Did you know there are more nerve cells inside in the human brain than stars in the Milky Way galaxy? As a matter of fact there are 100 billion nerve cells, so there is no denying that our brains are amazingly complex systems. The human nervous system includes the brain and spinal cord and is the information superhighway that allows us to interact with the environment and health and our physical environment around us. It controls all our biological processes as well as the movement in our bodies by interpreting information in the form of electrical signals. In short, it plays one of the most important roles to keep us functioning in our lives.
How Does the Nervous System Receive Information?
There are two parts of the entire human nervous system. The peripheral nervous system which sends and receives electrical impulses that transport information and the central nervous system or CNS which processes all the information that is received. Including both the brain and the spinal cord, the central nervous system must interpret all the signals it receives and then send out speedy responses and commands, either consciously or unconsciously, to all the other parts of our bodies.
Information primary travels from the sensory organs involved in sight, smell, and touch as well as from nerves that pass information through the spinal cord. The peripheral nervous system can sense information from both inside the body and outside it in our environment. This information is quickly sent through the complex system of the nervous system through the spinal cord until it reaches certain areas of the brain.
Nerve cells or neurons make up a large part of this information highway. Each neuron has a nucleus which has outgrowths called dendrites which reach out like fingers. The primary one has an axon which directly transmits electrical impulses as information throughout the nervous system to other parts of the body.
How Does Our Nervous System Communicate with Our Environment?
Like binary code or a light switch neurons use all-or-none communication to clearly transport messages. Messages need to travel quickly and a long distance through the body. Each message must travel as far as your finger or toe all the way to your brain and then back again. Since the nerve cells use all-or-none communications, the messages are very clear and there is little room to get it confused.
There are 43 main nerve branches that extend out from the central nervous system into the peripheral nervous system. In other words, 43 nerve systems connect our brains to the parts of our bodies that interact with our environment like our hands and feet. These information connectors are part of either the somatic nervous system or the autonomic nervous system.
The somatic nervous system controls the movement of our bodies that we can consciously decide to move with our thoughts. If you want to walk or throw a ball, you are utilizing your somatic nervous system. On the other hand, the autonomic nervous system controls the functions in our body like heartbeat and digestion which we do not have direct control over. The autonomic nervous system can be further divided into the sympathetic and parasympathetic nervous system which work as a checks and balance system to keep our vital functions running smoothly.
Fun Facts about the Human Nervous System
-Neurons have a nucleus, membrane, and mitochondria like other cells in our bodies. However, they have specialized projections called denrites and axons which respectively receive and send away information from the cell.
-The Human brain weights about 3 pounds or 1300 to 1400g. An elephant’s brain weights 6000g while a cat’s brain weighs only 30g.
-If you line up every neuron in your body in a straight line, the line would be 600 miles or 100km long!
-The average length of the spinal cord is 45 cm in men and 43 cm in women and weights only 35g (just a little more than a cat’s brain).
-Information travels at different speeds between different neurons. It can travel as slow as 0.5 meters/sec and all the way up to 120 meters/sec. If you convert it, 120m/s is the same as 268 miles per hour.
-Loss of sleep can cause you to lose brain cells.
-Drinking more alcohol than your body can process damages parts of the neurons that send and receive information. But it doesn’t kill them. However, some alcoholics can experience the loss of brain cells as a symptom of a disease called Wernicke-Korsakoff syndrome. Instead of the alcohol having the direct effect, malnutrition and lack of Vitamin B causes the decline in brain cells.