A Rustling in the Bushes
It was late Friday night I was walking to a friend’s house when I heard a rustling in the bushes. I looked over, and in the shrubs I saw it—a rat. I can’t say I jumped. I can’t say I ran. It was like being zapped with an electric shock. I just found myself fifteen feet away with my heart pounding and blood racing.
What I experienced was the fight or flight response. When in danger, our bodies switch into emergency mode, and we get a surge of energy that allows us to perform feats of strength well beyond our normal limits. The stories are legendary. A fireman lifts a burning beam that supports an entire wall. A climber trapped under a 1200 lb. rock shoves it down an embankment. A mom lifts a car, freeing her trapped child. Feats of strength that under normal circumstances would be impossible.
While we recognize the adrenaline rush that brings on this state, the actual process is astonishingly complex. To appreciate it, let’s take a moment to look at the body.
The Human Body
On a mechanical level, the body is a set of interacting machines. Each organ is a part of a system; each system is linked to other systems. The heart is the pump, delivering nutrients to the cells. The liver is the food manufacturer, creating glucose—fuel to power the muscles. The kidneys are the filters, removing waste products. The lungs are the air movers, bringing in oxygen and transporting it to the blood. The muscles are the engines that do everything from aiding in digestion to lifting your arms, legs, head and chest.
Because each organ has a specific role, and functions in a particular manner, there must be over an overall guidance system to regulate it. For instance: The heart beats 100,00 times a day. What tells it how often to pump? How hard? And, at what rhythm? Glucose is a highly specialized chemical formula. What tells the liver the appropriate chemical composition? What tells it where to store the glucose? And how to release it? What tells the lungs how deeply to breathe and at what rate? What tells which muscles to squeeze and contract, and in what order, so that the diaphragm lifts and rises?
A specific area of the brain regulates each organ. Intricate nerve pathways signal the release of chemicals that causes chain reactions, which control the balance and function of each structure. The neuroscience and biochemistry of it fills libraries.
Systems Dependent Upon Systems
But things are a bit more complicated because; each system is dependent upon the correct functioning of other systems. The brain can’t operate unless the heart provides it with the precise measure of oxygen and compounds it requires, and the heart can’t function unless the lungs supply it with the exact mix of gases that it needs. The kidneys can’t filter, unless the liver supplies them with the perfect balance of fuel, and the liver can’t modulate that mix, if the digestive tract doesn’t break down all the nutrients into the component parts. (Kind of like, the hipbone connected to the thighbone, the thighbone connected to the knee bone…).
Each organ alone requires hundred of chemicals, and multiple chain reactions, to insure its proper functioning. Each chemical chain reaction is made up of dozens and dozens of steps, and cascades of chemical compounds. To keep all the systems and organs functioning in balance requires a processing center more complex than any computer man has every designed.
Understanding the Fight or Flight Response
Because the fight or flight response engages almost every organ and system in the body, the complexity of the operation is baffling.
At the first hint of danger, early warning signals are sent to the brain via the optic nerve to the fear center, the amygdala, which prepares the body for action. If the danger is confirmed, the disaster center in the brain jump-starts the body. Nerve impulses are fired down the spinal cord to the adrenal glands just above the kidneys. The glands flood the bloodstream with adrenaline, which boosts heart rate and blood pressure. Blood now races to the muscles. Adrenaline also signals the liver to flood the body with glucose. Blood is shunted away from the digestive tract and other non-life saving areas to allow for more to flow into critical areas. The lungs are signaled to breathe more quickly and deeply, injecting more oxygen into the blood. The metabolism is quickened. The senses are all on high alert. The mind is hyper-focused. The body is primed — ready to lift, run, or fight.
ATP – Emergency Fuel for Muscles
But this isn’t enough. In a life and death situation, milliseconds count. The body must respond immediately. What kickstarts the sprint to safety or the powerful lunge is instant energy stored in the muscles.
