LO3 Digestive System Flashcards
what are the three main food groups?
carbohydrates
fats
proteins
what do enzymes do?
speed up reactions —> catalysts
what are minerals?
elements found in the ground
function of buccal cavity
to chew, chop and chern.
mixes food with saliva.
function of salivary glands
to produce saliva, that contains enzymes
function of epiglottis
prevents food going down the trachea
function of oesophagus
transports food to your stomach
function of stomach
contains hydrochloric acid and mucus, which contains enzymes
function of small intestine
a long tube lined with villi.
absorption of nutrients —> carbs, fats, proteins
function of liver
produces bile
stores nutrients
process of assimilation
function of pancreas
produces pancreatic juice —> cocktail of enzymes
function of gallbladder
stores bile
function of bile duct
delivers bile into small intestine
function of pancreatic juice
delivers pancreatic juice into small intestine
function of large intestine
absorbs water
function of rectum
stores faeces
function of anus
gets rid of faeces
mechanical digestion -
chemical digestion -
Digestive enzymes
substrate = carbohydrate
enzyme = amylase
substrate = protein
enzyme = pepsin
substrate = fats
enzyme = lipase
outline the enzyme action in chemical digestion
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
describe the process of absorption
-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
describe the process of assimilation
-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
description & psychological cause
IBS
muscles of large intestine (colon) have abnormal rhythms
symptoms of IBS
-abdominal pain
-constipation and diarrhoea
-bloated feeling
-indigestion
-flatulence
dietary triggers of IBS
-alcohol
-fizzy drinks
-fried food and processed food
-can be brought out by stress
treatment of IBS
-a good diary alongside notes on symptoms
-use fresh ingredients
-regular exercise
-try to relax / reduce stress
description & psychological fair
-crystals form in gallbladder due to imbalance of bile
-high levels of cholesterol result in crystal formation ranging up to pebble size
symptoms of gallstones
-discomfort (particularly after a meal with fat in it) as the bile duct is blocked
-fever, nausea & jaundice
risk factors of gallstones
-alcohol
-obesity
-being female
-being over 40
-having liver damage, IBS or a family history of gallstones
treatment of gallstones
-avoid high amounts of fat in meals
-lithotripsy and surgery to remove gallstone.
description and psychological cause of coeliac disease
-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
symptoms of coeliac disease
-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
