Digestion Flashcards
Nutrients
Any substance required for the body for its metabolism
Nutrients include..
Carbohydrates, lipids, protiens, vitamins, minerals
Carbohydrates
Sugars and Starches
Monosaccharides
Single sugar Molecules
Disaccharides
Two linked sugar molecules
POlysaccharides
Many Linked sugar molecules
Monosaccharide sugars
Glucose, fructose, galactose, ribose
Disaccharide sugars
Sucrose, maltose, lactose
Polysaccharide Sugars
Starch, Glycogen
Rich in starch..
Bread, pastry, pasta, rice
Rich in Sugar
Cake, biscuits, lollies
Protiens def
Building blocks of Amino acids joined by peptide bonds
Complete Protiens
Animal Protiens, meat, eggs
Incomplete protiens
Plant Protiens, grains, legumes
Protien Rich food
Dairy foods, eggs, lean meats, soy milk beans
Lipids
Fats and Oils
Monoglyceride
Glycerol + 1 FA
Diglyceride
Glycerol + 2 FA
Triglycerides
Glycerol + 3 FA
Low density Lipids
Carry cholesterol from liver to tissues
High density Lipids
Collect cholesterol from tisses to bring back to liver
Lipid Rich foods
Dairy food, pastry, fried foods, oily fish, avos.
Vitamins
Water or fat soluable. 13 known vitamins
Vitamin B & C
Water soluable - easily excreted
Vitamin A, D, E , K
Fat soluable - abosrbed from gut
Dietary minerals
Inorganic substances required by living organisms for their metabolism
Macrominerals substances
Na, Mg, K, Ca, Fe, P, S, Cl - required in large amounds
Trace Minerals
Cu, Cr- required in small amounts
Chemical Digestion in mouth
Enzyme=Salivary amalayse, product = polysaccharides
Main functions of saliva
lubricates mouth, dissolves food, holds food together, rinses teeth, destroys bacteria, contains salivary amalayse.
Mechanical Digestion in mouth
Action of teeth chewing - mastication
Types of teeth & function
Incisors for biting, canines for tearing, pemolars and molars for crushing and grinding
Dental Formula
2123/2123
Swallowing
Bolus is pushed towards pharynx. Passes down oesophagus into stomach
Peristalsis
Wave like motion caused by contraction/relaxation of curcular muscles
Structure of alimentary tube
4 layers - mucosa, submucosa, muscle layer, serosa
Stomach entry and exit
Cardiac sphincter prevents backflow. Pyloric sphicter separates stomach from duodenum
Mechanical digestion in stomach
Has oblique muscle layer to contract in variety of ways. - creats churning
Gastric pits
Gastric juice secreted by gastric glands found in gastric pits
HCL and bateria
HCL creats acid environment for enzyme pepsin to work & also kills bacteria entering stomach
Large intestine
1.5 metres long that secretes mucous. Water absorption occurs
Faeces
Semi-solid material made up of undigested food material, bacteria, bile pigments, discarded lining cells and water
Defaecation
Elimination of undigested wastes from large inestine
Cellulouse
Insoluable polysaccharide - Fibre. Stimulates regular peristalsis
Bowel Disease
Constipation leads to development of haemorrhoids
Diarrhoea
Frequent elimination of watery faeces. Caused by food of bacteria/viruses.
Bowel Cancer
A colostomy provides alternative route if sections are removed
Obese
Weight is more than 20% above than reconmended/ bmi is greater than 30
BMI formula
kg/m2