nutrition in humans Flashcards
order of processes in nutrition
ingestion - digestion - absorption ( assimilation; what happens after nutrition) - egestion
human digestive system produce
chemicals to make digestion faster
human digestive system consists of
gut or alimentary canal, organs (liver, gall bladder and pancreas
processes in mouth (ingestion and digestion)
teeth break food into smaller pieces, increasing surface area of food so that enzyme digest it more efficiently (chem reaction, enzyme is salicaary amylase). salivary glands that secretes saliva
process of oesophagus (no sign of digestion)
push food into stomach, longitudinal muscles outer wall and circular muscles inner wall, food is pushed forward, longitudinal muscles contract, the circular muscles relax, widens the lumen for food to enter
processes in stomach
gastric glands secrete gastric juice
processes in small intestine
walls of si contains glands that secrete digestive enzymes, enzymes from pancreas, food is digested
duodenum (in si) purpose
largely involved in digestion, is connected to liver and pancreas, digestive juices from liver and pancreas are released at duodenum
purpose of illeum
focus on absorption
large intestine has
colon and rectum. faeces are stored in the rectum. main function of the colon is to absorb water and mineral salts
organs and glands associated with the gut (liver and gall bladder) ( food does not pass these organs)
attached to liver are 3 blood vessels, hepatic portal vein, hepatic vein and hepatic artery, liver cells produce and secrete bile, containing bile salts, does not contain enzyme but aids in digestion of fats, bile is stored temporarily in gall bladder, bile flows into duodenum via bile duct
hepatic artery
blood flows to the liver and away from heart, oxygenated blood. blood high iin glucose during meal and low when fasting
