Human Nervous System: Overview, Diagram, Importance, Functions

The nervous system also includes nerves, which are like little wires that send messages from the brain to the body and back. These messages help you do things like touch, see, hear, and move. Without the nervous system, your body wouldn't be able to work properly.

Human Nervous System Diagram

Central Nervous System

The Central Nervous System (CNS) is like the control center of your body. It includes the brain and the spinal cord. The brain is the boss, helping you think, learn, and remember things. It controls your movements, your senses (like sight and touch), and even your feelings. The spinal cord is a long, tube-like structure that connects the brain to the rest of the body. It sends messages back and forth between your brain and muscles. Together, the brain and spinal cord help you do everything from running and jumping to thinking and feeling. The CNS also helps you react to things quickly, like when you touch something hot and pull your hand away right away.

Brain

One of the most significant, largest, and central organs of the human neurological system is the brain. It is the neurological system's control unit, which aids in learning new things, remembering and comprehending information, making decisions, and much more. It is protected frontally, laterally, and dorsally by the skull, which encloses it. Three main components make up the human brain:

Forebrain : The anterior part of the brain consists of Cerebrum, Hypothalamus and Thalamus.

Midbrain : The smaller and central part of the brainstem consists of Tectum and Tegmentum.

Hindbrain : The central region of the brain, composed of Cerebellum, Medulla and Pons.

Spinal Cord

All bodily parts are connected to the brain by the spinal cord, a cylindrical bundle of nerve fibres and related tissues that is housed inside the spine. It extends back up and starts in the same direction as the medulla. It is encased in a bony cage known as the vertebral column and has meningeal membranes all around it. The transmission of nerve impulses to and from the brain, as well as spinal reflex actions, are the functions of the spinal cord.

Peripheral Nervous System

The lateral portion of the nervous system that emerges from the central nervous system and links various body regions to the central nervous system is known as the peripheral nervous system (PNS). Peripheral nerves enable us to perform both voluntary and involuntary movements. PNS includes two types of nerve fibers:

1. Afferent nerve fibers – These are responsible for transmitting messages from tissues and organs to the CNS.

2. Efferent nerve-fibers – These are responsible for conveying messages from CNS to the corresponding peripheral organ.

Classification of the peripheral nervous system:

Somatic neural system (SNS):

By sending impulses from the central nervous system to the skeletal muscle cells, the neural system regulates the body's voluntary movements. It is made up of somatic nerves.

Autonomic neural system (ANS):

Involuntary processes such as the control of physiological processes (digestion, breathing, salivation, etc.) are mediated by the autonomic nervous system. The CNS sends impulses to the smooth muscles and involuntary organs (heart, bladder, and pupil) through this self-regulating system. It is possible to further categorise the autonomic nervous system into:

• Sympathetic nervous system
• Parasympathetic nervous system

Neuron

A neuron is a well-organised and useful component of the nervous system. Unlike other cells, neurons may transmit electrochemical impulses and have irregular shapes. Below is a discussion of the various components of a neuron.

• The dendrite, the shortest fibre in the cell body, extends from the neuron's cell body.
• The axon, which is the longest thread on a neuron's cell body, is encased in a protective and insulating layer of myelin.
• The nucleus and cytoplasm make up the cell body.
• The small space that separates two neighboring neurons and allows nerve impulses to flow from one to the other is known as a synapse.

Nerves

The brain and spinal cord give rise to structures called nerves, which resemble threads. It is in charge of communicating with every bodily part. Nerves come in three different varieties. Some of these neurons are capable of firing messages at over 428 km/h or over 119 m/s.

1. Sensory nerves send messages from all the senses to the brain.
2. Motor nerves carry messages from the brain to all the muscles.
3. Mixed nerves carry both sensory and motor nerves.

Since cranial nerves convey impulses from the central nervous system, they originate in the brain. Some cranial nerves are classified as sensory nerves, while others are classified as mixed nerves. The spinal cord is the source of spinal nerves. All of the spinal nerves are mixed nerves that transmit and receive impulses from the central nervous system. The different nerves that emerge from different regions of the body are shown in the nervous system diagram above.

What is the importance of Human Nervous System?

The Nervous System is super important because it helps your body work properly. It sends messages between your brain, spinal cord, and other parts of your body. This lets you move, feel, think, and respond to the world around you. For example, when you touch something hot, your nervous system helps you quickly pull your hand away. It also helps you learn, remember things, and control your emotions. Without the nervous system, your body wouldn’t be able to communicate or do anything, making it a key part of staying healthy and active.

Functions of Human Nervous System

Here are the main functions of the Nervous System:

Controls Movement : Helps you move your muscles, like when you run, jump, or wave.

Senses the World : Lets you see, hear, taste, touch, and smell things around you.

Sends Messages : Carries signals between your brain and body to make sure everything works together.

Helps You Think : Allows you to think, learn, and remember things.

Regulates Emotions : Helps you feel happy, sad, or excited and understand your feelings.

Protects You : Helps you react quickly, like pulling away from something hot or sharp.