Question

Normally, rapid repeated stimulus applied to the skin above a nerve by a stimulating electrode results in temporal summation and increased muscle contraction. In Wendy’s nerve conduction test, the opposite occurred. What is the mechanism that caused Wendy’s nerve conduction test to be abnormal?

Wendy has myasthenia gravis.

Answer 1

As Windy has myasthenia gravis this become the reason for his abnormal reaction on the muscles.

Myasthenia gravis is a autoimmune disorder and thus the muscle gets weakened due to the weakness of contraction. As the immune cells attack the neuromuscular junction and acts on the receptor for the acetylcholine to bind the neurons cannot actively pass the impulse to the muscle and thus promotes it's contraction. Unlike other people as Windy has problem with this his first stimuli produced a feeble contraction and when second stimuli is produced the acetylcholine now formed fail to act on the receptors as the available receptors are damaged. So the temporal summation doesn't occur instaed of that the contraction is slowed down.