What does the liver do? - Emma Bryce

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There’s a factory inside you that weighs about 1.4 kilograms and runs for 24 hours a day. It’s your liver: the heaviest organ in your body, which simultaneously acts as a storehouse, a manufacturing hub, and a processing plant. Emma Bryce gives a crash course on the liver and how it helps keep us alive.

Lesson by Emma Bryce, animation by Andrew Zimbelman for The Foreign Correspondents' Club.

There's a factory inside you
that weighs about 1.4 kilograms

and runs for 24 hours a day.

This is your liver,
the heaviest organ in your body,

and one of the most crucial.

This industrious structure
simultaneously acts as a storehouse,

a manufacturing hub,

and a processing plant.

And each of these functions involve
so many important subtasks

that without the liver,
our bodies would simply stop working.

One of the liver's main functions
is to filter the body's blood,

which it receives in regular shipments
from two sources:

the hepatic artery
delivers blood from the heart,

while the hepatic portal vein
brings it from the intestine.

This double delivery
fills the liver with nutrients,

that it then sorts, processes and stores

with the help of thousands
of tiny internal processing plants,

known as lobules.

Both blood flows also deliver the oxygen
that the liver needs to function.

The blood that is received
from the intestine

contains carbohydrates, fats,

and vitamins and other nutrients
dissolved in it

from the food you've consumed.

These must be processed in different ways.

In the case of carbohydrates,

the liver breaks them down
and converts them into sugars

for the body to use as energy
when the filtered blood is sent back out.

Sometimes the body
has leftovers of nutrients

that it doesn't immediately require.

When that happens,
the liver holds some back,

and stacks them in its storage facility.

This facility works like a pantry

for future cases when the body
might be in need of nutrients.

But the blood flowing into the liver
isn't always full of good things.

It also contains toxins
and byproducts that the body can't use.

And the liver monitors these strictly.

When it spots
a useless or toxic substance,

it either converts it into a product
that can't hurt the body

or isolates it and whisks it away,

channeling it through
the kidneys and intestine to be excreted.

Of course, we wouldn't consider
the liver a factory

if it didn't also manufacture things.

This organ makes everything
from various blood plasma proteins

that transport fatty acids
and help form blood clots,

to the cholesterol
that helps the body create hormones.

It also makes vitamin D
and substances that help digestion.

But one of its most vital products
is bile.

Like an eco-friendly treatment plant,

the liver uses cells called hepatocytes

to convert toxic waste products
into this bitter greenish liquid.

As it's produced, bile is funneled
into a small container below the liver,

called the gallbladder,

before being trickled into the intestine

to help break down fats, destroy microbes,
and neutralize extra stomach acid.

Bile also helps carry other toxins
and byproducts from the liver

out of the body.

So as you can see,

the liver is an extremely efficient
industrial site,

performing multiple tasks
that support each other.

But such a complex system
needs to be kept running smoothly

by keeping it healthy

and not overloading it
with more toxins than it can handle.

This is one factory
we simply can't afford to shut down.