Long in advance of an emergency situation the body stockpiles energy—much like a high-energy battery—in the form of ATP – an energy molecule produced by burning glucose or fat. An emergency supply of ATP is housed in the muscles ready to turbo charge us on demand. For a few seconds, that energy burst can turn a middle aged man into an Olympic sprinter or a housewife into a power lifter. The supply only lasts about four seconds; then it is consumed. But during that time, we are able to perform superhuman feats of strength, pushing the body well beyond its limits.
The dazzling part is that it’s automatic. It usually happens before our conscious mind even recognizes the danger. One minute you might be calmly walking down the street, not thinking about much – then in an instant—the eyes see. The brain responds. And in a flash, mild-mannered Clark Kent is transformed into Superman. Ready to save the day.
But, there’s even more going on behind the scene.
Looking into Sight
If you think of an object – say a pen – your brain retrieves the object’s name, its shape, and its function. Each part of the memory of what a “pen” is comes from a different region of the brain. The entire image of “pen” is actively reconstructed by the brain from many different areas. Neurologists are only beginning to understand how the parts are reassembled into a coherent whole. But it is a fantastically complex process.
We normally think of our senses in simplistic terms. We see. We think. We hear. We feel. We taste. But what’s actually going on is far more involved. Our brain is taking in sensory input and processing it—making sense of what we are experiencing. To do that it decodes, assembles and then compares images that have accumulated over a lifetime. It then puts it all together into one composite, and brings us a coherent version of the world. The steps involved in the process are remarkable.
Let’s take vision for instance.
When I looked at the bushes and saw that rat, what actually happened was: First, I heard a rustling sound, and then turned my head to see what it was. The lens in my eye automatically adjusted to focus on an image. That image was projected onto the retina in the back of my eye. Cells in the retina converted that image into electrical impulses, which were sent along the optic nerve into my brain for decoding and deciphering. The question being: What is that object? Is it real? Is it a threat?
Then began the process of perception. Every second a billion items of information is sent through the eye. Initially, everything that enters is a blur, with an untold number of patches of light and dark, contours and lines. Information is then sent to different regions of the brain to piece together the images, refocus the eye for greater detail, and then interpret what it is that I am looking at. To do this, the supercomputer we call the brain must go into high gear.
The Visual Cortex
The first stop for this raw information is the thalamus, where the initial stages of recognition happen. Here the brain begins to collate and interpret the data, reaching some preliminary composites.
“Let’s see… That object is furry and has big ears and a tail. Hmmmmm… What could it be? Mickey Mouse has big ears and a tail… No, that can’t be it. Mickey isn’t furry. Well, a cat is furry and has a tail… No, a cat doesn’t have ears like that… Hmmmm. I wonder what this is?”
A signal is now sent to the visual cortex. “We need help identifying this. It’s clearly an animal, but what kind? Is it friendly or predatory?”
Signals are then relayed to the memory center to access previous visual images. Every image a person ever has ever seen is burned into a cell. These cells are inventoried by category, emotion and feelings. The catalogue of these cells is consulted to make a connection. Picture after picture is accessed until some recognitions form.
“Ah, look there’s my pet hamster. I owned him when I was ten. Nope, not him. What about this? It’s furry and has a tail. No, that’s a dog. Hey, what about this? Yeah, that looks right. I think that’s it. Yeah. But, hey, wait, that’s a… a… a…RAT!”
Since the visual image of a rat was stored with severe emotions attached, it comes back with a red flag, as in “Watch out! This might be dangerous!”
But not every rat is a threat. It depends on a number of factors. If I’m standing in the zoo, and the rat is behind a two inch thick piece of glass, I am not in harm’s way. So more information is needed.
Next, signals are sent to the Hippocampus to determine context. “Where am I? Where are they? Are they real?”
The answer comes back. “I am standing alone on a dark street late at night. Not good.”
Now the major number crunching part takes place—putting it all together. Each section of the brain fires off its conclusion. From the memory center comes the message: “Rat! Rat! Rat! This is not a drill! I repeat. This is not a drill”.
The context center relays the word, “We are in a situation – without backup”.
