Nervous system parts and functions

Nervous system diagram
Nervous system organs
Central nervous system

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The nervous system helps all the parts of the body to communicate with each other. It also reacts to changes both outside and inside the body. The nervous system uses both electrical and chemical means to send and receive messages.

Neurones are the building blocks

The basic building block of the nervous system is a nerve cell, or neurone. Neurones are shaped differently depending on where they are in the body and what role they play. All neurones have finger-like projections called dendrites and a long fibre called an axon.

In many cases, the axon is coated by a specialised membrane called a myelin sheath. The axon feathers out and has a number of bumps on it. Each bump sits near to a dendrite from another neurone. The space between the bump and the dendrite is called a synapse. Messages jump the synapse from one neurone to the next, using special chemicals called neurotransmitters.

Unlike other cells in the body, neurones aren’t easily replaced if they die or are damaged by infection or injury.

Central nervous system

The brain and the spinal cord make up the central nervo

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Structure and Function of the Central Nervous System

The central nervous system (CNS) is comprised of the brain and spinal cord. The three broad functions of the CNS are to take in sensory information, process information, and send out motor signals.

The CNS receives sensory information from the nervous system and controls the body's responses. The central nervous system plays a primary role in receiving information from various areas of the body and then coordinating this activity to produce the body's responses.

The CNS is differentiated from the peripheral nervous system, which involves all of the nerves outside of the brain and spinal cord that carry messages to the CNS.

This article discusses the structures that make up the central nervous system and how they function. It also explores some of the diseases and conditions that can affect the CNS.

Central Nervous System Structure

The CNS has three main components: the brain, the spinal cord, and the neurons (or nerve cells). Each part of the CNS plays an important role in how the body functions, and th

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Nervous system

Part of an animal that coordinates actions and senses

For other uses, see Nervous system (disambiguation).

In biology, the nervous system is the highly complex part of an animal that coordinates its actions and sensory information by transmitting signals to and from different parts of its body. The nervous system detects environmental changes that impact the body, then works in tandem with the endocrine system to respond to such events.^[1] Nervous tissue first arose in wormlike organisms about 550 to 600 million years ago. In vertebrates, it consists of two main parts, the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS consists of the brain and spinal cord. The PNS consists mainly of nerves, which are enclosed bundles of the long fibers, or axons, that connect the CNS to every other part of the body. Nerves that transmit signals from the brain are called motor nerves (efferent), while those nerves that transmit information from the body to the CNS are called sensory nerves (afferent). The PNS is divided into two separa