The nervous system is the body’s direct communication system. It’s made up of the body’s many nerve cells. These cells work together in a network that sends and receives signals from one part of the body to another.
Nerve cells take in information through the body’s senses: touch, taste, smell, sight, and sound. The brain interprets these sensory cues to understand what’s going on outside and inside the body.
This allows a person to use their body to interact with their surrounding environment and control their body functions.
The nervous system is very complex. We rely on it every day to help us stay healthy and safe. Why should we appreciate our nervous system? Read these 11 fun facts and you’ll know why:
1. The body has billions of nerve cells
Every person’s body contains billions of nerve cells (neurons). There are about 100 billion in the brain and 13.5 million in the spinal cord. The body’s neurons take up and send out electric and chemical signals to other neurons.
2. Neurons are made of three parts
Neurons receive signals in a short antennae-like part called the dendrite, and send signals to other neurons with a long cable-like part called the axon. Axons and dendrites vary in size, but axons are generally longer and sometimes an axon can be up to a meter long..
In some neurons, axons are covered with a thin layer of fat called myelin, which acts as an insulator. It helps transmit nerve signals, or impulses, down a long axon. All neurons have a cell body.
The cell body contains important structures, such as the genetic information, energy producing structures, and more.
3. Neurons may look different from one another
Neurons come in a variety of shapes and sizes depending on where they’re located in the body and what they’re programmed to do.
Most neurons have several axons and dendrites, and the position of the cell body and the length and numbers of the axons and dendrites can vary.
4. Neurons are programmed to do different things
There are four types of neurons:
- Sensory: Sensory neurons deliver electrical signals from glands, muscles, and skin into the CNS.
- Motor: Motor neurons carry signals from the CNS to the muscles.
- Interneurons: Interneurons sends messages between neurons.
5. There are two parts of the nervous system
The human nervous system is defined as two parts. They are the central nervous system (CNS) and the peripheral nervous system (PNS).
The CNS is located in the skull and vertebral canal of the spine. It includes the nerves in the brain and spinal cord. The sensory and motor nerves that run through the extremities and internal organs are defined as the PNS.
6. There are two types of nervous systems
Everyone’s body has a CNS and a PNS. And the CNS and PNS control voluntary and involuntary functions. The body’s voluntary (somatic) nervous system controls things a person is aware of and can control consciously, such as moving their head, arms, legs, or other body parts.
The body’s involuntary (autonomic) nervous system controls processes in the body that a person doesn’t consciously control. It’s always active and regulates a person’s heart rate, breathing, metabolism, among other critical body processes.
7. The involuntary system is broken down into three parts
The involuntary part of the PNS includes the sympathetic, parasympathetic, and enteric nervous systems. The sympathetic, parasympathetic, and enteric nervous system work together to balance out your body’s functions.
Usually, the parasympathetic nervous system hormones promote relaxation, learning, and sleep.
Your sympathetic nervous system hormones temporarily increase your ability to manage urgent matters and exert intense physical effort.
The enteric nervous system controls your digestive system, and it is regulated by the sympathetic and parasympathetic nervous system.
8. The body has a nervous system for preparing the body for action
The sympathetic nervous system tells the body to get ready for physical and mental activity. It causes the heart to beat harder and faster and opens the airways for easy breathing. It also temporarily slows digestion so the body can focus on fast action.
9. There is a nervous system for controlling the body at rest
The parasympathetic nervous system promotes a resting state. Some of its activities include stimulating digestion, activating metabolism, and helping the body relax.
10. There is a nervous system for controlling the bowel
The enteric nervous system is composed of nerves that are embedded in the organs of the digestive system, which control breakdown of food, absorption of nutrients, and elimination of waste. These actions are regulated by hormones of the parasympathetic and sympathetic nervous system.
11. Your nervous system can be hacked
Hacking can help scientists learn about the functions of different groups of neurons. They can activate several brain cells at the same time and observe their effects on the body.
