in december 2019 the chinese authorities notified the world that a virus was spreding their communities
in the following months, it spread to other countries, with cases doubling within days.
This virus is Severe Acute Respiratory Syndrome-Realated Coronavirus 2 that causes the
disease called Covid-19 and that everyone simply calls coronavirus.
Corona may spread via surfaces, but it still uncertain how long it can survive on them.
its main way of spreading seems to be droplet infection when peaple cough, or if you
touch someone who's ill then your face, say rubbing your eyes or nose.
the virus starts its journey here, and then hitches a ride as a stowaway deeper into the body
its destinations are the interstines, the spleen or the lungs, where it can have the
most dramatic effect.
Even just a few corona viruses can cause quite a dramatic situation.
The lungs are lined with billions of epithelial cells.These are yhe border cells of your
body, lining your organs and mucosa waiting to be infected.
Corona connects to a specific receptor on its victim's membranes to inject its genetic material.
The cell, ignorant of what's heppening, executes the new instructions, which are pretty
simple: copy and reassemble It fills up with more and more copies of the original virus
until it reaches a critical point and receives one final order, self-destruct.
The cell sort of melts away, releasing new corona particles ready to attack more cells.
The number of infected cells grows exponentially.
After about 10 days, millions of body cSells are infected , and billions of viruses swarmed the lungs.
The virus has not caused too much damage yet, but corona is now going to release
a real beast on you, your own immune system. The immune system, while there to protect
you, can actually be pretty dangerous to yourself and needs tight regulation. And as
immune cells pour into the lungs to fight the virus, Corona infects some of them
and creates confusion. Cells have neither ears nor eyes, they communicate mostly
via protein called cytokines. Nearly every important immune reaction is controlled by them.
Corona causes infected cells to overreact and yell bloody murder.
In a sense, it puts the immune system into a fighting frenzy and sends way more soldiers than it should, wasting
its resources and causing damage. Two kinds of cells in particular wreak havoc.
First, neutrophils, which are great at killing stuff, including our cells. As they arrive
in their thousands, they start pumping out enzymes that destroy as many friends as enemies.
The other important type of cells that go into a frenzy are killer T-cells, which usually
order infected cells to commit controlled suicide. Confused as they are, they start ordering
healthy cells to kill themselves too. The more and more immune cells arrive, the more
damage they do, and more healthy lung tissue they kill. This might get so bas that it can
cause permanent irreversible damage, that leads to life long disabilities.
In most cases, the immune system slowly regains control it killsthe infected cells, intercepts the viruses
trying to infect new ones and cleans up the battelfield. Recovery beginns. The majority
of peaple infected by Corona will get through it with relatively mild symptoms. But many
cases become severe or even critical. We dont know the percentage because not all cases
have been identified, but its safe to say that there is a lot more than with the flu.
In more severe cases, Millions of epithelial cells have died and with them, the lungs' protective
lining is gone. That means that the Alveoli tiny air sacs via which breathing occurs
can be infected by bacteria that aren't usually a big problem. Patients get pneumonia.
Respiration becomes hard or even fails, and patients need ventilators to survive.
The immune system has fought at full capacity for weeks and made millions of antiviral
weapons. And as thousands of bacteria rapidly multiply, it is overwhelmed. They enter
the blood and overrun the body, if this happens, death is very likely.
The Corona virus is often compared to the flu, but actually, it's much more dangerous.