nutrition in humans Flashcards
alimentary canal consists of…
mouth oesophagus stomach small intestine large intestine rectum
associated organs are
liver
gall bladder
pancreas
define ingestion
food enters alimentary canal through the mouth
define digestion
digested food enters bloodstream
define egestion
undigested food is removed from the body
define absorption
digested food enters the bloodstream
define assimilation
small food molecules enter body cells for usage
what does bile do
it emulsifies fats
breaks fat up into tiny fat droplets
thus increases surface area to volume ratio of fats and
increase the efficiency of digestion of fats by lipase
what is the function of liver
to produce bile
what is the function of gall bladder
to temporarily store bile be4 releasing it into the duodenum
what is the function of pancreas
produce pancreatic juices which contains digestive enzymes to perform their functions
intestinal juices produces from…
small intestine
what enzyme does intestinal juices contain
maltase
protease
lipase
pancreatic juices produces from…
pancreas
what enzyme does pancreatic juices contain
amylase
protease
lipase
physical and chemical function of mouth
physical: chew and grind into smaller pieces
chemical: produces saliva which contains saliva amylase to digest starch into maltose
physical and chemical function of stomach
physical: churning of food
chemical: produces gastric juices which contain hydrochloric acid and protease to digest proteins into simpler protein molecules/ polypeptide
what does hydrochloric acid in stomach do
to kill harmful microorganisms in food
define duodenum
digesting food
define ileum
aborbing food
what does small intestine contain (in terms of juices)
intestinal juices
pancreatic juices
chemical function of small intestine
amylase digest starch to maltose & maltase digest maltose into glucose
protease digest polypeptides into amino acids
lipase digest lipids into glycerol and fatty acids
why is the breakdown necessary in digestion
so that it is small enough to pass into the bloodstream
what is the function of large intestine
to absorb water and mineral salts
what is the function of rectum
to store faeces
what is the function of the wall of small intestine when the inner surface of small intestine is folded
it increases the surface area to volume ratio and
increase the rate of absorption of nutrients
what is the function of the wall of small intestine when it has villi
it increases the surface area to volume ratio and
increase the rate of absorption of nutrients
what is the function of the wall of small intestine when it is long
it has sufficient time for food to be completely digested and absorbed(by diffusion)
what is the function of the hepatic portal vein
transports absorbed nutrients rich-bood to liver
hepatic portal vein has a higher concentration of…
glucose and amino acids as compared to other parts of the body
what are the 4 functions of the liver
1) bile production
2) deamination of excess amino acids
3) detoxification of alcohol
4) regulation of blood glucose concentration
explain the process of deamination of excess amino acids
it converts excess amino acids into urea to remove from the body
remains of deamination amino acids is converted into glucose
excess glucose is stored as glycogen in the liver
what happens if there is too much glucose in the blood (heavy meal)
pancreas secretes insulin
in the liver, glucose converts into glycogen
thus blood glucose level decreases and goes back to normal
what happens if there is too little glucose in the blood (have not eaten in a period of time)
pancreas secretes insulin
in the liver, glycogen converts into glucose
thus blood glucose level increases and goes back to normal
explain how detoxification of alcohol works
converting harmful subs into harmless ones
explain how regulation of blood glucose concentration works
keeping the amount of glucose in the blood constant
explain the process of emulsification and the adaptations
the emulsification of fats breaks fat up into tiny fat droplets
it increases the surface area to volume ratio of fats and
increase the efficiency of digestion of fats by lipase
