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We spend a lot of time talking lately
about eating, digesting and metabolizing food.
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And those are some of my favorite things about
the world! It was a great moment.
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But like any good party or brunch buffet,
In the end, we were left with a mess.
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And I'm not talking about spilled beer and
Dorito Crumbs, I'm talking toxic levels.
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Garbage that must be disposed of first
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In your body comes a lot of the cleaning that comes
after the metabolism is controlled by the liver, the
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plays a tremendous role in managing dead cells and
leftover chemicals in the digestive and urinary systems.
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But your liver can't actually transport waste.
of your person
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Your lungs can help and exhale carbon.
carbon dioxide and of course your colon will run out
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useless poo and parts of old cells.
But much of its chemical waste still needs
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classified and eliminated, that is, a system
steps to clean the bats.
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And this is your urinary system.
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This system, and especially your kidneys
-- makes all kinds of important homeostatics
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things like regulating the flow of water,
ionic salt concentrations and pH and
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Affecting your production of red blood cells
and blood pressure.
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But its main objective: what we do
focus on the next two lessons
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-- so it filters out toxic waste
Your blood - like the nitrogenous waste created
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metabolizing proteins and transporting them
of the body
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And, spoiler alert! – all this includes
how and why and what of your urine.
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By now, you probably already know that the kidneys are filters.
and you can think of them as filters straining
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take the bad and leave it at that
a hairball at the bottom of the bathtub.
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But this is just the opposite.
what to think
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Most of what's in your blood is whole
removed from the kidneys. then your body pulls
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go back to what you want to hold on to first
The remainder is sent on a one-way trip to the bubble.
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It goes something like this: you don't empty your fridge
just taking out the rotten fruit and the fluffy leftovers.
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Instead, you have to let it all out.
and put it on the counter and then fix it
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what goes back in the fridge and what goes
In the trash.
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This is How You Clean Your Urinary System
high. And it does its job very well.
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So this morning I opted for the healthy one.
route and instead of eating my normal breakfast
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You're welcome, I had a large 32oz protein shake.
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My digestive system was working and everything
the protein has been hydrolyzed into amino acids,
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taken and sent by my blood
anywhere in my body to build and repair cells.
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It's a beautiful thing, but not without it.
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How nutrients are metabolized, especially
Protein: Makes a mess.
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You must remember that amino acids are unique,
that have nitrogen in their amino groups.
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And since we cannot store amino acids,
Extras are processed into storable carbs or fat.
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But the amino group is not used in these
storage molecules, thus becoming
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NH3 or ammonia which turns out to be toxic. Then the
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The liver converts ammonia into a less toxic compound,
Urea that our kidneys filter out in our urine.
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Once out of the body, urea can be broken down again.
to ammonia, therefore dirty, urine soaked
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Toilets and litter boxes smell like ammonia.
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Now this removing the nitrogen
Littering is one of the urinary system's biggest jobs.
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Its other main function is to regulate balance.
Salt and water in your blood and both
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these tasks are processed as a whole
tubular system which is your urinary system.
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So let's take a look at some basic steps for peeing.
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His kidneys are a pair of dark red, the size of a fist,
bean-shaped organs sitting on each side
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Your spine against the posterior body wall.
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The kidneys are retroperitoneal, which means that
lie between the dorsal wall and the peritoneum
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- the membrane that surrounds the abdomen
cavity - instead of inside the cavity itself,
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as well as your intestines and your stomach.
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Each kidney initially has three distinct layers
with the outermost shell.
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Below is the marrow,
a series of conical masses
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Tissues that secrete urine in small, sac-like tubes.
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And finally, the innermost layer is the kidney.
Basin, a funnel-shaped tube surrounded by
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smooth muscle that moves urine peristaltically
from the kidney, to the ureter and to the bladder.
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Because the main function of the kidneys is to filter
Continuous blood, end up seeing a lot.
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In fact, they stop at one point.
20 percent of your total blood volume.
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Oxygenated blood enters the kidneys through the kidneys.
the great renal arteries supplying nearly
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a quarter of all blood is pumped through the
heart every minute This means that your kidneys
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filters about 120 to 140 liters of blood EACH
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When they enter the kidneys, many renal arteries branch off,
many times and ends up in tons of little strands of hair.
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So a cardioid is not just a great filter; instead,
Each consists of about a million curves.
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microscopic filtering units called nephrons.
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Structurally and functionally they are nephrons.
where is the real blood processing business
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-- which, like "pee" -- starts in three steps:
filtration, absorption and secretion.
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Each nephron consists of a round corpuscle
which is at the top of the crust, followed by
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a long, tortuous renal tubule that winds
between the cortex and the medulla.
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The outer part of the corpuscle is cup-shaped.
Feature called glomerular capsule because
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It contains a whole tangle of capillaries.
Called the glomerulus - which comes from the
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Latin word for "ball of wool", meaning
about how it looks.
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And the endothelium of these capillaries is
very porous. So you allow a lot of liquid,
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Residues, ions, glucose and amino acids
pass from the blood to the capsule, but
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They block larger molecules like blood.
Cells and proteins to keep them in the blood.
