Dad: Do you want to hear a story tonight? Okay, why don’t you pick it out? This one again! “How’d I Get a Brain?” By me and your mother.
Nine months before you were born, you didn’t have a brain,
You were just a single cell, inside of a membrane.
This single cell, this zygote, it started out from two,
Half from Mom and half from dad, but all of it was you!
After one day you split in two, you were duplicated,
Your DNA was doubled too, it was replicated!
You next turned into a blastocyst made of many cells,
You looked just like most baby chicks, inside of their eggshells.
Next you formed two bubbles, one is the yolk sac.
Later this will form blood vessels and part of your digestive track
The other bag is the amnion it's full of H2O
It protected you from any harm when you were an embryo.
At this time your brain got started, inside this encapsulation,
This process makes us who we are, and we call it gastrulation.
You formed as three germ layers where these circles meet,
and your whole body came from these, from your head down to your feet!
The brain comes from one of these layers, this we can confirm,
It's the top most layer here, it’s called the ectoderm!
The mesoderm’s the next one and the last is the endoderm,
And this is what you once looked like, a tiny little worm!
Your ectoderm made the neural groove, then folded like a wrap
Then it was called the neural tube, once you closed this little gap,
From this tube your brain was formed, your spinal cord was too,
Amazing how from a few small cells, your whole nervous system grew!
Next the tube grew longer, some divide it into parts,
We call the front the Proencephelon, and it's what gives us all our smarts.
Next comes the Mesencephalon, it's the part that’s in between.
Later in life it will help to keep all your senses keen.
Last is the hindbrain, the Rhombencephalon,
This connects to the spinal cord, which it rests upon.
Next we would call you a fetus because you’re eight weeks old
Look how big your head was, imagine what it could hold!
Over the next seven months, your body elongated
Although your brain still grew, your head looked less inflated.
While your brain expanded, it made ridges called gyri
These are found along the cortex, their grooves are called sulci.
These bumps and valleys are vital, as they allow our brain room to grow,
This means we’re smarter than other primates, like the apes in Borneo.
Your brain looked very bumpy from the moment of your birth,
But your brain will change so much more, during your first few years on Earth.
Our brains look like other animals, they have similar constitutions,
This is because were all related, due to a common evolution!
You are quite different though you see, from most animals it’s true,
The biggest difference has to do, with the brain inside of you!
Now go to bed my little child, your brain needs sleep to grow
And there’s so much more for you to learn, starting first thing tomorrow.