Slide 19: Application Questions

Application Questions

1. Myasthenia gravis is an autoimmune neuromuscular disease that leads to fluctuating muscle weakness and fatigue. In myasthenia gravis, antibodies act against the Acetylcholine (Ach) receptor, the receptor in the motor end plate for the Ach that stimulates contractions of the muscles. Some antibodies impair the abilities of the Ach, such as binding the receptors. Other antibodies cause destruction of the receptors by “complement fixation” or by inducing the muscle cell to eliminate the receptors. If the antibodies were to cause either one of these destructive behaviors, the subjects muscles would become weakened and fatigued.

2. Muscular dystrophy is a group of muscle diseases that weaken the musculoskeletal system and hamper locomotion. Muscular dystrophies are characterized by progressive skeletal muscle weakness, defects in muscle proteins, and the death of muscle cells as well as tissues. If someone has muscular dystrophy they will have delayed development of muscle motor skills, difficulty using different muscle groups, drooling, drooping eyelids, frequent falls, loss of strength and muscle mass, and problems walking.

3. Curare is a skeletal muscle relaxant drug belonging to the alkaloid family of organic compounds. This is a drug used for general anesthesia. Upon injection of curare, it acts as a neuromuscular blocking agent to produce flaccidity in striated muscle. The curare binds to the Ach receptors and keep them from activating therefore keeping the muscles from becoming stimulated, keeping them in the relaxed.

4. Botulinum toxin is a protein and neurotoxin. It prevents the release of neurotransmitter into the synapse. The synapse is the structure that permits the neuron to pass a chemical signal to another cell. If the botulinum toxin affects the release of neurotransmitter than the synapse will not be able to make a signal to help contractions of muscles. Therefore if a person was injected or poisoned by...