Unit 5-p3 the nervous system

The nervous system
The nervous system is made up of the brain, the spine and nerves. The nervous system is a complex
collection of nerves and specialised cells known as neurons that transmit signals between different
parts of the body. Structurally, the nervous system has two components, the central nervous system
and the peripheral nervous system. The central nervous system is made up of the brain, spinal cord
and nerves. The peripheral nervous system consists of sensory neurones, ganglia and nerves that
connect to one another and the central nervous system. Functionally, the nervous system has two
main subdivisions, the somatic or voluntary component and the autonomic or involuntary
component. The autonomic nervous system regulates certain body processes, such as blood
pressure and the rate of breathing. The somatic nervous system consists of nerves that connect the
brain and spinal cord with muscles and sensory receptors in the skin.
The main function in summary
The nervous system has three main functions, to collect sensory input from the body and external
environment. To process and interoperate the sensory input. To respond appropriately to the
sensory input.
After interoperating sensory input, the brain generates neural impulses that flow throughout the
nervous system to other parts of the body. The impulses, carried by motor neurons, allow us to
respond to the respond to the input from the environment. For example, if you touch a hot plate,
you reflexively pull back your hand and your nerves send pain signals to your brain alerting that you
are in pain and where the pain is.
The main components of the nervous system
The nervous system consists of the brain, the median nerve, the spinal cord, the thoracic nerves,
lumbar nerves, ulnar nerves, the tibial nerves, the radial nerve, the pudental nerve, the sacral nerve,
the sciatic nerve, and the saphenous nerve.
Brain
The brain, the computer of us all. The rest of the nervous system acts like a network, with the brain
being its controller. The brain is the centre of the nervous system, the brain controls what we think
and feel, how we learn and remember, and the way we move and talk. The rest of the nervous
system relays messages back and forth from the brain to different parts of the body, via the spine,
which runs down through the back.
In summary, the brains role in the nervous system is to control it and act as the system relaying
messages back and forth. Say for example you touch a hot pan, your nerves in the hand send a
message to the brain letting it know and the brain decides the response, which could be in a reflex
moving the hand away from the pan immediately.
Spinal cord
The spinal cord, is a thin long tubular structure composed of nervous tissue, extending from the
medulla in the brainstem to the vertebral column. The spinal cord plays an important role in the
nervous system as its acts as a highway for communication between the body and the brain. If for
example you feel pain in your foot as you stood on a pointy rock, the nerves in your foot will send a
message to the brain through the spinal cord to let it known pain was detected, which the brain may
respond by causing a reflex to pull your foot off the rock. In summary, the spinal cords main function
is to act as a passageways for nerves to send messages to the brain and for the brain to send
messages to the nerves.