"Good morning class."

"Good morning Doctor Rhodenberger..."

The wolf with his thick glasses was a bit old school. The entire class stood up and greeted him with a level of discipline that most of the other teachers no longer managed to squeeze out of the horde of squirmy third graders. But with his friendly face, the grey haired wolf was more respected than feared. He insisted on some formalities, but then again he laughed with the class about some pranks that other teachers would send you to the principal for detention. Like that one time Tommie had filled the waste bucket full of water and arranged it on the entrance door.
Everyone had had a laugh, but the teacher hadn't even asked who had placed the bucket up there. Today however wasn't about fluid physics. Today it was biology class.

"Sit down everyone. As I promised last week, today we are going to learn about the heart. Who knows already what the heart does?"

Curious the Ferret rose his hand, along quite a few others, but Meggie the squirrel was quicker.

"Yes Meggie?"

"It pumps the blood through our bodies..." she said while cutely feeling her own chest for the little bumping sensation. It almost looked as if she was blushing a bit.

"Correct, that it does. Every second, every day, every night. Over the course of a lifetime each of your heart will beat well over two billion times. But it can do a lot more than just pump blood day in and day out. I'd like to show you all, but I need a volunteer. Who wants to volunteer this class."

"Me! Me!" Curious was quicker this time. Meggie hesitated a bit, she was a bit too shy. Unlike Jane. The little bunny girl in first row tried desperately to get the teachers attention.
"Pick me Doctor Rhodenberger!" She pleaded with all the cuteness the little bunny girl could muster.

The wolf smiled at her. "Awww Jane, give others a chance too. You were already volunteering last week. How about... Curious? Yes that will do, and then Jane can do next week when we learn about the reproductive organs. Shall we?"

Jane beamed. The little bunny already knew quite a bit about reproductive organs, she was really proud of hers. She squealed happily, which caused a few giggles around her.

"Curious, why don't you come forward and lay down on my table so everyone can see you. Here, let me put my pens out of the way, we don't need them today."

The ferret felt his heart beat like a drum already as he stepped forward. If that was what it took, he'd make an awesome volunteer, although the giggles and stares from the rest of the class made him a tiny bit nervous. He stepped on the teacher's chair to get on the desk, then laid down.

Doctor Rhodenberger smiled warmly at Curious before he produced a stethoscope from one of the drawers of his desk. “This might feel a bit cold at first,” he said as he placed the end of it on Curious’ chest, moving it a bit as he listened to his heartbeat and tried to get the clearer sound he could.

“There we go,” he added with a smile. “Beating fast and strong, a bit faster than normal. I’d say someone is either slightly stressed or excited,” added the teacher while he looked at Curious. The young ferret blushed and squirmed a bit, smiling a bit coyly at his teacher.

“Class, for the first exercise of today, we’ll start by listening to our own hearts,” announced the wolf as he placed the stethoscope aside temporarily. “You’ll find one such device, called a stethoscope, in the big box against the wall. Grab one and get back to your place. No need to run, there’ll be enough of them for every one of you.”

Moments later, every kid had a stethoscope and was sitting back at their places. Most of them were curiously studying the device, some of the pupils putting them on like they saw their teacher do.

“Good. Now, curious, sit on the edge of the desk, please,” said the teacher while he helped the young ferret to sit. “The heart is located about here,” he continued, showing the position with his fingers. “If you place the end of the stethoscope here, you should be able to listen to your own heartbeat.”

Several gasps could be heard coming from the class when they heard the strong and steady beatings of their own hearts.

“This is your heartbeat at rest, when you’re not exercising or not having intense emotions, like being scared. Your heart will beat slower when you’re fully relaxed, like when you’re asleep, and faster when you’re playing, running or watching those scary movies you’re all afraid of but still watch anyway,” he said with a smile, drawing many chuckles from the class.

“Alright, try to listen to the heartbeat of your classmate on your right while I prepare the rest of the class,” said the teacher. “Lay back down, Curious, I’ll be back in a minute.”

Curious laid down on the desk, while the other pupils marveled at the sound of each other's heartbeat, and the teacher was back moments later, carrying with him some sort of medical apparatus.

