Our Marvelous Brain
The Scarecrow knew it.
He sang wistfully about how he’d while away the hours conferrin’ with the flowers, and his head he’d be scratchin’ while his thoughts were busy hatchin’.
If he only had a brain.
Lucky for us, we don’t have to wish for one. We’ve got a brain, and it’s a marvel of evolution.
It helps us reason, learn, remember, and think. It regulates the body, and allows us to see, taste, touch, smell, and hear.
But how much do you really know about it?
The Ancient History
Humans and our ancestors have been walking the planet for a long time, starting with Ardipithecus about six million years ago. Modern human beings — Homo sapiens — only appeared roughly 300,000 years ago.
But even our oldest ancestor is a baby compared to the brain itself, which can trace its origins back roughly 800 million years. At that time, simple creatures called eumetazoans lived in the seas and developed the first nerve cells.
Humble beginnings, yes. But things then started to move relatively quickly, at least from an evolutionary standpoint:
- The arrival of larger, more complex water animals led to the development of a brain structure called the cerebellum nearly 500 million years ago. It’s crucial for movement, muscle tone, and cognition (in addition to our ability to predict the future).
- The neocortex — unique to mammals — appeared somewhere around 250 million years ago. Its expansion is part of the reason why humans are capable of creativity, art, and sophisticated problem solving.
- The modern human brain arrived about 1.7 million years ago, more or less reached its present size 300,000 years ago, and has undergone advantageous change as recently as 60,000 years ago. The evidence suggests we are still evolving (although that is certainly slowing down).
- The modern brain has three main components: the cerebrum, the cerebellum, and the brain stem. Each of those are made up of several parts themselves.
The Modern Workhorse
The brain is a tireless workhorse.
It’s the central nervous system (CNS) Admiral that commands all of your body functions including breathing, temperature, personality, motor skills, sleep, emotion, thought, memory, hunger, your five senses, and virtually every other process that regulates and serves the body.
And that old adage that we use only 10% of our brain? Not true. We use it all (so you won’t develop superhuman abilities any time soon).
That takes a lot of energy. Despite weighing just over 3 pounds, the brain consumes about 20% of your blood and oxygen.
What’s more, the brain can produce about 23 watts of energy when it's fully awake. That’s enough to power a standard light bulb!
Impressive stuff, right?
Under the Hood
You’ve probably got a decent idea of what the brain looks like from books, television, and films.
But it’s not the whole picture.
Brains removed for research are treated to make them more stable. In its natural state, the human brain has the consistency of a stick of butter left on the kitchen counter.
And that’s not all you might not know. The brain is more than just the sum of its parts:
- The brain will triple in size during the first year of life.
- It contains more than 85 billion brain cells — called neurons — and each one is connected to anywhere from 1,000 to 10,000 other neurons.
- Your brain isn’t fully formed until you’re 25 years old. The frontal lobes — responsible for planning and reasoning — are the last to develop (remember that tidbit the next time you try to reason with a toddler).
- There are 100,000+ neurons and 1 billion synapses — the connections between brain cells — on a piece of brain tissue no bigger than a grain of sand.
- There are 100,000 miles of blood vessels in the brain.
- Information passes between neurons at a speed of up to 268mph.
- The brain is 60% fat.
- The spinal cord — the main communication highway between your brain and body — stops growing at around 4 years of age.
It packs a punch into a 3 pound blob, no?
More Fun Facts
You know it’s important. You know it’s the CPU of the body. You know it’s ground zero for everything that makes you, you.
But did you know this?
- Brain freeze is real. The technical term is sphenopalatine ganglioneuralgia. It occurs when cold causes a rapid dilation and contraction of arteries in the meninges, which covers the brain.
- The storage capacity of the human brain is virtually unlimited, containing up to one quadrillion connections between neurons. That's one followed by fifteen zeros!
- The brain begins to shrink as we age.
- The brain can not feel pain. Sure, it registers and interprets pain for every other part of the body, but the brain itself does not have any pain receptors. That’s why it’s possible to perform brain surgery on a patient who is fully awake and communicative.
- You can continue to make new neurons well into adulthood. Quality sleep, consistent exercise, and a healthy diet can contribute to this neurogenesis.
- Neuroplasticity is the brain’s ability to rewire and reorganize itself depending on need and necessity. One study found that parts of the brain normally used for processing visual information can rewire itself to process sound in visually-impaired individuals.
- Ever felt completely in sync with someone? You’re not alone. Research suggests that the brain waves of musicians can syncronize when playing music together.
- Different parts of your brain light up when reading silently than when reading out loud.
- There is evidence of successful brain surgery going back to the Stone Age (2.6 million years ago to roughly 3000 BCE).
- Headaches have little to do with your brain. They have more to do with a tightening of the meninges covering the brain, and the muscles and nerves of your neck.
- Removal of half of the brain — called a hemispherectomy — can occur with little or no impact on memory or personality.
As we've said, it’s a fascinating marvel of evolution.
And without it, who knows what we’d be?
Ultimately, the Scarecrow said it best:
And perhaps I'll deserve ya, and be even worthy 'erv ya, if I only had a brain.