Name: Just How Fast Does A Virus Spread?
Uploaded: 2018-08-17T06:20:20.000Z
Duration: 4 min 19 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

Viruses are one of the earliest forms of life as we know it.

They're little strings of genetic material (called RNA) coated in a protein jacket.

They've evolved to make people sick in very specific ways.

They hijack cells and use the cells to produce more viruses.

Once the virus is ready, can force its host to share it with others.

For example, the varicella-zoster virus (VZV) causes little red spots to appear all over

ITCHY, and the virus did that on purpose!

It fills the pox with more viruses, so when people scratch them, they let the virus out

of their body, spreading it to people nearby.

And this is how lots of viruses move through the population.

They get inside a body, and after a few days -- or, sometimes, years -- they'll try and

The time from when they get inside a person to when they try and spread, is called the

During that time, the virus is invading cells, and fighting the immune system.

During the incubation period, if you have a virus, you might not even notice!

Chickenpox can take weeks before the first pox appear!

The flu, another common virus, is less patient.

Its incubation period is only half of a day.

It really wants to get out into the world again.

The flu spreads so fast through your friends because it can spread so fast in your body

The influenza virus evolved to make you cough and sneeze, so it can hitch a ride on the

tiny droplets of water that come out when you do so!

Let's say Ian has the flu and coughs, then Autumn inhales a few droplets (even way later

Once inside her body, influenza virus hopes to hit an epithelial cell.

Epithelial cells line the airway and are the perfect place for a new flu virus to set up

Once it finds the right cell, it has to get inside, but cells don't just let anyone off

So, to convince the cell to let it in, viruses have little bumps on the outside of their

Receptors are like keys, and if the virus has the right key, our cell will surround

This can happen less than 10 minutes after a flu droplet is inhaled!

Once inside the cell, the influenza takes off its jacket -- it transforms.

From there, the little bit of genetic RNA material heads to nucleus of the cell, and

It steals a "cap" from the host cell's RNA molecules and puts it on itself.

Once it's wearing the cap, the flu virus can trick the DNA in the nucleus to make more

As more and more virus fills up the cytoplasm, the new guys steal bits of the cell's outer

membrane to put on a jacket and head out into the body.

Even though the influenza virus invades human cells really quickly, it can take a day or

The immune system is on the prowl looking for infected cells and any virus in your bloodstream.

If you have a fever, or feel sore and achy, that's a side-effect of your immune system

Fevers change the body's temperature to try and slow the virus down.

The achyness comes from our own body try helping the immune cells trying to fight the infection.

After a few days, the immune system usually wins out, but chances are you've already spread

Which means you've won the battle, but lost the war.

In the end, viruses aren't trying to hurt us, they're just fighting to survive.

They can be annoying, dangerous and even deadly, but learning about how they work has taught

us a lot about ourselves, and  the history of life on our planet.

This video was written by our good friend Trace Dominguez.

He's got a YouTube channel where he looks at how the world works through the lens of

Check out his latest series here where he explores the how the television business got

Make sure you come back every Monday for a brand new video.

As always, I'm Blocko and this has been Life Noggin.