Myasthenia gravis is an example of

Options

A. Viral disease
B. Immunological disease
C. Autoimmune disease
D. Allergic reactions.

Answer

**Step-by-Step Solution:**

1. **Understanding Myasthenia Gravis**: Myasthenia gravis is a condition that affects the communication between nerves and muscles. It is characterized by weakness and rapid fatigue of voluntary muscles.

2. **Mechanism of Myasthenia Gravis**: In myasthenia gravis, there is a defect in the transmission of signals at the neuromuscular junction. This junction is where the nerve cells communicate with the muscles.

3. **Role of Acetylcholine**: The neurotransmitter involved in this communication is acetylcholine. Normally, acetylcholine is released from the nerve terminal and binds to receptors on the muscle, leading to muscle contraction.

4. **Autoimmune Response**: In myasthenia gravis, the body’s immune system mistakenly produces antibodies that attack and destroy the acetylcholine receptors on the muscle cells. This prevents acetylcholine from binding effectively, leading to impaired muscle contraction.

5. **Classification of Myasthenia Gravis**: Due to the involvement of the immune system and the production of antibodies against the receptors, myasthenia gravis is classified as an autoimmune disease.

6. **Symptoms**: The lack of effective transmission of signals results in symptoms such as muscle weakness, fatigue, and in severe cases, paralysis of skeletal muscles.

7. **Conclusion**: Therefore, myasthenia gravis is an example of an autoimmune disease.