The Immune System Explained I – Bacteria Infection


Every second of your life, you are under attack. Billions of bacteria, viruses, and fungi are trying to make you their home. So our bodies have developed a super complex little army with guards, soldiers, intelligence, weapons factories, and communicators to protect you from…well…dying For this video, let’s assume the immune system has 12 different jobs. For example, kill enemies, communicate, etc. And it has 21 different cells and 2 protein forces These cells have up to 4 different jobs. Let’s assign them. Here are the interactions. Now, let’s make this understandable. First of all, let’s add colors to the jobs. Now let’s illustrate the cells. The central color represents the main job of the cell. While the surrounding ones represent secondary duties. Now the immune system looks like this. Now the interactions. Isn’t this complexity just awesome? For this video we will only talk about these cells and ignore the rest. So, what happens in the case of an infection? It’s a beautiful day, when suddenly, a wild rusty nail appears and you cut yourself. The first barrier of the immune system is breached: your skin. Nearby bacteria seize on the opportunity and enter your wound. They start using up the body’s resources and double their numbers about every 20 minutes. At first, they fly under the radar, but when a certain bacteria population is reached They change their behavior and start to damage the body by changing the environment around them. The immune system has to stop them as fast as possible. First of all, your guard cells, known as macrophages, intervene. They are huge cells that guard every border region of the body. Most of the time, they alone can suffocate an attack because they can devour up to 100 intruders each. They swallow the intruder whole and trap it inside a membrane. Then the enemy gets broken down by enzymes and is killed. On top of that, they cause inflammation by ordering the blood vessels to release water into the battlefield so fighting becomes easier. You notice this as a very mild swelling. When the macrophages fight for too long, they call in heavy backup by releasing messenger proteins that communicate location and urgency. Neutrophils leave their patrol routes in the blood and move to the battlefield. The neutrophils fight so furiously that they kill healthy cells in the process. On top of that, they generate barriers that trap and kill the bacteria. They are, indeed, so deadly that they evolved to commit suicide after five days to prevent them from causing too much damage. If this is not enough to stop the invasion, the brain of the immune system kicks in. The dendritic cell gets active, it reacts to the signals of the soldiers and starts collecting samples from the enemies. They rip them into pieces and present the parts on their outer layer. Now the dendritic cell makes a crucial decision. Should they call for anti-virus forces that eradicate infected body cells… or an army of bacteria killers? In this case, anti-bacteria forces are necessary. It then travels to the closest lymph node in about a day. Here, billion of helper and killer T cells are waiting to be activated. When T cells are born they go trough a difficult and complicated training process and only a quarter survives. The surviving cells are equipped with a specific set-up. And the denditric cell is on its way looking for a helper T cell with the set-up that’s just right. It’s looking for a helper T cell that can bind the parts of the intruders which the dendritic cell has presented on its membrane. When it finally finds one, a chain reaction takes place. The helper T cell is activated, it quickly duplicates thousands of times. Some become memory T cells that stay in the lymph node and will make you practically immune against this enemy, Some travel to the field of battle to help out. And the third group goes on to travel to the center of the lymph node to activate a very powerful weapons factory. Like the T cells, they are born with a specific set-up and when a B cell and a T cell with the same set-up meet, hell breaks loose. The B cell duplicates rapidly and starts producing millions of little weapons. They work so hard that they will literally die from exhaustion very fast. Here helper T cells play another important role, they stimulate the hard working factories and tell them: “Don’t die yet, we still need you, keep going!” This also ensures that the factories die if the infection is over so the body doesn’t waste energy or hurt itself. But what is produced by the B cells? You’ve heard of them of course, antibodies, Little proteins that are engineered to bind to the surface of the specific intruder. There are even different kinds of antibodies that have slightly different jobs. The helper T cells tell the plasma cells which type is needed the most in this particular invasion. Millions of them flood the blood and saturate the body. Meanwhile, at the site of infection, the situation is getting dire. The intruders have multiplied in number and start hurting the body. Guard and attack cells fight hard, but also die in the process. Helper T cells support them by ordering them to be more aggressive and to stay alive longer. But without help they can’t overwhelm the bacteria. But now, the second line of defense arrives. Billions of antibodies flood the battlefield and disable lots of the intruders, rendering them helpless or killing them in the process. They also stun the bacteria and make them an easy target. Their back is built to connect to killer cells, so they can connect and kill the enemy more easily, Macrophages are especially good at nomming up the bacteria which antibodies have attached to. Now the balance shifts, in a team effort, the infection is wiped out. At this point, millions of body cells have already died, no big deal, the losses are quickly replenished. Most immune cells are now useless and without the constant signals they commit suicide, so as not to waste any resources. But some stay behind: the memory cells. If this enemy is encountered ever again in the future, they will be ready for it and probably kill it before you even notice. This was a very, very simplified explanation of parts of the immune system at work. Can you imagine how complex this system is, even at this level, when we ignore so many players and all the chemistry. Life is awfully complicated, but if we take the time to understand it, we’ll encounter endless wonders and great beauty.

