Structure and Functions of the Nervous System in Humans
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 Facts About the Human Nervous System Explained
1. What is the nervous system?
The nervous system is the body’s control and communication system that transmits signals between different parts of the body using electrical and chemical impulses. It allows the body to sense, process, and respond to internal and external stimuli.
- It consists of the central nervous system (CNS) and peripheral nervous system (PNS).
- It controls voluntary actions like movement and involuntary actions like breathing.
- It helps maintain coordination, memory, thinking, and homeostasis.
2. What are the main parts of the nervous system?
The nervous system has two main parts: the central nervous system and the peripheral nervous system. These parts work together to process and transmit information.
- CNS: Includes the brain and spinal cord; processes and interprets information.
- PNS: Includes all nerves outside the CNS; carries signals to and from the CNS.
- The PNS is further divided into the somatic and autonomic nervous systems.
3. What is the function of the nervous system?
The main function of the nervous system is to receive sensory input, process information, and produce appropriate responses. It ensures coordination and control of body activities.
- Sensory function: Detects stimuli through receptors.
- Integrative function: Processes and interprets sensory information in the CNS.
- Motor function: Sends signals to muscles and glands to respond.
4. What is a neuron and what does it do?
A neuron is a specialized nerve cell that transmits electrical impulses throughout the nervous system. It is the structural and functional unit of the nervous system.
- It consists of dendrites, a cell body, and an axon.
- Dendrites receive signals from other cells.
- The axon carries impulses away from the cell body.
5. How does a nerve impulse travel through a neuron?
A nerve impulse travels along a neuron as an electrical signal called an action potential. This signal moves in one direction from dendrites to axon terminals.
- Stimulus triggers depolarization of the neuron membrane.
- The action potential travels along the axon.
- At the axon terminal, neurotransmitters are released across the synapse.
6. What is the difference between the central and peripheral nervous system?
The central nervous system processes information, while the peripheral nervous system transmits signals between the CNS and the rest of the body. Both systems are essential for coordination.
- CNS: Includes brain and spinal cord; acts as the control center.
- PNS: Includes cranial and spinal nerves; connects limbs and organs to the CNS.
- The PNS enables communication between the body and brain.
7. What is a reflex action in the nervous system?
A reflex action is a rapid, automatic response to a stimulus that occurs without conscious control. It helps protect the body from harm.
- It involves a reflex arc.
- Pathway: receptor → sensory neuron → spinal cord → motor neuron → effector.
- Example: withdrawing your hand from a hot object.
8. What are the types of neurons?
There are three main types of neurons: sensory, motor, and interneurons. Each type has a specific role in signal transmission.
- Sensory neurons: Carry impulses from receptors to the CNS.
- Motor neurons: Carry impulses from the CNS to muscles or glands.
- Interneurons: Connect sensory and motor neurons within the CNS.
9. What is the autonomic nervous system and what does it control?
The autonomic nervous system (ANS) controls involuntary body functions such as heartbeat, digestion, and breathing. It operates without conscious effort.
- Divided into sympathetic and parasympathetic divisions.
- Sympathetic: Prepares the body for "fight or flight".
- Parasympathetic: Promotes "rest and digest" activities.
10. Why is the nervous system important for the human body?
The nervous system is important because it coordinates body activities, enables thinking and memory, and helps maintain internal balance. Without it, communication between organs would not occur.
- Controls movement and posture.
- Regulates vital functions like breathing and heart rate.
- Enables learning, emotions, and decision-making.
