Digestion Flashcards
What dat mouth do
– Food chewed and mixed with saliva
- Breaks down size of food to swallow easier (bolus)
- Increases surface area for enzymes to act on.
(mechanical digestion)
- Saliva helps lubricate food and makes particles adhere
- Saliva is fluid, neutral or slightly acidic, has water, mucus
- Salivary amylase present starch maltose
(chemical digestion)
Oesophagus
muscular tube, carries bolus from mouth to stomach
- Peristalsis
Stomach (6)
– food mixed with gastric juice secreted by glandular stomach lining
- HCl present which kills bacteria and provides optimum pH for pepsin
- Proteins—>peptides
- Renin clots milk
- Temporary store of food until intestine
- Only alcohol can be absorbed in stomach
Pancreas
– produces pancreatic juice with enzymes
- Pancreatic juice passes through pancreatic duct to duodenum
Liver
– produces bile
- Bile is alkaline fluid stored in gall bladder
- Breaks down lipids into smaller pieces by emulsification
(mechanical digestion)
Gall bladder
– stores bile until needed, then releases via bile duct into small intestine
Duodenum
– 1st part of the small intestine
- pancreatic juice active
- Proteins+peptides+amino acids - starch—> maltose
- Fats—->fatty acids + glycerol
- Bile emulsifies fat
Ileum
– digestion completed
- Pancreatic enzymes still active:
Peptides
fats
Maltose
sucrose
Lactose
- Products of digestion are absorbed
- Specially designed for the absorption of food.
- Food material is taken to the hepatic portal vein from capillaries in villus to liver.
how the ileum is adapted for its function
- Ileum is long and presents a large absorbing surface
- Villi (finger-like projections) help increase surface area over which absorption of digested material can take place
- Thin epithelium to allow for easy diffusion
- Dense network of capillaries for absorption of nutrients.