“This is a cardiogram,” he said while pointing at a screen with a green flat line on it. “It will allow us to see and hear Curious’ heartbeat throughout the rest of the class, so you can all see and hear how it changes through the various tests we will perform.” He paused and looked down at the ferret. “I’m sorry Curious, but I’ll have to shave some of your fur to place the electrodes upon you, they wouldn’t stick on fur.”

Curious smiled and nodded. “I don’t mind, my fur can regrow.”

Two minutes later, Curious had a bare patch on his chest and three sensors from the cardiogram stuck to his naked skin. The rhythmic beeps of the cardiogram echoed through the classroom while the green line on the screen moved along with the ferret’s heartbeat. The whole class had put aside their stethoscopes and was listening and watching, transfixed and amazed.

“The line on the screen can give many information to doctors and medical professionals on the health of someone’s heart,” explained Doctor Rhodenberger. “For now, suffice to say that Curious’ heart is strong and healthy, as can be expected for a young ferret of his age.”

“The heart is an autonomous organ. That means that the organ works without your conscious input, via a thought or a movement. When you grab something with your hand, it is in response to to a thought, to a will. The heart doesn’t need it to keep on working. Thus why it doesn’t stop when you’re asleep, for example. Let me demonstrate.”

The wolf grabbed a gas mask from his medical suitcase, turned the knob on a bottle nearby and held the mask against Curious’ snout.

“Curious, I’ll need you to take deep breath now. Don’t worry, this will only put you asleep,” he explained to the ferret. “This is a gas called N2 or nitrogen. What it does is replace the molecules of oxygen in your blood cells, and without oxygen you lose consciousness. It is odorless and quite fast-acting.”

Curious nodded and began breathing deeply. He couldn't smell the gas coming from the mask, though he tried nevertheless, and felt nothing different at first. After a couple deep breaths, however, he began to feel very tired. The young ferret yawned and his eyelids started to feel heavy and closed on their own.

On the screen, the line that showed his heartbeat started to change as he relaxed. The constant beeping got noticeable slower. Moments later, Curious was sound asleep, his body laying down on Doctor Rhodenberger’s desk, completely relaxed.

“As you see, Curious is now completely asleep, and his heart is still beating, albeit at a slower pace. You can see that the line has the same shape as before. Actually, his heart isn’t really beating slower: it beats at the same speed, just less times per minute.”

A young calico cat raised his hands, a bit excitedly, to get noticed by the teacher.

“Yes Tommy, what’s your question?” asked the teacher.

“What happens if he keeps breathing the nitrogen and there's less and less oxygen in his body?” asked the young feline.

“An excellent question. If the level of oxygen drops too low, the heart will simply stop working. Oxygen is part of the fuel that is needed to make our bodies work. Without oxygen, our organs will just shut down, starting with the heart, thus stopping the flow of blood throughout our bodies, and we’d die soon after. Fortunately, medicine has ways to restart a stopped heart, provided it is done quickly. Watch closely, let's demonstrate that!”

The class leaned forward on their desk to watch more closely. Tommy couldn’t hide his grin, his tail flicking back and forth happy. The teacher was about to kill Curious, and he silently wondered if he could really wake him up, and what would happen if he couldn’t. Not that he really wanted to see his buddy Curious die, but he still thought that it would be quite cool to see someone die that way during a biology class, and Curious would be famous forever as well, even if posthumously.

The teacher placed the mask back on Curious and turned the knob again to let the N2 flow. As Curious breathed in the gas, the beeping from the cardiogram began to get slower and slower, the line showing less and less heartbeats per minute. Soon, an automatic alarm began sounding when the ferret’s heartbeat went below a certain threshold, to inform anyone nearby that he was at risk of cardiac arrest. Doctor Rhodenberger quickly silenced the annoying alarm, but kept the nitrogen flowing.

Curious began to twitch some in his induced sleep, his body protested against the low levels of oxygen, but nothing could be done. Moments later, after one final twitch of his limbs, his body relaxed and the line on the cardiogram became entirely flat.

There were some gasps coming from the class when Curious died in front of them: They could all see the difference between sleep and death in the way his body completely relaxed, his tail dangling limp from the side and even the way he was laying down on the desk. There was nothing fully different, but a myriad of tiny details that showed that his heart had stopped beating.

“As you can see there, his heart has stopped beating,” explained the teacher while pointing at the flat line. “Without a heartbeat, blood isn’t flowing through the veins and oxygen and nutrients aren’t being delivered to the organs and the rest of the body. Meaning his organs will soon start to malfunction and eventually die as well.”

