Todays topic for biology class 12 is Diseases of Nervous System.Nervous system is one of the eight organ systems of the body. It consists of the brain, spinal cord and nerves.
Some of the diseases associated with the nervous system are -
1. Poliomyelitis - It is a type of acute viral infection due to which the cell bodies of motor neurons are destroyed that are present in the anterior horn of spinal cord.The respiratory centres in medulla oblongata and motor neurons in brain stem are affected by bulbar poliomyelitis. Some of the symptoms of this disease are -
1. muscle pain
2. stiffness in neck
3. headache
4. fever
The motor nerves that are served by the dying neurons become paralysed. The sensory functions of the paralysed limbs is not effected. Sometimes, with the help of physiotherapy, partial or even total function of the limbs can be regained.
2. Meningitis - The inflammation of meninges is known as meningitis which is caused by infectious organisms such as bacteria, viruses etc. Bacteria infections can be controlled by antibiotics but viral infections have no effective treatment. It may lead to permanent brain damage or death.
3. Neuritis - It refers to the damage of PNS sensory, motor or both nerve fibres. It may occur due to injury, deficiency of vitamin B or drugs. Some of its symptoms are tingling or numbness, pain, paralysis etc. It is treated with the help of pain killers such as aspirin, massage of weak muscles and stretching.
4. Scitica - It refers to the irritation of sciatic nerve.It is caused due to slipped invertebral disc when there occurs herniation of a disc in the lumbar area of the vertebral column. It may also be caused because of osteoarthritis and pregnancy if the position and weight of the foetus exerts pressure on the sciatic nerve.
5. Multiple sclerosis - It is a type of degenerative disease associated with the CNS. The normal myelin sheaths of nerve fibres are replaced with hardened scar tissue. This scar tissue interferes with the conduction of nerve impulse conduction. It is mainly found in people between 20-40 years of age. It causes are not known yet. Some of its symptoms are speech disturbances, visual impairment, uncoordinated handwriting. It also effects concentration.
6. Neuralgia - It refers to the pain that occurs in a particular area and is innervated by a sensory nerve of the PNS. It is difficult to find out the cause of the pain and its treatment.
Hope you liked this topic Diseases of Nervous System for notes of biology class 12.Please share it and comment if you want article on any other topic. You may also practice this topic using Worksheets for Science.
Related Topics
What is atherosclerosis? + Worksheets
Blood Clotting Process + Worksheets
What is blood pressure lower number? + Worksheets
ECG - How to read? + Worksheets
Blood Circulatory System in Humans + Worksheets
0 Comments