine
-villi increase surface area for maximum nutrient absorption
-each villi contains blood capillaries and a lymphatic capillary called a lacteal
-sugars, amino acids, minerals and water- soluble vitamins diffuse into the blood capillary.
-fatty and acids and glycerol recombine as fats as they pass into the lymphatic lacteal along with fat-soluble vitamins

Question 23

describe the process of assimilation

Answer 23

-this process happens in the liver
-once in the blood nutrients are not immediately pumped around the body
-hepatic portal vein carries them to liver
-this is the process where the liver acts as a huge storage and distribution centre
-fats, fat-soluble vitamins and minerals such as iron are stored
-the liver distributes nutrients as required
-the process of sorting, utilising and distribution.
- necessary metabolic chemicals is called assimilation

Question 24

description & psychological cause
IBS

Answer 24

muscles of large intestine (colon) have abnormal rhythms

Question 25

symptoms of IBS

Answer 25

-abdominal pain -constipation and diarrhoea -bloated feeling -indigestion -flatulence

Question 26

dietary triggers of IBS

Answer 26

-alcohol -fizzy drinks -fried food and processed food -can be brought out by stress

Question 27

treatment of IBS

Answer 27

-a good diary alongside notes on symptoms -use fresh ingredients -regular exercise -try to relax / reduce stress

Question 28

description & psychological fair

Answer 28

-crystals form in gallbladder due to imbalance of bile -high levels of cholesterol result in crystal formation ranging up to pebble size

Question 29

symptoms of gallstones

Answer 29

-discomfort (particularly after a meal with fat in it) as the bile duct is blocked -fever, nausea & jaundice

Question 30

risk factors of gallstones

Answer 30

-alcohol -obesity -being female -being over 40 -having liver damage, IBS or a family history of gallstones

Question 31

treatment of gallstones

Answer 31

-avoid high amounts of fat in meals -lithotripsy and surgery to remove gallstone.

Question 32

description and psychological cause of coeliac disease

Answer 32

-wheat protein called gluten triggers our immune system to mistake our body tissue as being harmful and attacks it -villi in the ileum (small intestine) wall are flattened and destroyed. -Inflammation drives absorption of nutrients

Question 33

symptoms of coeliac disease

Answer 33

-abdominal pain -bloating -flatulence -secondary conditions could be anaemia (low iron) and osteoporosis (weak bones) -diarrhoea and weight loss due to poor absorption of nutrients