MAIN FUNCTIONS

·        Digest and absorb ingested nutrients

·        Excrete waste products of digestion

TYPES OF DIGESTION

·        MECHANICAL → Physical breakdown of food into smaller pieces – AKA Chewing

·        CHEMICAL → Chemical breakdown of food by enzymes found in saliva & pancreas

UPPER GI TRACT FUNCTIONS

·        Mouth / Oral cavity – Ingests and breaks down food

·        Pharynx & Oesophagus                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            - Carries food from mouth to stomach

·        Stomach

o    Storage site until passed to small intestine

o    Food mixes with gastric acid to form chyme (paste)

o    Absorbs fat-soluble minerals

LOWER GI TRACT FUNCTIONS

·        Small intestine

o    Digests contents from stomach

o    Absorption of water & electrolytes

·        Large intestine

o    Absorption of water & electrolytes

o    Storage & elimination of waste

·        Anus – excretion of waste

ACCESSORY DIGESTIVE ORGANS

·        Liver

o    Metabolism of fats, proteins & carbs

o    Detoxifcation

o    Regulates blood sugar levels

o    Regulates blood clotting

·        Pancreas

o    Secretes glucagon and insulin

o    Secretes enzymes to break down foods

§  Lipase → digests fats

§  Amylase → digests carbs

§  Protease → digests protein

·        Gall Bladder

o    Stores bile produced by the liver

o    Bile

§  Digests fatty foods

§  Absorbs fat soluble vitamins

§  Carries waste out of the liver

DIGESTION PROCESS

·        INGESTION

o    Act of ingesting or consuming something orally

o    AKA Eating

·        PROPULSION

o    Movement of food along the digestive tract through peristalsis

o    Involuntary contractions that move food through digestive tract

·        DIGESTION

o    Mechanical Process - Physically breaking down food substances into smaller particles

o    Chemical Process - Food molecules broken down with enzymes

·        ABSORPTION

o    Products of digestion are absorbed by the blood to be supplied to rest of body

·        DEFECATION

o    Elimination of undigested material from the body