The old wolf quickly removed the electrodes and activated the defibrillator that was placed beneath the cardiogram. The machine hummed to life, drawing curious looks from the pupils, and he quickly programmed to charge up just enough to restart the heart of a healthy cub like Curious.

“This is called a defibrillator. You probably saw something similar in those tv series. What it does is send an electric shock to the heart to force it to restart, much like you can jumpstart an engine with a new battery. It will take a bit to charge, just enough for me to supply Curious with pure oxygen, to help with the jumpstart.”

Doctor Rhodenberger switched the N2 mask on Curious face for one linked to a bottle of pure O2 and he opened the valved, checking to make sure that O2 was flowing freely.

“Matt and Majolm, come here and hold his arms and legs. The electric shock might make him move and fall down the desk, and we don’t want that,” he asked to two of the pupils, a tiger and a wolf, who were among the strongest of the class. Once the boys were at their positions, the teacher grabbed the defibrillator pads and placed them on Curious chest.

“Hold tight,” he warned them before pushing the button to deliver the electric shock.

Curious body arched, but the two boys held him despite the surprise. Not that they had much of a choice, as they got just as much of an electric shock as he did. Their fur stood up and they stood, involuntary on their paw-toes while a few yelps of surprise could be heard coming from the class.

The cardiogram reacted to the shock. A single peak, but then flatline again, prompting the teacher to increase the level of the shock and do it again. Matt and Majolm had barely recovered and reluctantly held Curious arms, when he sent the next shock through all three.

This time, the cardiogram showed a heartbeat, much to the relief of the teacher and the whole class. 

“There, Curious is back within the living,” said Doctor Rhodenberger with a smile, before he motioned for the two helpers to go back to their seats. Their fur stood up in all directions, and they were shaking a bit, but their smile told everyone that they were having a blast...

“Of course, like every engine, going too slow isn’t the only way to break it and cause it to stop. Oxygen deprivation is similar to when an engine runs out of fuel. But, if you give it the wrong kind of fuel or push it too far, the engine will also break, and so would the heart. As you’ve seen, the rate of heartbeat varies. If it gets too slow, the heart stalls, if it gets too high, it will stumble, like you during recess, when you try to run too fast, fall over your own feet and land on your noses...”

Doctor Rhodenberger opened a small box that was right besides the defibrillator and produced a small syringe filled with a clear liquid.

“This is called ‘atropine’. It’s a natural compound found in many plants. It has been used as a drug by people and in medicine for a long time. It’s main use is to make the heart beat faster, and it is used in many treatment against heart illnesses. Of course, as with every drug, dosage is crucial!"

What I have in this syringe is enough to make Curious’ heart beats too fast and go into fibrillation.” He Injected the atropine into the ferret’s arm while he spoke and continued to explain.

“Basically, fibrillation means that the beating of his heart isn’t synchronous, as if all the parts were not working together, which will cause it to stop, much as it would on an engine. You see all the spikes on the heartbeat of the cardiogram? Each spike up and down is like a part of the heart doing it’s job in turn. When they’re all working in sync, everything is fine, if they are not synchronous, then problems start to happen.”

“It takes a minute or two to work, just enough time for me to prepare to resuscitate Curious once again. This time I’ll use adrenaline,” he said as he produced another syringe, a bigger one, from the box. “This syringe will allow me to inject it directly into his heart, which will have a similar effect than the electric shock delivered by the defibrillator.”

Doctor Rhodenberger placed the syringe aside when Curious began to twitch again and the teacher held him tight to prevent the young but still unconscious ferret from falling down his desk. The cardiogram showed that his heartbeat was accelerating suddenly, and the line on the screen showed that his heartbeat was quickly becoming erratic. Indicators flashed to indicate fibrillation, silently since the teacher had turned the sounds of the alarms off.

The line became more and more chaotic for about a minute, then it suddenly straightened into a line when his heart gave up. The ferret’s body twitched one last time and fell down limply on the desk again. Curious had just died a second time.

Grabbing the large syringe of adrenaline, Doctor Rhodenberger stabbed Curious in the heart with the ease that comes with a long practice, and emptied it, drawing gasps from the pupils again. The young ferret shook, and the wolf quickly discarded the syringe and began an external massage to help it restart and keep on beating.

