Description:
The new coronavirus packs a devastating punch. It penetrates deep into
your lungs,causing our immune cells to go haywire and damage tiny air
sacs – the alveoli where oxygen normally flows into our blood.
Transcription:
Hi, It¡¯s Laura. We know this is a hard time. Deep Look¡¯s here for you.
We have tons of resources about this pandemic to share. More after the
episode.Viruses have lived on Earth for billions of years, mutating and
adapting.They've been around longer than animals, longer than plants.
They¡¯re neither dead nor alive. They¡¯re active inside a living thing,
powerless out in the open, but rise again in another host.
Their goal is simple: to persist.They infect our cells, then replicate and
spread. Smallpox. AIDS. Polio.These are just some of the diseases caused
by viruses that have ravaged humankind. Now we¡¯re facing a new
disease: COVID-19, caused by the coronavirus.Our bodies and communities
are struggling to fight back. An individual virus particle,or virion, is invisible to
our naked eye. It takes roughly a thousand coronavirus particles to span the
width of a human hair. It travels lightly: A virus is just genetic material wrapped
in a layer of protein and fat ¡¦ spreading through the air in moisture
droplets ¡¦or on surfaces ¡¦ finding its way into our eyes, noses and mouths.
Inside, the coronavirus hijacks the cells in the back of our nose, replicating and
spreading downward – infecting healthy cells along the way. Some viruses,
like ones that cause the common cold, infect our nose and throat. Others can
cause viral pneumonia – that usually infects smaller areas of just one lung.
The coronavirus packs a vicious double punch: it can infect the entire respiratory
system¡¦ all the way down to millions of tiny air sacs called alveoli.
Here is a single,healthy alveolus. Right next to it, there¡¯s a thin blood vessel:
a capillary.This is where one of our most life-sustaining exchanges
happens: the alveolus brings oxygen into the bloodstream and excretes
carbon dioxide. But the virus disrupts this whole process. This immune cell,
a macrophage, attacks it.Sometimes it defeats the virus. If our body needs
more help, it recruits more immune cells – like these neutrophils.
While they¡¯re attacking the virus, they can end up injuring the alveolus,
too ¡¦ breaking down its walls.
Fluid rushes from the blood vessels into the
alveolus ... filling it up and blocking the exchange of oxygen.
Now it¡¯s much harder to breathe. It's ultimately this two-pronged attack that
makes the coronavirus so deadly: the attack from the virus, and our immune
system¡¯s explosive response. All this can lead to acute respiratory distress
syndrome –what most people with COVID-19 die from. Viruses don¡¯t benefit
from wiping out their hosts. They rely on us, so they can exist.
To ultimately beat this coronavirus,we¡¯ll need an antiviral medication or immunity
through a vaccine. The impact from this pandemic has been devastating.
But we can learn from it, so we can stay a step ahead of the next one ¡¦
because there are almost certainly more to come.
Questions:
1. How long have viruses lived on earth? What are their goals?
2. Enumerate the some of the diseases caused by viruses that ravaged humankind.
What new disease are we facing now?
3. Explain how the coronavirus attacks your lungs.