How Does the Nervous System Work in the Human Body?
The Nervous system, a coordinated group of cells that are specialized in conducting electrochemical stimuli from sensory receptors through a network to the location where a reaction is taking place.
Parts of Nervous System
The nervous system is composed of the peripheral nervous system and the central nervous system:
Central Nervous System - includes brain and the spinal cord
Peripheral Nervous System - includes nerves that go through the whole body.
The human brain is extremely compact and only weighs 3 pounds. However, it does have many folds and grooves. These offer it the additional surface area required to store important information about the body.
The spinal cord is a long bundle of about 18 inches long and 1/2-inch-thick nerve tissue. It travels through the spine from the lower part of the brain downwards. Nerves branch out towards the entire body along the way.
Both the brain and the spinal cord are protected by the bone: the brain is protected by the skull bones, and the spinal cord is protected by a set of rings - shaped bones called vertebras. Both are cushioned by membrane layers called meninges, and a special fluid called the cerebrospinal fluid. This fluid assists in preserving the nerve tissue, keeping it healthy, and eliminating waste products.
In this article, some of the human nervous system facts are discussed
10 Interesting Facts About the Nervous System
Fact - 1
There are over millions of nerve cells in our central nervous system, 100 billion neurons in the human brain and around 13,500,000 neurons in the spinal cord.
Fact - 2
Sciatic nerve is the longest and broadest single nerve in the human body. It starts or originates from the lower back of the spine and runs through the buttock and down to the lower limb till the toe. The sciatic nerve works by providing sensation to the skin of the foot 's sole, lower leg and upper surface.
Fact - 3
Vitamin-B, sodium, proteins, and other mineral ions, including potassium, magnesium, and calcium ions, are equally essential nutrients needed to keep our nervous system healthy and functioning properly.
Fact - 4
Nerve damage is usually permanent and can cause any nerves in the body to lose control. This is because the nerve cells do not undergo the cell division process, and thus they cannot expand or rebuild themselves.
Fact - 5
An optic nerve, also known as the cranial nerve, is the fundamental part of the central nervous system, and the human eye's most significant sensory nerve. The eye structure comprises mainly millions to billions of optic nerve fibers and is involved in the transmission of visual information from the eye to the brain.
Fact - 6
The nervous system is our body's primary control system as it is involved in all functions, from respiring, generating and receiving responses, controlling the muscles and sensing heat , cold and much more.
Fact - 7
Other systems can act as a damage to the nervous system. For the human body, the nervous system is essential as it provides the ability to interact with the world.
Fact - 8
Alpha motor neurons are the speediest signal transmission in the human body. It is the biggest, multipolar lower brainstem and spinal cord motor neurons. Transmission of the signal occurs at 260 to 268 miles per hour.
Fact - 9
The slowest signal transmission occurs inside the skin of the human body.
Fact - 10
As we grow older the human nervous system begins to shrink. The human brain often shrinks with an individual's age, which each year shrinks by about 1 to 2 grams and is mainly caused by neuron loss.
Thus these are some of the nervous system facts.
FAQs on Nervous System Facts Every Biology Student Should Know
1. What is the nervous system and what are its primary functions?
The nervous system is the body's highly complex command and communication network. It is responsible for coordinating actions and transmitting signals between different parts of the body. Its three primary functions are:
- Sensory Input: Gathering information from sensory receptors that monitor changes both inside and outside the body.
- Integration: Processing and interpreting the sensory input to decide what action should be taken.
- Motor Output: Activating effector organs, like muscles and glands, to cause a response.
2. What are the two main divisions of the human nervous system?
The human nervous system is structurally divided into two main parts:
- The Central Nervous System (CNS), which consists of the brain and the spinal cord. It acts as the primary control centre, processing information and making decisions.
- The Peripheral Nervous System (PNS), which includes all the nerves that branch out from the brain and spinal cord to connect the CNS to the rest of the body, including limbs and organs.
3. What are some interesting facts about the nervous system?
The nervous system has many fascinating characteristics. Here are a few key facts:
- The human brain contains approximately 86 billion neurons.
- Nerve impulses can travel at speeds of up to 120 meters per second.
- The right side of your brain controls the left side of your body, and the left side of your brain controls the right side.
- Despite making up only 2% of the body's weight, the brain uses about 20% of the body's oxygen and calories.
4. How do neurons transmit signals throughout the body?
Neurons transmit signals using a combination of electrical and chemical processes. A signal, or impulse, is received by the neuron's dendrites and travels down the axon as an electrical charge called an action potential. When this electrical impulse reaches the end of the axon, it triggers the release of chemical messengers called neurotransmitters into a tiny gap known as the synapse. These neurotransmitters then bind to the next neuron, passing the signal along.
5. Why is the nervous system considered the body's master control system?
The nervous system is considered the master control system because it regulates and coordinates virtually all body functions. It controls everything from involuntary actions essential for survival, such as breathing and heartbeat, to complex voluntary actions like walking and speaking. Furthermore, it is the seat of all higher-order functions, including thought, learning, memory, and emotion, making it fundamental to our existence and interaction with the world.
6. What is the main difference between a reflex action and a conscious action?
The key difference lies in the processing pathway and speed. A reflex action is an extremely rapid, involuntary response to a stimulus, primarily processed by the spinal cord to ensure immediate protection (e.g., pulling your hand away from a hot surface). A conscious action, in contrast, is a voluntary response that involves thought and decision-making processed by the brain, making it a much slower and more deliberate process.
7. Can the nervous system repair itself after being damaged?
The ability of the nervous system to repair itself varies significantly between its two main parts. Nerves in the Peripheral Nervous System (PNS) have a limited but notable capacity to regenerate after injury, provided the neuron's cell body remains intact. However, neurons in the Central Nervous System (CNS)—the brain and spinal cord—have a very limited ability to repair or regenerate. This is why injuries to the CNS, such as spinal cord damage, often result in permanent functional loss.