“This is called a ‘cardiac massage’, something you’ll learn in your first aid lessons later. Basically, i’m helping the heart restart by exerting a rhythmic pressure on it. The pressure acts as if the heart was working, pumping the blood, and the adrenaline, through his veins and arteries, and help the heart pick up the rhythm and beat on it’s own as well.”

A short moment later, the cardiogram showed that Curious’ heart was indeed beating on it’s own again, and the teacher stopped the cardiac massage, rubbing his shoulders a bit. “A good cardiac massage requires strength, but it must be adapted to the patient. If I would have used all of my strength on Curious, I could have broken his ribs. But don't worry about that too much when you give someone first aid. A few broken ribs heal better than a broken heart... ”
Some of the class chuckled.

“Although, for the last part of this lesson, I’ll indeed have to break some of his ribs,” he added after a short moment of silence, while he checked Curious’ vitals. “Because, after speaking about it so much, it is time to show you what a heart actually really looks like!”

Excited cheering could be heard while the teacher took a scalpel from the same box where the syringes were stored and a good supply of tissue. He cut several lines across Curious’ chest, using the tissues to soak up whatever blood spilled as he cut through the young ferret’s pelt, then he carefully peeled the flesh to the side to reveal his ribcage.

Carefully, the teacher cut through the ferrets ribs, removing them one by one until the ferret’s beating heart was finally fully exposed. 

“Class, come closer. No running!” said the teacher. “It’s time you saw what the heart looks like with your own eyes.”

The whole class got up from their desks and walked to surround the teacher’s desk, looking with much curiosity and awe at Curious’ open chest. Quite a lot of them brought their hands to their own chests, as if trying to feel their own heart through the layers of fur, muscles and bones protecting it.

Meanwhile, Doctor Rhodenberger grabbed the O2 mask and placed it on the young ferret’s muzzle, turning it on to wake him. After all, Curious was also a student and would benefit from the last part of the lesson as well.

“If you look closely at Curious’ heart, you can see how that which we call ‘beating’ is actually the heart contracting to push the blood through the arteries. Look closely, and you’ll see that the ‘beat’ is actually two-timed, which is reflected in the cardiogram.”

The pupils’ gaze moved between the ferret’s heart and the cardiogram. They were all quite fascinated by the sight, and by the way the heart kept it’s rhythm all on it’s own, perfectly timed.

Curious soon began to stir and open his eyes, his heartbeat increasing as he regained consciousness. A few of the pupils touched or poked his heart, quickly moving their fingers away when they felt the beat, giggling amongst themselves at the feeling.

“Welcome back to class,” said the old wolf to the young ferret with a warm smile. “How are you feeling?” He asked as he put the mask away and turned the flow of oxygen off.

“I’m ok, bit sore,” replied Curious weakly, as he looked around, taking in his surroundings, wondering why everyone was so close, before he noticed the gaping hole in his chest and saw his beating heart exposed to the view.

“That’s good,” resumed the teacher. “Then you can be with us for the last part of the lesson.”
He turned his attention back to the class.

“This is what the heart really looks like. No, it’s not shaped the way everyone draws it, although it’s not completely that far off. Those big tubes are called ‘arteries’. They serve to bring the blood in from all over the body over here. It fills up the heart here, moves when the heart contracts to that chamber there. Then the blood is expelled into that big artery there, from where it goes to Curious' lungs. In the lungs it gets filled up with oxygen, then comes back to the heart here on the other side. You could say the heart is actually two pumps. One pump to pump the blood from the body to the lungs, and the second, identical one to pump it back into the circulatory system. Arteries are like the highways for the blood, we have main arteries going to the brain and the limbs, then the blood gets into smaller blood vessels, smaller roads, to supply every part of our body with nutrients and fresh oxygen.”

Curious was half-listening to the explanation, his gaze transfixed on his own beating heart exposed, much like most of his comrades.

“Of course, depending on many factors like your species and your age, the heart can get more or less big. You are all still young, and your heart with grow bigger as you age,” explained the teacher.

“You can touch it, Curious first, it’s his heart after all, to feel it beat. Just place your hand gently on top of it, and feel how it beats and how the blood rushes in and out.”

