The only problem, lots of it was wrong.

Back then, the ultimate authority on human anatomy was a Greek physician by the name of Galen.

His work had dominated the field for over a thousand years, and Vesalius was a fan.

Whoa, you like Galen too?

Hell, yeah. Galen rules.

Welcome to medical school.

Lesson one will be on Galen,

lesson two will focus on Galen,

and lesson three, we will pivot 360 degrees to... Galen.

Teachers at the time literally thought it was more important to study Galen's books than the human body itself,

so much so that when they did dissections in school,

the Professor would just read a commentary on Galen and an assistant would point things out

as a surgeon chopped up the body.

The professor never even looked inside!

Now we will remove the heart.

(students ohing)

Whatever you're looking at is the heart.

(students ahing)

Uh, I love him too,

but aren't you going to check if Galen is right?

(students gasping)

As if he'd ever be wrong.

He's Galen! (laughing)

(laughing)

(laughing) Idiot.

After graduating at the age of 23,

Vesalius was given the job of Professor of Anatomy and Surgery and started doing his own research,

which is when he started to suspect that Galen wasn't as perfect as everyone thought.

They may laugh, but I'm going to do my own dissections and observations.

Let's see.

Strange.

Galen says there are two bones in the lower jaw,

but there is very clearly only one.

(cat yowls) Well, simple mistake!

Hmm. Galen says there are five lobes on a liver, but I see only two.

What is happening?

Vesalius went on to identify more than 200 instances where Galen got some aspect of basic anatomy dead wrong.

This breast bone has three segments, not seven!

Major blood vessels start in the heart, not the liver!

Could it be Galen, the father of human anatomy,

never dissected a human?

No! No! You're a liar!

I hate you! I hate you, Galen!

(Ancient Rome) Vesalius finally concluded that Galen had done his dissections on monkeys, dogs, and other animals

and simply theorized that humans were similar.

Humans have two jawbones, soft floppy ears,

and their stomachs are full of bananas!

And this incorrect anatomy

had been taught to physicians for over a thousand years!