The spinal cord and nerves
The spinal cord has two main types of tissue; the grey matter which contains the nerve cell bodies and all of the connections between nerves. The white matter which is like a free way made up of nerve axon fibres from the spine to the brain (Filler, 2004). Nerves divide off many times as they leave the spinal cord so that they can reach all parts of the body, the thickest nerve is around an inch thick and the thinnest is thinner than a human hair. Each nerve is a bundle of neurons which is a nerve cell and there and hundreds of these which make up a nerve. The spinal cord goes down what looks like a tunnel of holes in the spine. The bones protect the nerves from getting damaged. The cord is a big bundle of nerves that connect the brain to the rest of the body. The spinal cord has two functions, one is to connect the larger part of the peripheral nervous system to the brain. Nerve impulses are sent through the spinal cord through sensory neurons and are sent up into the brain. The second thing that the spinal cord is used fir is that it acts as a coordinator and this causes reflexes. The main function of the nerve cells is to communication around the body, this happens by electrical and chemical messages between neurons. Sensory nerve ending are called sensory receptors and they receive information inside a sense organ, an example of this are eyes, ears, skin, etc, and the sensory nerves send this information to the central nervous system. Motor nerves send messages from the central nervous system to skeletal muscle, muscles that control speech, internal organs, internal glands and sweat glands in the skin to bring a reaction. This information is then sent through nerves from the central nervous system to the rest of the body. The motor nerves are split into two, somatic and autonomic. The somatic nervous system send messages for potential actions to the skeletal muscles which are under voluntary control. The autonomic nervous system sends messaged for potential actions from the central nervous system to smooth muscle, cardiac muscle and certain glands.
One dysfunction of the nervous system is Dementia. This is when the body stops all areas of mental ability. The cause is usually brain disease and doesn't get better once it starts because the cells in the brain have died however there are causes that can be reversed and memory brought back to its usual state, this is if it is caused by depression, drug intake, thyroid problems, a lot of alcohol intake or certain vitamin deficiencies. The most common way to spot dementia is a loss of intellectuality It is mostly caused from cerebro-vascular diseases such as alzheimer's disease. cerebro-vascular diseases are often caused by the arteries in the brain becoming narrower or blocked. When dementia occurs there is a loss of:
- thinking
- language
- understanding
- judgement
There is cure for dementia however there is medication to help the cognitive and medication symptoms. Dementia is caused when there is an interruption in the blood supply to the brain. This interruption to blood supply can happen gradually over a long period of time if the vessels inside the brain narrow and harden. This narrowing and hardening of the blood vessels is usually caused when fatty deposits build up on the blood vessels, stopping or slowing the flow of blood this is called atherosclerosis. A person that has dementia will usually receive care from many different people across the NHS and social care.
Another dysfunction is Multiple sclerosis (MS) and this is a condition that affects women more than men and is one of the most common neurological condition in young adults that are in the UK affecting more than 100,000 people. The 3 main types or MS are:
- relapsing remitting MS
- secondary progressive MS
- primary progressive MS
MS is a condition that affects the central nervous system (the brain and spinal cord). Each nerve fibre in the central nervous system is surrounded by a substance called myelin. Myelin helps messages from the brain to travel quickly and smoothly to the rest of the body. When somebody has MS, the myelin becomes damaged. This stops or slows down the transfer of these messages. MS can affect anybody at any age but symptoms are mostly seen first at people aged 20 to 40. Once MS has developed in somebody it is a lifelong condition but not terminal, most people that have MS can live up to the age of somebody that doesn't have it however around 20% of the people with MS do have a shortened life. There are many different symptoms of MS and they affect each person differently. Some of the most common symptoms are:
- numbness and tingling
- blurring of vision
- problems with mobility and balance
- muscle weakness and tightness
a lot of people that have MS only have a few of these symptoms and it is unlikely that someone would develop all of the symptoms at the same time. MS is an autoimmune condition which means that the immune system confuses the myelin for a foreign substance and attacks it. The myelin then becomes inflamed in small patches (called lesions) which are seen on an MRI scan. This is called demyelination. Demyelination confuses or stops the messages travelling along nerve fibres. It can slow them down and mix them or accidentally send them down a different nerve fibre or stop them from getting through at all. There is no cure for MS however there are many treatments that can relieve the symptoms and relapses that may slow the progression of MS.
The final dysfunction is Parkinson's disease and this is a long-term neurological condition that affects around 120,000 people in the UK. Parkinson's disease affects the way the brain co-ordinates body movements and this includes walking, talking and writing. It affects both men and women, but men are slightly more likely to develop it than women. It is usually first diagnosed at around the age of 50. The symptoms of Parkinson's disease usually begin slowly and develop gradually, the symptoms are slowness of movement, trembling and shaking and stiffness of muscles. Parkinson's disease is usually caused by a loss of nerve cells in the part of the brain called the substantia nigra. The nerve cells in this part of the brain are responsible for producing a chemical called dopamine and opamine acts as a messenger between the brain and the nervous system and this helps control and co-ordinate our body movements. If the nerve cells become damaged or die, the amount of dopamine in the brain is shortened. This means that the part of the brain that controls movement cannot work as good as it should which causes body movements to become slow. The loss of nerve cells is a slow process. The level of dopamine in the brain lessens over time. Parkinson's disease symptoms will only show when around 80% of the nerve cells have died. The National Institute for Health and Clinical Excellence (NICE) guideline states that if you have Parkinson’s disease, a healthcare professional like a Parkinson’s disease specialist nurse should provide the service user with help, they should:
- regularly check how their medicines are making them feel and make changes to their medication if necessary
- be a point of contact and support for their family or carers, and go to see them at their home when appropriate
- give them reliable information about Parkinson’s disease, its symptoms and treatments, and the wider issues that can affect people with the disease and their family or carers
Bibliography
Filler, A. (June 2007) Do You Really Need Back Surgery: A Surgeon's Guide to Neck and Back Pain and How to Choose Your Treatment
[Online]
[Accessed] 18/05/2011