The ferret approached his hand slowly, a bit hesitant, and everyone could notice his heartbeat accelerating. This drew some chuckles from the other pupils and a smile from the teacher, while Curious’ cheeks got a nice rosy tint to them as he blushed.

He let out an excited sound when he finally placed his paw over his heart, his eyes open wide as he felt the organ under his fingers. It felt soft, seemed to be coated in a slightly slimy substance, yet each beat felt so very strong, like a mini-tremor right under his paw. It was so amazing to feel it pump the blood in and out. The rush of the life fluid throughout the constantly pulsing organ...

Curious stared for a moment, transfixed, then he gave his heart a little squeeze and immediately gasped. It felt like his heart nearly skipped a beat, and the cardiogram briefly flashed an alarm, thinking his heart was going out of rhythm again.

“Curious, the lesson is not over,” admonished the wolf, though with a smile. “Let your comrades get their turn at touching your heart. There’s still one more experience to do before I can let you all go into recess, don’t worry.”

Blushing some more, Curious nodded and placed his hand away so the others could touch his heart. That was experience that none of the pupils would forget, whether it was Curious or his friends.

The ferret kept on blushing throughout. It felt even stranger yet very nice to have every other pupil touch his heart. The feeling of their hands laying on his beating heart felt so intimate and nice. There were some who barely touched it, more like a feather touch than an actual touch, as if afraid. Some others quickly pulled their hand away with a giggle, as if they had been caught red-handed with their hand in the cookie jar. And others who were more bold in their approach, placing their hand flat on his heart, fingers spread to feel as much as they could, smiling and amazed at the feeling.

One of the pupils, a young white rat, seemed to have an almost religious experience: she closed her eyes to focus on the feeling. Curious and some of the others around could swear that she timed even her breathing with his heartbeat.

Tommy, the curious calico cat and one of Curious’ best friends, gave his heart a couple squeezes, timing them to try and counter it’s beating. The ferret gasped again at the feeling and Tommy was quickly chased away by Doctor Rhodenberger.

“Of course,” resumed the teacher once everyone was done, “the heart also needs to receive fresh blood itself, to function. See those smaller blood vessels?” He said as he pointed to a specific part of the heart.

“They’re called the coronary arteries, and they serve to feed the heart itself. If they become clogged and blood doesn’t flow to the heart, then the heart stops working, it’s called an infarctus. Curious, would you like to help me demonstrate?”

“Yes, doctor Rhodenberger,” replied the young ferret while he nodded eagerly. 

“Good. Then place your hand inside, against your heart. Now feel around,” instructed the teacher as he and the class watched intently.

“Move it to the right a bit,” he told Curious, guiding him as the ferret moved his paw around. “You should feel the big vein that is one of the coronaries. There, that’s it. Now move your hand up a bit, follow the vein, you’ll feel it get thicker as you go further up, until it almost joins one of the main arteries that brings blood to your heart. Stop there, that should be good. Can you feel how the blood pulses inside with every beat of your heart?”

Curious nodded, his fingers touching ever so gently to feel it better. It seemed as if he was almost caressing the vein. He couldn’t see much from his point of view, and he was a bit envious of his classmates who had a better vantage point. Although he absolutely loved the fact that he had been chosen and he was the one able to touch his heart.

“Good. Now you’ll need to pinch it to stop the flow of blood, and hold for as long as you can. Then I’ll revive you with another cardiac massage. It will be a good demonstration for anyone, and it will give you a headstart on the first aid classes too.”

Curious gulped, a bit hesitant. But then he obeyed and pinched hard on the coronary.

It didn’t take long before his heart began beating erratically, prompting the cardiogram to flash an alert again. The young ferret took sharp breathe, the feeling of his heart struggling to keep on beating as it was deprived of blood, thus of energy to keep on beating, not being the most pleasant. There was a sting, almost like a cramp in his chest.

The other students watched in awe, most of them having their eyes transfixed either on Curious’ heart or his face. Tommy was absolutely fascinated and his gaze switched between both the ferret’s heart and face as his friend was basically killing himself.

The old wolf reached in and helped Curious keep his grip on the coronary when he saw the ferret’s grip begin to slip. He held Curious’ fingers while his heart beat more and more erratically, making the ferret gasp and squirm against the pain. Everyone except him could see his heart give one last strong beat before it went completely still.

