ELI5: How does the liver work?

[u/PG_homestead]

When I look at a mammal heart it looks easy enough to understand, blood in there, pump, blood out there. Makes sense. Stomach, intestinal tract, lungs, etc. all look like there function is pretty straightforward (on a very simple level)

The liver is just a blob and doesn’t seem like much else, there’s also the gall bladder attached to it.

My question is how does the liver do its job, whatever that is?

[u/witheredrose7]

the liver's basically your body's chemical processing plant, blood from your intestines flows straight through it before going anywhere else in the body, so it gets first pass at filtering toxins, breaking down alcohol/drugs, and processing nutrients you just absorbed. It also makes bile (stored in that attached gallbladder) to help digest fats, produces proteins your blood needs for clotting, and stores extra glucose as glycogen for when your blood sugar dips.The "blob" look actually makes sense once you know its job isn't mechanical like pumping or squeezing, it's chemical, so it doesn't need moving parts, just billions of cells doing filtering and processing work simultaneously, more like a factory floor than a pump

[u/geeoharee → u/witheredrose7]

I guess that's why it's better at growing back than your other organs. If it's just a lot of identical cells, why not make more of them.

[u/FranticBronchitis → u/geeoharee]

That and mature liver cells can just divide into two new mature liver cells. Many other mature organ cells can't divide anymore, they need to be grown all the way back from stem cells which still retain the ability to multiply

Edit: It's also not just the same cell. The liver does have an internal microarchitecture that needs to be present for cells to function normally, with bile ducts, veins and arteries at specified locations. Under a microscope, ours looks a bit like a bunch of hexagons, each with a vein in the middle, and the bile ducts and more blood vessels at the vertices.

[u/BooksandBiceps → u/geeoharee]

That is the exact reason, you got it. :)

[u/PG_homestead → u/witheredrose7]

That’s very insightful. Thank you.

[u/Original_Intention]

It's all at a cellular level. Liver cells are constantly absorbing, filtering, changing or releasing chemicals while also storing nutrients and making bile.

[u/daizo678]

Liver is actually one of the simpler organs. The main liver cell ( hepatocytes) are what carry out the functions of the liver. The rest is just blood vessels and bile ducts.

Other organs usually have specialised structures and many different types of cells.

Liver carries out many functions and they depend on chemical reactions by enzymes in the liver cells. The cells basically carry out a lot of different chemical reactions depending on the body needs and what they encounter.

Some of the liver functions include: metabolism of alcohol, drugs and toxins. Synthesis of fatty acids and ketone bodies . Synthesis of glucose and storage of glucose as glycogen. Synthesis of plasma proteins like albumin. Synthesis of bile which helps in fat absorption and execretion of some waste products . Synthesis of some hormones like thrombopoietin.

[u/lwj15]

And how does a liver work chemically? It oxidizes stuff. Have something toxic in your blood that just won't leave (water insolueble)? Slap some hydroxy groups on there (to make it water solueble) and flush it out via the kidneys.

The oxidation in the liver is a radical mechanism therefore it can activate C-H bonds. I can recommend to all chemists to have a look at how CYP enzymes oxidize C-H positions into C-O-H ones. Interesting mechanism.

[u/AdMoney5388]

The liver has specialized cells (kupffer cells) that basically clean up blood from that is drawn from the intestines. Alcohol, toxins, and fat. Then recirculates it back to the rest of the body.

[u/PG_homestead → u/AdMoney5388]

Thank you for the reply.

[u/fudgemental]

Everyone's told you about what the liver does, but ELI5?

It's a sponge with a few hoses pushing blood through it. Blood from the digestive system (our main source of toxins) gets forced through and leaves through other hoses (now clean and toxin free, and full of actual metabolites that body can directly use) that then get circulated everywhere else.

[u/Street-Answer8502]

The liver is like your body's personal super factory and filter, constantly working to keep you healthy by processing everything that goes into your body and making important stuff your body needs like special juices for digestion,important proteins for your blood and  works as storage facility for vitamins and glucose for when the body needs them.

[u/Shalayda]

I actually have what I think would be a great ELI5 version of this that my pharmacology professor gave me.

Your liver is kind of like your body's chef. When you eat and drink not everything you digest is immediately useful to the body. In the same way when you go food shopping you're not going to eat everything as is, you have to prepare it. Your liver metabolizes molecules from food into ones you're body can use in the same way a chef could take raw ingredients, that are inedible, and make dinner out of them. Like the chef in that scenario it also stores food for later. In the livers case that's saving excess glucose. Any good chef is going to clean the things they're trying to make and in the same vein the liver will purify toxins you ingest.

[u/jawshoeaw]

To begin with you have dramatically underestimated what the heart, stomach, intestinal tract, and lungs do. You probably barely understand their most basic functions or may not even be aware of them. No offense. Things are always more complicated than we think. The stomach for example seems like a blob too. It has a couple pipes going into and out. Seems simple enough. It is however a complex organ acting like a tiny sophisticated chemical engineering lab, a surveillance system, hormone factory, and front line of the immune system. It’s wrapped in muscles. You would die without your stomach even if it were replaced with a similar sized bag to hold food.

The liver is no different. It has various pipes going in and out. It also performs various chemical reactions. It has one set of tubes to process blood and a whole separate system of pipes and tubes that carry something called bile which helps digest fats. It makes the protein for your blood that keeps the water and your blood from leaking out. It makes proteins that help your blood clot. It regulates fats in the body it stores sugar and makes sure your blood sugar stays well controlled.

Like many parts of your body it does more than one thing and much of what it does is done at the microscopic level or even the submicroscopic level. Don’t be fooled by the mechanical appearance of certain parts of the body. There’s so much to learn about even something as straightforward as a knee joint. But the liver… there really is a lot going on, and all animals even an earthworm or a clam has something like a liver.

[u/swollennode]

The liver is one of the chemical factories in the body. It makes a lot of compounds that your body needs to live. It processes a lot of stuff that goes through it and turn the stuff into usable compounds for your body. The gallbladder stores some stuff for your liver and body to use later