Discussion Topic #1: Myasthenia Gravis

In preparation for the essay section in exam 2, we will focus on the topic of neuromuscular disorders – specifically, Myasthenia Gravis. MG is discussed in Ch. 9 and is a great clinical case study to integrate your understanding of the nervous system and skeletal muscle.

Answer the following questions for this discussion board assignment:

1. What is the problem for patients with MG?

2. How does MG impact the normal mechanisms involved in the neuromuscular junction and, eventually, skeletal muscle contraction? **Discuss the the NORMAL mechanism at the NMJ for both neurotransmitter release at the presynaptic motor neuron AND the mechanism for skeletal muscle fiber contraction**

3. Based on your understanding of the normal physiology mechanism of skeletal muscle contraction and the pathophysiology of MG, how do treatments using acetylcholinesterase inhibitors help MG patients?

Discussion Topic #1: Myasthenia Gravis

1. The problem in patients with myasthenia gravis is that the antibodies block the acetylcholine receptors at the neuromuscular junction. Because of this, the acetylcholine could not bind to the receptors, and therefore, blocks the neuromuscular transmission or could not respond to nerve impulses. Therefore, this prevents muscle contraction, and patients suffering from myasthenia gravis experience the weaknes in the voluntary skeletal muscles.