Nutrition - Digestive System Flashcards
Mouth & pharynx function
Chewing (mastication) mechanical breakdown
Produces saliva which contains enzyme salivary amylase which begins breakdown of carbs, moistens food protects against teeth decay
Food is swallowed & passed from mouth into pharynx
Oesophagus
Involuntary muscular contractions (peristalsis) push food into stomach
Stomach
Produces gastric juices containing hydrochloric acid which kills bacteria and pepsin to break down protein
Pancreas
Secretes pancreatic juices containing digestive enzymes to help further digestion and absorption of nutrients
Lipase - breaks down fat
Amylase - Breaks down carbs into glucose
Trypsin - Breaks down protein into amino acids
Liver
Produces bile acids which enables fats to mix with water (emulsification)
Gallbladder
Storage of bile which is released into small intestine
Small Intestine
Receives bile from gallbladder and pancreatic juices
Primary site for digestion and absorption
Villi and microvilli provide large surface area for absorption
Digested food is able to pass into blood vessels in the wall of the intestine through the process of diffusion
Large Intestine
Absorbs water, vitamins & minerals
Contains bacteria which produce vitamins and help prevent infection in the intestine
Rectum
Stores Faeces
Anus
Opening for elimination of waste
Mastication
Process of teeth grinding food down in the mouth
Peristalsis
Pushing food from oesophagus to stomach
Saliva
Moistens the food and helps prevent tooth decay
Salivary Gland
Produces saliva
Salivary Amylase
Digestive enzyme in saliva that begins to breakdown carbs/starch
Bolus
Ball of chewed food ready for swallowing
Chyme
Acidic fluid which passes from stomach to small intestine consisting of gastric juices and partly digested food
Bile
Fluid produced in the liver helps aid digestion
Emulsification
Process of fats mixing with water, bile acids allow for this to happen
Pancreas
Secretes pancreatic juices like insulin and glucagon (its endocrine function)
Produces enzymes to digest food
3 parts of small intestine
Duodenum, Jejuneum & ileum
Villi
Tiny finger like projections that increase surface area within small intestine for absorption, on each villi is thousands of microvilli
what is chemical digestion
Breakdown of food by enzymes
End product of starch
Maltose
End product of Polypeptides
Amino acids
End product of Triglycerides
Glycerol and fatty acids
End product of Sucrose/lactose/maltose
Glucose
Enzyme and nutrient for mouth release
Salivary amylase and carbs
Enzyme and nutrient for stomach release
Pepsin and proteins
Enzyme and nutrient for release from pancreas into small intestine 1
Lipase and fats
Enzyme and nutrient for release from pancreas into small intestine 2
Trypsin and proteins
Enzyme and nutrient for release from pancreas into small intestine 3
Amylase and carbs
Chemical digestion area 1
Mouth produces salivary amylase which breaks down carbs (starch) this then creates maltose
Chemical digestion area 2
Stomach breaks down protein with pepsin which then produces polypeptides. Stomach can also absorb water, glucose vitamins and alcohol
Chemical digestion area 3
Within the duodenum pancreatic juices and bile are secreted, the bile then emulsifies the fats and breaks them down. The small intestine contains particular structures called microvilli
Inner lining of small intestine
Has many folds called Plicae, on the plicae are thousands of finger like protrusions called villi
On each villus are thousands of hair like protrusions called microvilli/brush borders
These structures increase the surface area for greater absorption and digestion