The thalamus then puts it all together. Rat. Night. Alone. TROUBLE! Immediate action is required!” It then shoots out a signal to the crisis center of the brain, “Warning! Warning! Red Alert. Danger”.
The Amygdala, the area that controls strong emotions is signaled. It flashes a message to the Hypothalamus, which then fires electrical impulses down the spine to the Adrenal Gland. Thirty hormones are released, sending commands to almost every system in the body. The heart and lungs are sent into overdrive. The brain is flooded with chemicals that focus attention. The pupils are dilated to allow in more light. The veins in the skin are constricted to force more blood to the muscles (Causing the familiar reaction of goose bumps). The immune and digestive system are shut down to allow more energy to the muscles. The liver secrets glucose and begins production of replenishments. ATP in the muscles is released—and the body is ready for peak performance.
From start to finish, how long does the process take?
About 0.3 seconds.
Roughly as much time as it took you to move from the end of the last sentence to the beginning of this one.
The point is that we are looking at a system of extreme complexity, more sophisticated than the finest machines, systems or factories man has ever conceived. But even at this level, we’re only scratching the surface of what is happening. To appreciate the complexity of this response, we need to take a further step back.
Ask a smart eight-year-old the following riddle. Here’s a choice: either I will give you a million dollars now, or I will give you a penny today, double it tomorrow, and keep doubling the amount you have each day for thirty days. Which would you chose?
Any self-respecting third grader would, of course, go for the million dollars. A million dollars is a huge sum!
But that third grader would have chosen poorly. If you take a penny and double it, then take those two pennies and double them, and keep doubling that amount, the base number that you are multiplying gets larger and larger so that the sum increases exponentially. And 2 to the 30th power equals 1.073 billion!
How the Brain Works
This concept is critical to understanding how the brain works. All brain activity is made up of neurons communicating with each other. A neuron is a tiny cell that acts both as a receiver and transmitter of messages. When a neuron receives a message, it passes it along to one of its neighbors via chemical signals. Those chemicals cause the next receiving neuron to fire off an electrical impulse. One neuron signals the next. That neuron then signals another. That one signals still another, and onwards until the final destination is reached. All communication is made up of transferring these signals from neuron to neuron along established pathways.
Here’s the interesting part. Each neuron has a number of endings through which it transmits and receives signals from its neighbors. It looks almost like a tadpole with tentacles or branches. Each transmitting neuron has many branches from which to send the signal, and each receiving neuron has many branches from which to receive it. Which branch receives the message makes all the difference in what the signal means, what part of the brain it will send it to next, and what it will do after that. And this is where things get complicated.
Since the transmitting neuron has many branches, it could send a signal through branch 1, 2, 3, 4, 5, or 6. Since, the receptor neuron, also, has many branches, it could receive the signal through branch, 14, 15, 16, 17, or 18. Since each neuron is in close proximity to many other neurons, it turns out that to get a signal from point A to point B, there are many, many paths that a signal could be sent on.
Let’s think about this. If the brain were made up of only thirty neurons, the possible pathways that a signal could follow would be countless. But the brain isn’t made up of thirty neurons. Every pinpoint of the visual cortex contains up to 30,000 neurons. Each of these neurons can communicate with up to 50,000 other neurons. So the possible pathways aren’t two to the 30th power. It is 30,000 to the 50,000th power. A number so large that is inconceivable.
But of course there’s more to the brain than the visual cortex—a lot more. There’s the amygdala, the hypothalamus, the hippocampus, the neocortex. The brain is made up of a hundred billion neurons, each with as many as fifty thousand connections. The math works out to be a hundred billion to the fiftieth power, a number so astronomical that it defies human comprehension.
Here is the question. How does the signal know to go from this neuron to that one? And from that one to that one? The possibilities are so vast, and the path so winding, convoluted and complex. How does it know to follow this particular intricate trail?
This question has baffled men of science for decades.
Why is this significant to us? Because by studying the creation, we can gain a glimpse to the Creator. When we contemplate such wisdom, we begin to get inkling to the sheer brilliance and capacity of Hashem.