Source: Video and Images Created by Amanda Soderlind
In this lesson today, we will be discussing various disorders of the nervous system. So some disorders of the nervous system can be more serious than others, and the causes of disorders of the nervous system can vary quite a bit. So in this lesson, we're going to be taking a look at disorders that can be caused by physical injury, by genetics, by infections, or by breakdown of neurons.
So let's start with a category that we have up in this corner here. These are three different types of disorders of the nervous system that are caused by physical injury. OK, so these disorders can be caused by some sort of physical injury or trauma.
And if we take a look at seizures, we're going to start with seizures. So seizures are a brain disorder that can be caused by trauma from an injury or from birth, but there are also some other causes that can cause seizures as well. Some cases may be inherited.
A disease like epilepsy, for example, can cause seizures as well. So basically with seizures, the electrical activity in the brain becomes very chaotic, and nervous system signals aren't sent properly. So that can lead to seizures.
Concussions are another type of disorder that are caused by physical injury, and they're actually the most common brain injury. Oftentimes they're caused by some sort of sports injury. Paralysis is a type of injury where there's damage to the spinal cord.
And this kind of injury it can lead to limbs or other body parts not functioning correctly, because sometimes that nerve channel is disrupted. But some research is actually being done now using stem cells to try and repair damaged to spinal cord, which would be a huge breakthrough for people who are suffering from paralysis. If we take a look at these disorders over here, these are disorders caused by the breakdown of neurons.
OK so the breakdown of neurons can cause disorders such as Parkinson's disease or Alzheimer's disease. So Parkinson's disease happens when neurons, that are located in the thalamus of the brain, will die. And when this happens, the neurotransmitters, norepinephrine and dopamine, are not being produced, which effects normal muscle function.
And so this can be caused by various factors. It can be caused by head injury or sometimes being exposed to certain pesticides. So it's a disease that is debilitating, and is caused by neurons in the thalamus basically degenerating. Alzheimer's disease is one that you might be familiar with.
It's a disease that occurs from the degeneration of neurons and the buildup of amyloid proteins, which can lead to memory loss, or loss of intellectual functions. And it's oftentimes associated with aging. As a person gets older, the degeneration of neurons happens more quickly. And so usually this is linked to some sort of genetics factor as well. So these two disorders are caused by the breakdown of neurons.
If you take a look at our next group of disorders, here, all of these disorders are caused by some sort of infection. OK, so multiple sclerosis, encephalitis, and meningitis are all caused by some sort of infection. So we'll start by talking about multiple sclerosis.
This disease is a common disease of the nervous system among young adults. And it's an autoimmune disease that can be triggered by a viral infection. And basically what happens is that the myelin sheath, which covers a neuron, starts to deteriorate.
And when this happens, it causes nervous system signals not to be transmitted as efficiently as they would be normally. So these myelin sheath in the CNS are deteriorating, causing multiple sclerosis. Encephalitis is another disease caused by an infection where, basically, this infection causes the brain to swell or to become inflamed.
And viruses, like West Nile virus or herpes virus, are common viruses that can cause encephalitis. Meningitis is another disease caused by infection. Often this disease is fatal, and it's caused by a bacteria or viral infection. So what happens in this disease is that the meninges that cover the brain, you have three layers of mininges that cover your brain, those will swell up, because of this bacterial or viral infection. Which is often fatal if it's not caught very, very, very quickly.
Schizophrenia is another disease, or disorder, of the nervous system. And several factors actually go into schizophrenia, what can cause it. Things like changes to the brain can trigger this disorder.
And basically, with schizophrenia, a person becomes very paranoid, and might have auditory hallucinations, and they have social issues. So it's a mental disorder in which a person's social life is affected, because they have these paranoid and hallucination disorders. And autism is the last disorder we're going to talk about today.
Autism is a developmental disorder common in children. It shows up usually in childhood. In this type of disorder, there's a wide spectrum of how a person who has autism can be affected. Some don't show as much of an effect as others do, and some can be affected very, very severely by this disorder. But it affects thinking, language, and social skills. So this lesson has been an overview on disorders of the nervous system.
A type of brain injury where it is “shaken violently”; can cause disruption of neuron activity and should be monitored closely. There are different levels of concussions that can occur.
Complete loss of voluntary function.
Sudden, involuntary movement caused by erratic uncoordinated discharges by the brain.
A disease caused by degeneration of the midbrain (substantia nigra) that causes a marked inability of a person to relax their muscles.
A form of dementia caused by a slow degeneration of the cerebral cortex.
Inflammation of the meninges; caused by a bacterial or viral infection.
Swelling of the brain caused by infection.
A demyelinating disease that causes motor complications, loss of sensations, and have episodes often referred to as “flare-ups.”
A class of social disorders in which people have a hard time forming normal social relationships and display repetitive behavior.
A psychotic disorder that causes delusions, hallucinations, incoherent speech, inappropriate /negative behavior.