Curiosity Is A Door To New Dicoveries

Sunday, May 2, 2010

Parts of the digestive system

Buccal cavity

the teeth grind the food into smaller substances, so as to increase the surface area for salivary amylase to work on.
Te tongue will then roll the food into a bolus so that it can travel down the oesophagus more easily.
Starch is broken down into maltose.

Oesophagus

peristalsis will occur
series of wave-like contractions of muscular walls-circular and longitudinal muscles
improved by exercising regularly
constipation can be prevented when peristalsis is consistent and roughage or fibre is consumed.

Stomach

muscular, elastic bag,with thick, well-developed stomach wall
pH 2
churns food into liquid chyle
secretes pepsin and hydrochloric acid
pepsin is a protease that works well in pH 2-acidic condition
hydrochloric acid- provides acidic condition for pepsin to work well/kills foreign particles,like germs and bacteria
protein is broken down into polypeptides/peptones(shorter chains of proteins) then into amino acids

Duodenum

all classes of food is digested- carbohydrates, fats, proteins
pancreas produce pancreatic juice containing enzymes(maltase,lipase,pancreatic amylase,trypsin), and sends it to the small intestine via the pancreatic duct
Emulsification: breaking down of fats into tiny fatty droplets, to increase surface area for lipase to work on, with the help of the bile
fats are digested into fatty acids and glycerol by lipase
proteins are digested by trypsin into amino acids
starch is digested into maltose by the pancreatic amylase
maltose is digested by maltase into glucose

Jejunum

Ileum

Large intestine

the beauty exposed ;