1. The nervous system has two main parts
Most animals have a nervous system that contains two parts namely the central and the peripheral. The central nervous system in vertebrates contains the brain, spinal cord, and retina. The peripheral nervous system consists of the sensory neurons, ganglia and nerves connecting to each other and the central nervous system.
2. The main work of a nervous system is to send signals
The primary function of the nervous system is to send signals from one part of the body to another or from one cell to the other. There are two main sub-divisions of the nervous system; the voluntary or somatic component, and the involuntary or autonomic component. The involuntary nervous system regulates certain body processes such as blood pressure and the rate of breathing. These are processes that work without conscious effort. The voluntary system consists of nerves that connect the brain and spinal cord with muscles and sensory receptors in the skin.
3. The nervous system needs nutrients to operate well
The nervous system requires specific nutrients to operate properly. Nutrients such as sodium ions, vitamin B, and potassium ensure the proper functioning of the nervous system.
4. The nervous system is comprised of neurons and glial cells
The nervous system is made up of neurons and glial cells. Neurons send signals to other cells in the form of electrochemical waves. They communicate with other cells via synapses. They are specialized cells that give structure and support to neurons. Glial cells on the other hand help hold neurons in place, supply nutrients to neurons, destroy germs, remove dead neurons, and direct axons of neurons.
5. The nervous system sends signals at extremely high speeds
The speed at which the nervous system sends signals is extremely high. The nervous system can transfer signals at speeds of 100 meters (328 feet) per second. There are approximately 100 billion neurons in the human brain and 13.5 million neurons in the human spinal cord. The entire surface area of the human brain is about 25, 000 square cm. At any given point in time, the brain has only four percent of its cells active, while the rest are kept in reserve. An average adult male brain weighs approximately 1375 grams. An average adult female brain is about 1275 grams.
6. Pain is the most difficult illness that affects the nervous system
Of all the illnesses that affect the nervous system, the most common difficult one that people suffer from is pain. This is mostly related to the nerves. An estimated 100 million people live with chronic pain that affects the nervous system.
7. Earthworms have a dual nervous system
Earthworms contain dual nerve cords running along the length of the body. These nerve cords converge at the tail and the mouth of these creatures.
8. Control of the nervous system happens in the opposite sides
In human beings, control of the nervous system tends to happen in the opposite side. The right side of the human brain controls the left side of the body, and the left side of the human brain controls the right side of the body.
9. Newborns lose 50% of nerve cells before birth
A newborns loss approximately half of the nerve cells before they are born. As human beings age, the brain loses nearly one gram of its weight each year.
10. The nervous system responds to fear
The human reaction to touch, danger and fear is very fast. The electrical signals in the nerve fibers travel very fast, around 280 kilometers per hour and even higher to send impulses to the brain. The brain sends back a message telling one to react in such ways as duck, hide, or run in dangerous scenarios.