You
have roughly 10,000 tastebuds on your
tongue, which come alive the moment you
put food in your mouth. As nerve endings,
they're responsible for sussing out the
chemicals in the food you've eaten and
transmitting messages to your brain. Without
them you wouldn't be able to experience
salty, bitter, sweet or sour sensations.
While your tastebuds are busy at work,
your teeth grind the food into easily
digestible pieces and your saliva moistens
everything, so it doesn't scrape your
digestive (gastrointestinal) tract on
the way down.
Stomach
Once
you've swallowed your food, it's carried down
the oesophagus to your stomach. Here, your stomach
walls churn the food up to make sure it's mixed
with your acidic digestive juices. By the time
your tummy has finished, the food is a creamy
mixture called chyme (pronounced kime). Once it's
liquefied it can be squirted through a small hole
into your small intestine.
Small
intestine
Did
you know...?
The
average digestive tract is roughly
the length of a double-decker bus.
An
average stool is 75 per cent water.
The remainder is made up of fibre,
dead cells and bacteria.
The
acids in your stomach are so strong,
they kill bacteria and are similar
to those used in industrial metal
cleaner.
This is where
most of the nutrient-digesting action happens.
To help your small intestine cope with the acidity
of the chyme, your pancreas releases an alkaline
and lots of enzymes, which break down the food's
carbohydrates, fat and protein. Meanwhile, your
gall bladder donates some bile to ensure any fat
is melted down thoroughly.
Once the food is reduced to tiny
particles, it's absorbed through the walls of your
small intestine and the nutrients are carried into
your bloodstream.
Large
intestine
Any nutrients
that can't be digested end up here, including
fibre, which has certain components that can't
be absorbed by the human body. Your large intestine
begins at the colon, where some of the remaining
nutrients can be mopped up. After this point,
anything that's left over is waste matter and
is stored in the rectum, waiting for the journey's
end.
