episode_0166

Episode 166. Breath of Life (2)

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The ancient Greeks thought that air was taken out of the lungs and traveled through the arteries. They thought that when an artery was cut, blood would bleed because blood was coming from somewhere else.

This is a completely ridiculous idea.

Hippocrates also ignored the fact that breathing takes place through the lungs. Why?

I’m not sure. It might be related to the fact that breath was considered evidence of soul and life.

Later, Galen proved through dissection that breathing takes place through the lungs, and even discovered that something in the air is transferred to the blood and turns it red.

The life force that exists in the air and makes the blood red. Galen called it ‘pneuma’. A word with religious connotations.

We usually call it oxygen.

****

I continued talking.

“So, wouldn’t there be components of the lungs at a microscopic level? If you look at it in detail, the physiological structures the size of sand grains are filled with air, which is how the lungs inflate.”

“Um. Yes.”

“There is a principle that keeps the alveoli from getting wet and shrinking. That is a surfactant like oil or soap.”

“Does this mean you can explain why the lungs don’t need muscles and why they don’t normally collapse like wet balloons?”

“Yes.”

“The more I listen to the professor’s explanation, the more it seems to differ from existing academic opinions.”

I sighed.

Is it really that hard to explain the breathing process? I thought it would be easy to use a balloon metaphor, but I didn’t know it would be this complicated.

I erased all the drawings on the blackboard.

“Okay. Then let’s go back to the basics.”

Footsteps. I turned my head at the sound of footsteps.

Suddenly, a student sitting in the back moved to the front seat with a notebook and pen. I looked at the student who had just moved.

The classroom became deathly quiet for a moment.

What are you doing now?

****

A new challenger has emerged.

Since coming to the academy, I’ve seen many people yelling during class, arguing, and getting up…

I have never seen anyone move to the front to ask a question or argue.

The classroom became quiet for a moment. I looked at the student. It was a face I had never seen before. Was he a new student who had joined during the semester?

It was the first time that someone had moved during class. It was like someone walking towards me with a chair in a wrestling ring.

Well… … It was a small action, but the effect was huge. That one thing alone was enough to overpower all the students gathered in the classroom.

“What is your student’s name?”

“This is Melissa.”

“Why did you come forward?”

“I want to ask a question.”

Great, but this is a bit much.

“Surface tension or pressure. I don’t know specifically why these terms are mentioned.”

“Mr. Melissa. Why do you think people breathe, and why do you think they breathe?”

Melissa thought about it for a moment.

“Ah, to mix air with blood. As the professor discovered, as blood flows through the body, air among the four elements must move to the body and maintain balance… … .”

That’s right.

Let’s say that’s true, for now.

As for things like the Four Elements novel, rather than believing in it ‘actually’, you should think of it as providing a background for abstracting the subject. Even if you curse it as stupid, it won’t lead to a productive conversation.

It’s not entirely wrong to think of gas exchange as the interaction between air and water.

“Yes. It mixes the oxygen in the air you breathe with your blood. The oxygen in that air turns the blood in your arteries red.”

I drew a picture of the lungs, drawing lines and circles as if enlarging a part of the lung.

“Then. The process of how blood mixes with air is important. As you can see, blood doesn’t just flow from the lungs, right?”

“That’s right.”

“It means that there is a very thin film that water cannot pass through properly, but air can pass through. That is what I mean by a structure like a soap bubble.”

Structure, size is important here. It has to be a very thin and small membrane, so that it can perform the function of blocking the movement of water and dissolving air.

“That makes sense… … . What’s the basis?”

“You keep saying it. Structure and function. We need to see how structure and function are related. If we look at the microscopic structure of the lungs under a microscope, we can come to some conclusions.”

The basic unit through which air is exchanged in the blood is the alveolus. It is a balloon the size of a grain of sand, and countless alveoli make up the lungs.

“If you soak these balloons smaller than a grain of sand in water, they will naturally deflate, so there must be a substance inside them that creates bubbles like soap. Does that make sense?”

Melissa nodded.

