How does polio kill motor neurons?
When it multiplies in the nervous system, the virus can destroy nerve cells (motor neurons) which activate skeletal muscles. These nerve cells cannot regenerate, and the affected muscles lose their function due to a lack of nervous enervation – a condition known as acute flaccid paralysis (AFP).
Does polio virus attack the nervous system?
Poliomyelitis, also called polio or infantile paralysis, is a highly infectious viral disease that may attack the central nervous system and is characterized by symptoms that range from a mild nonparalytic infection to total paralysis in a matter of hours.
Which nerves are destroyed in polio disease?
Making up about two percent of cases of paralytic polio, bulbar polio occurs when poliovirus invades and destroys nerves within the bulbar region of the brain stem. The bulbar region is a white matter pathway that connects the cerebral cortex to the brain stem.
What does polio do to the spinal cord?
Polio, or poliomyelitis, is a disabling and life-threatening disease caused by the poliovirus. The virus spreads from person to person and can infect a person’s spinal cord, causing paralysis (can’t move parts of the body).
Does the poliovirus have an envelope?
Poliovirus, the causative agent of paralytic poliomyelitis, is a small non-enveloped virus, with a single strand RNA genome encased in an icosahedral protein capsid.
Why did they stop using oral polio vaccine?
According to the World Health Organization, routine immunization with OPV must cease after the eradication of poliovirus because of the danger of outbreaks of circulating vaccine-derived poliovirus and the risk of VAPP.
Is polio a RNA or DNA virus?
Poliovirus, the prototypical picornavirus and causative agent of poliomyelitis, is a nonenveloped virus with a single-stranded RNA genome of positive polarity. The virion consists of an icosahedral protein shell, composed of four capsid proteins (VP1, VP2, VP3, and VP4), which encapsidates the RNA genome (1).
Is polio a neurological?
Polio, or poliomyelitis, is an infectious viral disease that can strike at any age and affects a person’s nervous system.
How does polio enter the bloodstream?
The virus enters through the mouth and multiplies in the throat and gastrointestinal tract, then moves into the bloodstream and is carried to the central nervous system where it replicates and destroys the motor neuron cells.
What animal did polio come from?
The discovery by Karl Landsteiner and Erwin Popper in 1908 that polio was caused by a virus, a discovery made by inoculating macaque monkeys with an extract of nervous tissue from polio victims that was shown to be free of other infectious agents.
Is polio upper or lower motor neuron?
Poliomyelitis is a disease of the lower motor neurons that affects the gray matter of the spinal cord, specifically the yen- tral horns. We report the MR imaging appearance of the cervi- cal spinal cord in a patient with this now uncommon disease.
What brain disease causes people to suffer from paralysis by killing the neurons in your spinal cord and motor cortex?
ALS affects nerve cells in the brain and spinal cord, leading to muscle weakness, a loss of motor function, paralysis, breathing problems, and, eventually, death.