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and exit via the peritubular capillaries
also known as vasa recta.
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Well all those things that get squeezed
the blood in the glomerulus is called filtrate,
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which is then shipped at great cost
three-centimeter-long twisted renal tubule.
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Even though it looks like it's just a tube
It has three main parts, some of which are
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Permeable to certain substances, not others.
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First along is the proximal convoluted tubule,
or PCT, which sounds so complicated
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As the name implies; then the hose falls
on a spectacular sharp turn called the Nephron
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Loop or loop of Henle, I call it something
I personally like it better - and finally
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ends in the distal convoluted tubule or DCT,
terminating in a collecting channel.
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All this twisting can make the tubule look
like super inefficient but it actually works
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an important purpose, as expected.
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Like the small intestine, the
long, curly shape of the nephron
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more time and space to pick it all up again
Useful things you can.
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And the parts also make this winding road possible
of the tubules, which are at the end, to
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affect running processes
closer to the start when they intersect.
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Because a lot of what ends up in it
tube are valuable products such as
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Ions and glucose and water - and we don't
I just want to pee on you all if we can help it.
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So let's go through the whole process starting with this.
above, with the proximal convoluted tubule or PCT.
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The walls here consist of cubical epithelium.
cells, with large ancient mitochondria that make
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ATP to drive pumps that extract a large amount of sodium
Active transport filtrate ions.
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These cells are also covered by microvilli.
that increase and help your surface
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reabsorb most of the good things from
filter and return to the blood.
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The remaining filtrate passes through the PCT
in the loop of Henle, which begins at the
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cortex, then emerges in the medulla
go back to the crust.
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And the shape of that loop is the key to its function,
because its main function is to promote the reabsorption
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of water creating a concentration of salt
Gradient in marrow tissue.
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This is mainly done by active pumping.
You exit on the ascending branch. This creates
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some very salty interstitial fluid in the
Medulla, that is, when new filtration descends.
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Descent loop in front, passive water
it flows out and into supersalty space.
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Since most of the water is absorbed by the
The blood quite fast, the salinity of the
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Space is not diluted.
So that you can continue to draw water from the next
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Load filtering on the downstream branch.
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Needless to say, this is very important.
Because when we pee all the water
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got into our kidneys, we would die of dehydration
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But even after that, we're still
two-thirds of the process.
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If we leave the loop of Henle, in
The convoluted tubule distal and beyond the
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The collection channel is the remaining filtrate.
now officially pisses. but there's one more
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Component that we should squeeze more
before we get rid of things. Urea.
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Even if we consider urea as a waste
-- just one more serving of this protein shake
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that has to be removed - actually the kidneys
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They use it to increase the concentration gradient.
earlier in the process of making the marrow
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even more salty by the filtering that returns
passes through the ascending branch.
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So, in the final steps, after filtering
exits the DCT, enters the collection channel,
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that goes back to the medulla. Meanwhile
salt passively extracts even more water
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from the collecting duct, some passive urea
urine comes out too.
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Make the marrow even more salty and,
in turn more effective in extracting water
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a few steps behind the ascending branch.
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So essentially there's a group of travelers
of urea that escapes from the urine finds its
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I walk back to the Henle Loop, and then
Of course, it all goes back to collecting
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Conduit: an ammonia-smelling circuit called urea.
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Now all that's left is some kind of final call
selectively smuggle more junk -- like
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Hydrogen, potassium, and certain organic acids
and bases - using active transport.
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This is called a tubular secretion and is transported
Select only waste types that already exist
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found their way to the blood that's in
peritubular capillaries, ready to leave the kidneys.
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This step is something like emptying your pockets
of the last crumpled handkerchiefs or receipts
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while walking a garbage bag to go
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And this is how your kidneys clean
Chaos left over from the big party
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They metabolize food. So if this is what you thought
Your kidneys were fine mesh
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bad things leaked? now you know what it is
is not true.
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If you thought your urinary system was basically
is: water goes in, piss comes out?
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This is DEFINITELY not true.
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And if you thought we were done talking about it
your urine, this is also not true,
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because next time we will learn
how your body regulates what you eat
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and what is excreted, and we will find out
can happen if this fix goes wrong.
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But now you've learned the anatomy of yourself.
Urinary system and how your kidneys filter
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Metabolic waste and salt and water balance.
blood concentrations. Special
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You learned how nephrons use glomerular filtration,
tubular reabsorption and tubular secretion
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to replenish water and nutrients
the blood and make urine with the remains.
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Many thanks to our manager Linnea
Boyev, and thanks to all our Patreons.
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Sponsors whose monthly contributions help contribute
Intensive course possible, not just for you,
9:36 - 9:39
but for everyone If you like the crash course
and you want to help us keep making videos like
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this you can go to patreon.com/crashcourse.
9:42 - 9:45
This episode was filmed at Doctor Cheryl
C. Kinney Crash Course Studio, was written
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by Kathleen Yale, edited by Blake de Pastino,
and our consultant is Dr. brandon jackson
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Directed and edited by Nicole Sweeney;
our sound designer is Michael Aranda, and
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The graphics team is Thought Cafe.