“Yes.”

“In the same vein. Does it make sense now that lungs don’t have muscles? If you tie up such a small and fragile structure with muscles and pull it here and there, it’s sure to break.”

“I guess so.”

“Finally, when the muscles of the rib cage expand the thoracic cavity, the pressure in the thoracic cavity decreases, which reduces the force that presses on the lungs, causing the lungs to expand. That’s why air comes in.”

“Ah! Now I think I get it.”

I nodded.

“Back to the patient’s case. This is why the lungs cannot be used simply because the thoracic cavity is filled with blood. The lungs do not move voluntarily, but rather operate by pressure differences.”

Since I explained it from the beginning, maybe this is a little hard to understand? The classroom was unusually quiet today. I looked around the classroom again.

“Does anyone have any more questions?”

Professor Kropelter, who had been thinking about something, raised his hand again. His eyes looked as if he had found a loophole. What is it this time?

“Yes, Professor.”

“Is there a patient currently hospitalized who received treatment to drain fluid by inserting a tube into the lung where the problem was?”

I nodded.

I feel a little sorry for Daisy, because everyone here will be flocking to see the patients being treated with the new technology.

“I see.”

“Are there any risks to having a chest tube inserted? It doesn’t seem safe.”

It is not safe. It is dangerous to put any foreign substance in the body. So hygiene management and preventive antibiotics are necessary.

“Good point. We also administered antibiotics to this patient as a preventive measure before the procedure to minimize the possibility of infection.”

Professor Kropelter thought about it for a moment longer.

“It’s a bit ironic. Putting a tube in the lungs to drain water directly seems to be the opposite of the ‘do no harm’ medical practice that has been taught as a creed since long ago.”

“That’s true.”

Why did Hippocrates establish ‘do no harm’ as the first principle?

That’s because there were many people who burned the anus with a pharynx because the baby had hemorrhoids and prescribed morphine because the baby coughed. The above two cases were not completely ineffective.

Professor Kropelter continued speaking.

“In particular, it is surprisingly similar to the logic used by those who supported surgical treatment of tuberculosis. In terms of attempting to operate on the lungs.”

Surgical treatment for tuberculosis?

“Ah.”

As expected, experience cannot be ignored.

A sharp question that gets to the heart of the matter. The essential question is whether it is safe to insert a tube into a patient’s chest cavity, and how useful is it?

In 19th century Britain, tuberculosis was also treated surgically, either by removing a lobe of the affected lung or by surgically inducing a pneumothorax.

I think that’s probably what it was about. I don’t know how meaningful that method was. I don’t think it would have been very useful.

In the end, the criticism was that you were saying the same thing as the quacks who tried to cure tuberculosis by sticking a knife in the lungs.

“Are you saying that this evidence justifies the risk of stabbing the lungs?”

“Yes.”

“That’s a complicated story. First of all, it’s true that pulmonary tuberculosis cannot be treated surgically. The professor is right about that.”

“Then. What’s the difference?”

“There is no solution to the problem of water or blood filling up the thoracic cavity other than draining the water from the thoracic cavity. If you don’t drain the water, the price is high.”

Unlike surgery for tuberculosis, where the benefits of treatment are unclear, inserting a chest tube to drain fluid or air has immediate results.

First of all, you will immediately see the liquid coming out, and you will hear the breathing sounds change, right?

“First of all. If you do this, you will be able to see the water draining from the thoracic cavity and immediately determine if the breath sounds are normalized, right?”

The advantage is that you can see the results right away. Tuberculosis is incurable anyway. Professor Kropelter nodded.

“It’s a bit different… … .”

The lecture was slowly coming to an end. I never thought of comparing it to tuberculosis surgery.

“Then. If there are no more questions, we will end today’s lecture here.”

This concludes the lecture.

I greeted the students and professors gathered in the auditorium and then left the classroom again.

The dissection will be performed tomorrow.

If we examine the lungs in the corpse and see if they are inflated, and then cut out some lung tissue and examine the fine structure of the alveoli, we can come to a conclusion.