100 comments

Cool guys: *making fun of the Immune System
Me: STOP MAKING FUN OF THE IMMUNE SYSTEM……..!!!
Immune System: we protect u and u make fun of us
Cool guys: gets sick
Immune system: SHINZOU WO SASAGEYO!!!
Also Immune System: we won cells!!!
Cool guys: HI I RESPECT THE IMMUNE SYSTEM!!

AND THE WHOLE PROCESS HAPPENS AGAIN….

Hopefully this let cool guys stop making fun of the Immune system…

I’ve been sick for 12 days now 🙈 Really want to improve my immune system I keep getting sick this year. Love this video my minds blown!!

Long story short, your red blood cells control the country, illnesses are terrorists, and white blood cells are the military of said country

Life is awfully complicated, but if we take the time to understand it, we we'will encounter endless wonders ad great beauty.

Damn that really moved me

me: gets a cut
me:nah everything is fine
meanwhile immune system..
immune system- leme guess your home? ,
memory cells: it was and it was beautiful

Video: "Isn't this complexity just awesome?"
Me: I'M LOSING BRAIN CELLS! WHERE IS MY IMMUNE SYSTEM WHEN I NEED THEM?
Cell: Bro we just chillin.
Me: This is mutiny.
TWO HOURS LATER
Me: Ow. I just scraped myself with my nail (cause I HATE when I accidentally scratch myself).
Cell: You call US mutiny? Dude you're going to KILL yourself!
TWO WEEKS LATER
Cell: Phew, finally, we destroyed all the bacteria! I'm surprised that it didn't take as long as World War II.
Me: Oops. I got a cut…
Cells: AHHHHHHHHHHHHHHHHHHHHHHHHHHHH

Bacteria: We did it!
Soon
Bacteria: what's that in the horizon
Anti-bodies: Did you miss us
Bacteria: ahhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh!!!!!!! heeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeelp

I've had a lot of wounds, I've never cleaned them with anything or hydrogen peroxide, things like that, they've never been infected, what does that mean?

Me: *gets a cut*
Also me: “Meh, it’s probably nothing.”
Bacteria: “It’s free real estate.”
Immune system: “You’re strong, but I could snap my fingers and you’d all cease to exist.”

Me: Trips Ouch my leg… Nah its just a scratch

Meanwhile

Bacterias: AHHHHHH WE WILL OWN THIS FORTRESS

Immune System: NOT IF WE STOP YOU

Both: AHHHHHHHHHHHH

30 minutes later

Immune System: WE WON!!!

Me:man its really itchy Scratches and starts bleeding again
Also me:oh man

Immune System:YOU LITTLE SON OF A HUMAN WE PROTECTED YOU AND THIS IS HOW YOU THANK US!?!? BY MAKING US DO IT AGAIN!!!

Human: – accidentaly sticks foot on a rusty nail –

Immune system: atention base, send the air force us are going to war

C A L L O F B O D Y m o d e r n w a r f a r e

Bacteria : Touches Karen's body.

Entitled Karen : Screams YOU ARE RAPING ME. THIS IS RAPE THIS IS RAPE. I AM GOING TO SUE YOU. DO YOU KNOW WHO MY HUSBAND IS. YOU ARE SEXIST FOR TOUCHING WOMEN YOU JUST VIOLATED MY RIGHTS. I AM SOOO CALLING THE COPS YOU RAPED AND ASSAULTED ME IN 18 DIFFERENT WAYS AND YOU ARE ALSO RACIST HOW DARE YOU. YOU BACTERIA!!!!!

"And when a virgin B cell and a T cell meets a reaction takes place"
Hmmmm… are you telling me that
my cells arent virgin?

yo your body loves you more than your fake friends that you think are real.

don’t put yourself down bc of them

I thought none will metion the pokemon battle music when encountering a rusty nail

But i will

Bacteria don’t cause disease. This video just shows why people are stupid enough to believe in the germ theory. Humans love war so of course humans want to imagine disease is caused by tiny invaders and tiny warriors do their best to combat the tiny invaders. Of course in reality disease is caused by malnutrition and toxins.

Kurzgesagt: "The immune system is a powerful army of cells that fights like a T-Rex on speed and sacrifices itself for your survival"
Autoimmune disease sufferers: ;-;

OHHH, now I get it why shots exist it’s because of our memory cell so if a infection that matched what was inside the shot, the memory cell will kill it!

Me: gets a cut 0o0 puts a bandage on
Meanwhile
Immune system: factory makes more soldiers cells alright let's go
The immune system fight the bacteria, fungi, and viruses and they start a war

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