But he also felt it!

It was as if a great calm had fallen upon him, as he couldn’t hear or feel the beating of his own heart. One of the sounds and feeling that nobody ever fully acknowledges consciously until it stops. Curious body began to relax as darkness enveloped him. The line on the cardigram was flat, and he could barely hear the teacher or his classmates chatter around him. His vision faded, as if he was suddenly watching at everything through a tunnel that became narrower and narrower. He felt as if he was falling, tumbling... and then he lost consciousness, not hearing Doctor Rhodenberger's next words at all.

“I hope you’ve watched attentively,” lectured the teacher, after the ferret’s heart stopped. “You’ve witnessed an infarctus in a way not many would have seen before.” He paused and glanced at the cardiogram that was still flashing it’s alert and displaying the flat green line.

“I’m sure you’ve heard the word on one of those TV shows. Now, as you can see, when I moved the obstruction and allowed blood to flow again, his heart didn’t restart. Can anyone tell me why not?"

Janet's hand rose, hesitantly.

"Because... his heart isn't beating... so no blood flows?"

Doctor Rhodenberger nodded with a smile. "That’s exactly why. Just like with the engine of an old lawnmower, putting in fuel and ignition isn’t enough, you also need to yank the pull cord to make the engine spin to make it start. With his heart accessible like that, I can just give him a heart massage to make it restart. Watch!”

The old wolf slipped his hands into Curious’ ribcage, grabbed his heart gently and began applying a rhythmic pumping motion. He forced it to move almost the same way it had beaten on its own before, and each squeeze, indeed, made the big arteries in Curious' chest bulge with a rush of blood moving through them.  As soon as he started, the green line on the cardiogram reacted, much to the amazement of the pupils.

“When the heart stop, you do not die right away. Your organs have a small supply of oxygen and nutrients and can keep on working for several minutes without any lasting effect. Thus why we can revive someone with a cardiac massage. It is similar to what I did before, except this time I’ll be massaging his heart directly instead of applying pressure on his chest, but the result is the same.”

“As before, you need to maintain a steady rhythm and apply just enough pressure. Too little, and it will have no effect, too much and run the risk of damaging the heart,” he explained as he continued to massage the ferret’s heart. “What I’m doing when I massage his heart is force the blood to flow, thus make it bring nutrients and oxygen to itself, through the coronary, which is basically the spark that makes it restart.”

Moments later, the heart started pumping on it’s own. Doctor Rhodenberger continued to massage it for a bit, until he was satisfied that Curious’ heart would keep on pumping and had gotten back to a nice and steady rhythm.

“There, he should regain consciousness on his own in a moment. I’ll take this time to patch him up,” said the teacher. “Meanwhile, you all go back to your desks and note down everything you’ve seen today, there will be questions about it on the next test!” He told the students.

Some 'awwww' and similar slight sounds of disappointment could be heard. The exciting part was over and making notes was not nearly as fun as watching Curious' heart being experimented on, but when Doctor Rhodenberger said there'd be a test, there always was a test. Everyone knew that.

So the class went back to their desks and began writing. The silence was only broken from time to time by someone asking a neighbour to help with some details. The old wolf checked Curious vitals again, then he grabbed various utensils and began to patch up the ferret boy. He made sure the ferret’s heart was nicely clean, since it had been touched a lot, then placed the ribs back and sewed his pelt back on before covering the wound with a large bandage.

By the time Doctor Rhodenberger had finished patching Curious up, the young ferret had awoken and the bell rang, signaling the end of class for the day. With a lot of chatter, the students ran out, excited as always about the lesson they had just had. "That was so cool, did you see it twitch?" "I wanna hold my own heart too..."

The old wolf took Curious to the side.

“I’ve noticed that you seemed to really like to touch your heart, so I added a little surprise for you when I patched you up. Go on, take a peek under the bandage,” said the teacher.

Curious removed a bit of the bandage to look under it, and smiled when he saw a zipper on his skin.

“Wait a bit before using it, your skin need to heal up some. At least 3 days! Make sure to always keep it clean, and don’t go stopping your heart until there's someone nearby to restart it for you, ok?”

“Yes, teacher! Thank you!” replied the young ferret, beaming with happiness.

“You’re welcome. Now go, time to get back home.”

THE END.