If I had to pick a favorite, nervous tissue would be my choice. Often underestimated and ignored in the world of sport and fitness, it’s that unassuming nervous tissue that controls everything you do, everything you are, and everything you perceive. It’s pretty powerful stuff, really.

Your body is riddled with nerve endings, each with the purpose of receiving information or giving instruction to other tissues. Through a series of chemical reactions information is received and converted into nerve action impulses, much like electrical signals. These electrical signals are sent to and through the spinal cord, and then to the brain. If the information is perceived as urgent by the spinal cord, the spinal cord sends immediate instructions back to the tissues before the nerve action potential reaches the brain for actual interpretation. This is when reflexes occur. We’ve all seen tests where doctors tap on a person’s knee and the foot shoots forward, seemingly spontaneously, and definitely without thought, consideration or conscious effort from the patient. This is also true in cases where a person may place their hand in a hot flame or on a burner. Most often, this person will pull the hand away from the noxious or painful stimulus before any pain has actually been felt. The throbbing or burning, or even grasping of the now wounded limb occurs moments later. Consider a time in your life where you’ve stubbed your toe, grabbed it and only after, felt the throbbing pain. It takes more time for the action potential to reach the brain, which is further away from the original input, than the spinal cord. It then takes time for the brain to interpret the input, and send that interpretation to another very specific area of your brain (the cerebral cortex) in order for you to actually perceive it. Once interpretation has taken place, the nervous tissue that is your brain will also then send output through the spinal cord, and along nerves, telling the rest of your body how to respond to the original input.

The nervous system is complex, to say the least.

In a very similar manner as to how input is received, instructions are given to other tissues through a series of chemical reactions that result in the release specific chemicals that causes a reaction in other tissues. For example, at a neuromuscular junction (the place where nervous tissue meets muscular tissue), a chemical neurotransmitter called acetylcholine (Ach) is released. On contact with the muscle tissue, acetylcholine binds to receptors that cause a reaction in the muscular tissue called depolarization. This is what results in muscle contraction. Nervous activity is responsible for resting muscle tone as well. The absence of acetylcholine, or the absence acetylcholine receptors on muscle cells, results in flaccid muscles.

 

Nervous tissue controls everything. And like all tissue in the human body, it’s smart. If you aren’t using it, your body is not going to waste energy maintaining or growing it. Ever walk into a gym and pick up a relatively large weight and it felt impossible at first? So you lower the weight, do a few reps, warming up your tissues before giving the large weight another go, and it’s suddenly not only doable, but much, much easier? This warming up routine is actually awakening more nerve endings which means more acetylcholine is released at the neuromuscular junction, causing stronger contractions with less perceived effort. The more nerve endings that are firing or releasing acetylcholine at the neuromuscular junction, the stronger the muscle contraction will be. You didn’t actually get stronger in the 10 minutes it took you to warm up – you just better prepared your body to do that exercise! Essentially a warm up is nothing more than a nervous tissue wake up. Though if you get your heart beating and your circulation pumping at the same time, you’re likely to get actually warm too!

Nervous tissue is responsible for far more than just muscle contraction or resting muscle tone. Nervous tissue is responsible for all of your sensations. Consider the mechanism of how we smell things. Little particles of whatever it is are sucked in through our nose as we breathe in. At the very top of our nose is a bony plate with bulb of nervous tissues on top of it called the ‘olfactory bulb’. The olfactory bulb projects nerve endings through the bony plate at acts as the roof of the nose. These nerve endings allow for those little molecules of odorants to attach to them, stimulating an action potential. The action potential is sent to the brain where the brain interprets the chemical signals and informs your cerebral cortex of what it is you smell. On a fascinating side note, have you ever noticed how certain smells bring back certain memories? This is because the area in your brain that interprets smell is nestled right next to, possibly even sharing some of the same neurons that your memories are stored in. There is a very strong connection between smell and memory for most people.

You also see things in a similar manner to which you smell or feel things. Nerve endings on your retina allow light to bounce of them. This light bouncing causes the nerve ending to send an action potential along the neuron to your brain for interpretation, this interpretation is sent to your cerebral cortex for you to receive cognitive perception of what you see.

You have very specific nerves that are proprioceptive in nature, which means they are giving feedback to your brain as to the position and movement of your body at any given time. Proprioception is why you can, or cannot (especially if you’ve had a drink or two) close your eyes and stand on one leg, or touch your finger to your nose. Like warming up or waking up nerves to cause muscle contraction, you can and should train proprioception. This is what balance exercises are all about, or what elite training for peak performance in any sport or fitness focuses on. Proprioceptive training is the tweaks of performance towards perfection. A lot of gymnastics techniques for example, are impossible for the average person no matter how strong their muscles are, because they haven’t undergone the extensive proprioceptive training practice that most gymnasts do.

Everything you perceive, everything you are is because of your nervous tissue. In many ways then, no matter what it is, it’s all in your head. Thinking, also occurring via nerve impulses is also in your head.  This is just one of the reasons why thinking positive is scientifically important for your mind and body!