Chp 28 Digestion Flashcards
Digestion
Break down of large food molecules into smaller, soluble ones
Mechanical digestion
Physical breakdown of food into smaller pieces
Chemical digestion
Breakdown of food into smaller molecules by enzymes, stomach acid or bile
Steps of human digestion
Ingestion
Digestion
Absorption
Egestion
Mouth : Physical
Reduce food into smaller pieces increasing surface area for enzymes to work on
Food is turned into bolus
Teeth formula
2I 1C 2PM 3M
Incisor
Cutting + bitting
Canine
Gripping + tearing
Premolar + molars
Grinding + Crushing
Mouth : Chemical
Salivary amylase
Consists of water, salt, mucin, amylase and lysozyme
Oesophagus
Pushes food down into stomach
Peristalsis
Rhythmic contraction and relaxation of muscles
Stomach
Entrance : Cardiac sphincter muscle
Exit : Pyloric sphincter muscle
Muscular
Expandable
J-Shaped bag
Gastric gland
Produces gastric hormones which causes production of gastric juice
HCl in stomach
Converts pepsinogen into pepsin
Kills microorganism
Loosen fibrous food
Deactivates salivary amylase