The nurse administers a drug that causes vasoconstriction, contracted piloerection muscles, pupil dilation, closure of salivary sphincter, and male sexual emission. What receptor is the drug stimulating?

A) Bradycardia: Bradycardia is a common symptom of a cholinergic crisis. It results from excessive acetylcholine at the neuromuscular junction, which can overstimulate the parasympathetic nervous system, leading to a decrease in heart rate.

B) Rash: A rash is not a typical symptom of a cholinergic crisis. Rash might occur as a side effect of medications or other conditions, but it is not a hallmark feature of a cholinergic crisis in myasthenia gravis.

C) Vomiting: Vomiting is a potential symptom of a cholinergic crisis. It occurs due to the excessive stimulation of the parasympathetic nervous system, which can cause gastrointestinal distress and nausea.

D) Fever: Fever is not typically associated with a cholinergic crisis, but it can occur if there is an underlying infection or other condition. A cholinergic crisis itself usually leads to symptoms like weakness and excessive salivation, not fever.

E) Weakness: Weakness is a hallmark symptom of a cholinergic crisis, as it results from overstimulation at the neuromuscular junction, leading to muscle fatigue and paralysis. This is similar to the symptoms of myasthenia gravis, but in a cholinergic crisis, the weakness is more profound.

F) Drooling: Drooling is another common symptom of a cholinergic crisis. Excessive acetylcholine can lead to excessive salivation due to overstimulation of the parasympathetic nervous system.

A) Central nervous system (CNS), memory, and cognition: Myasthenia gravis (MG) primarily affects the neuromuscular junction, causing muscle weakness, not directly the central nervous system. While cognitive function may be affected in some patients due to fatigue or medication side effects, it is not the main system affected by MG.

B) Cardiovascular system and postural muscles: Myasthenia gravis primarily affects skeletal muscles, especially those responsible for voluntary movements like facial muscles, swallowing, and respiratory muscles. While MG can lead to general weakness, it does not typically affect the cardiovascular system directly.

C) Respiratory system and facial muscles: This is the correct answer. Myasthenia gravis primarily affects the voluntary muscles, particularly those controlling eye movements, facial expressions, swallowing, and breathing. The respiratory system is vulnerable due to weakness of the diaphragm and intercostal muscles, which can lead to respiratory distress in severe cases. Facial muscles are commonly affected, leading to symptoms like ptosis (drooping eyelids) and difficulty smiling or speaking.

D) Gastrointestinal system (GI) and lower extremity muscles: Although myasthenia gravis can cause generalized muscle weakness, it is not typically associated with the gastrointestinal system. The primary impact is on the voluntary muscles, such as those in the face, throat, and respiratory system. Lower extremity muscles can be affected, but the respiratory and facial muscles are more commonly involved.