Video Time!!!
Here is a video which explains some things about your nervous system. Hope you will enjoy it :)
Wednesday 6 February 2013
Tuesday 5 February 2013
What is the nervous system?
The Nervous System
The nervous system is a complicated network of nerves and cells that carry
messages to and for from the brain and spinal cord to all the other parts of the body.
The nervous system includes:
1. Central nervous system --- made up of the brain and spinal cord
2. Peripheral nervous system --- made up of the Somatic and the Autonomic nervous systems
The Central Nervous System
The central nervous system is divided into two major parts, the brain
and the spinal cord.
The Brain
The brain lies within the skull and is shaped like a mushroom. The brain consists of four important parts, which are the brain stem, the cerebrum, the cerebellum and the diencephalon.
The brain has nerve cells called
the neurons.
The brain also has supporting cells called the glia.
There are two types of matter in the brain: grey matter and white matter.
Grey matter receives and stores
impulses. Cell bodies of neurons and
neuroglia are in the grey matter.
White
matter in the brain carries impulses to and from grey matter. It consists of the nerve fibers.
The Spinal Cord
The spinal cord is a long, tube-like structure which extends from the
brain downwards. The spinal cord is composed of a series of 31 segments. A pair of spinal nerves comes out of each
segment. The area of the spinal cord
from which a pair of spinal nerves originates is called the spinal
segment. Both motor and sensory nerves
are located in the spinal cord.
The spinal cord is about 43 cm long in adult women and 45 cm long in adult men.
It lies within the backbone.
The Peripheral Nervous System
The Peripheral nervous system is made up of two parts, the Somatic nervous system and the Autonomic nervous system.
Somatic Nervous System
The somatic nervous system consists of peripheral nerve fibres that
pick up sensory information or sensations from the peripheral or distant organs
and carry them to the central nervous
system.
These also consist of motor nerve fibres that come out of the brain and take the messages for movement and necessary action to the skeletal muscles.
For example, when you touch a hot object, the sensory nerves carry information
about the heat to the brain, which in turn, through the motor nerves, tells the
muscles of the hand to withdraw immediately.
The whole process takes less than a second to happen. The cell body of the neuron that carries the information often lies within the brain or spinal cord and projects directly to a skeletal muscle.
Autonomic Nervous System
The autonomic nervous system
has three parts, which are the sympathetic nervous system, the parasympathetic nervous system and the enteric nervous system.
This nervous system controls the nerves of the inner organs of the body in which humans have no conscious control. This includes the heartbeat, digestion, breathing, etc.
The nerves of the autonomic nervous system weaken the smooth involuntary muscles of the internal organs and glands and cause them to function well and secrete their enzymes.
The Enteric nervous system is the third part of the autonomic nervous system. The enteric nervous system is a complex network of nerve fibres that innervate the organs within the abdomen like the gastrointestinal tract, pancreas, gall bladder, etc. It contains nearly 100 million nerves.
Introduction
Hey everyone! We created this website to tell you more about the nervous system and how and why we do certain things. Hope you will enjoy all the information. :)
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