The human body is constantly using electric signals to communicate, move & think. The communication occurs as signals in the nervous system. Our whole bodies are using e-impulses, which can travel up to 120 meters per second. But unlike our power networks and electricity at home, which work with free electrons, electricity in our bodies comes from charged chemical signals which lets our human cells use that power.
Electrical signals can be generated from your brain, where they travel to different areas of your body – or it can work the other way around. You can dip your toes into water, and even if your eyes are closed, your brain will understand what’s happening, because those sensory signals traveled through your body. But the body likes to use multiple senses together, so that you’re not fooled. Think about those children’s games at Halloween, where your friend’s mom tells you that you’re touching slimy eyeballs – but it’s really peeled grapes.
These signals travel from wherever they are produced, through the body by way of the cells with the help of the axons, which are a part of the neuron that transmits signals, like wires from the cell body to the next neuron. These signals flow through the nervous system in the body, using a system of chemical neurotransmitters, which are created by neurons. Neuron is another word for nerve cell and these cells can communicate with each other through connections called synapses.
There are different types of neurons like sensory neurons, motor neurons, interneurons – but when they group together they can form a neural circuit. Individually, they are made up of different parts, called soma (the cell body), dendrites and an axon. And as previously mentioned, they send signals to one another through both electrical and chemical processes. Sodium and potassium ions move in and out of the cell, across the membranes, which causes the electrical signal to increase and the neurons to fire.
The brain has around 86 billion neurons, which are interconnected by around a quadrillion synapses. Those are some big numbers! Although we’ve said that the electrical systems in the body are different from our own distribution networks, they do share one thing in common. To produce energy, you need a fuel source.
Of course, we love electrons produced with green, renewable energy, but the electricity that is delivered to industry and to our homes can also be produced by sources such as natural gas, oil, coal or even nuclear fusion. But the brain doesn’t go for any of this, and instead produces its internal power from glucose.
Other organs in your body require different types of fuel, but the brain really wants glucose and consumes around 120 g daily. Glucose is nothing more than a simple sugar. It falls into the category of monosaccharides and is naturally occurring in such foods as fruits and honey. It can also be converted by the liver from other types of sugars.
Turns out that your heart also needs a little electrical power to keep itself beating. Electrical stimuli are generated in the sinus node of the heart, in the upper chamber. Depending on your size, age and fitness level, the heart will produce this electrical stimulus between 60-100 times per minute. This then travels through the pathways of the organ, helping the heart to contract, which enables it to act as a pump for the blood in our circulatory system.
We can measure this activity through an electrocardiogram, or ECG. Turns out, that it’s a bit too complicated to put sensors on the heart itself, so we measure the surface potential or the electrical signal on the body instead. Sensors are normally placed in a triangular area directly on the torso and measurements are made over time. Based on how the signals look, different problems can be detected, such as a heart attack or irregular heartbeats.
A similar system can be used on the brain with an electroencephalogram, or EEG. Again, it’s not very convenient to hook up detectors directly to the brain, so sensors are placed all over the scalp. Typical amplitudes of brain signals from the scalp are 30-50 micro Volts. Problems such as epilepsy can be determined by the unique signals recorded through this method.
For sure, many textbooks are filled with a lot more information on the specifics of electrical forces in the human body. And certainly, a lot of other living things share these types of systems with us, so that there are a lot of electric creatures roaming our lovely planet. But it’s exciting to think about how many wonderful & complicated things are going on within our own bodies.