Which of the following conditions shows assymetric type of descending paralysis? 1. Botulism 2. Desseminated Diphtheria 3. Tetanus 4. Poliomyelitis
1 Answer
Explanation:
All the given diseases are characterized by descending type of paralysis.
But it is symmetrical for the first three,whereas it is assymetrical for the last one,hence a patient suffering from polio finds inability to move one arm,whether he/she can move the other arm nicely,it is because the virus itself invades the ventral root of spinal cord after reaching by means of propagation through sensory nerves and destroys the motor nerves.
Botulinum toxin produced by Clostridium botulinum,prevents snaring between v snare and t snare proteins,which inhibits the release of Acetyl choline from the synaptic vesicle at the motor end plate,so muscle contraction is not initiated.
Diptheria toxin has A-B pattern,where B is the main enzyme and A is the active moiety,it blocks EF-2.
Clostridium tetani produces one toxin known as tetanospasmin,which has low molecular weight as well as high molecular weight fraction, the later helps the entry of the previous in the nerves which post synaptically blocks GABA release,resulting in inhibition of action of Renshaw cells,which results in limitless muscle movements.
