A student ask the pharmacology instructor to describe the function of cholinergic agonist. What would be the instructor's reply?

A) Parkinson disease is characterized by an imbalance of dopamine and acetylcholine:
The decrease in dopamine results in an imbalance between dopamine and acetylcholine. Normally, dopamine and acetylcholine work in a balanced manner to regulate motor control. As dopamine levels decrease in Parkinson's disease, acetylcholine's effects become more prominent, leading to motor symptoms such as tremors, rigidity, and bradykinesia (slowness of movement).

B) Parkinson disease involves increased dopamine production and decreased acetylcholine:
This statement is incorrect. In Parkinson's disease, there is actually a decrease in dopamine production, not an increase. The disease is characterized by the degeneration of dopamine-producing neurons, leading to the motor symptoms typical of Parkinsonism. The imbalance in Parkinson's disease is primarily one of decreased dopamine and relatively increased acetylcholine activity.

C) Alzheimer disease is caused by decreased amounts of dopamine and degeneration of cholinergic neurons:
While Alzheimer's disease does involve a degeneration of cholinergic neurons (specifically those that release acetylcholine), the primary pathology is related to the accumulation of amyloid plaques and tau tangles, not primarily a decrease in dopamine. Alzheimer's disease is primarily associated with a deficiency in acetylcholine, not dopamine, leading to cognitive impairments, rather than motor deficits.

D) Alzheimer disease involves a possible excess of acetylcholine and neuritic plaques:
This statement is incorrect. Alzheimer's disease is characterized by a deficiency of acetylcholine, which plays a crucial role in memory and cognitive function. The hallmark pathologic features of Alzheimer's disease include the presence of neuritic plaques (formed from amyloid beta) and neurofibrillary tangles (composed of tau protein), not an excess of acetylcholine.

A) Decreased bowel sounds:
When the sympathetic nervous system (SNS) is activated, such as during stress or a "fight-or-flight" response, blood is redirected away from the gastrointestinal (GI) tract to vital organs like the heart and muscles. This results in decreased gastrointestinal motility and function, which is reflected in a reduction in bowel sounds. Decreased bowel sounds are a direct consequence of reduced blood flow and decreased activity in the GI system.

B) Increased blood glucose level:
While it is true that SNS activation can lead to an increase in blood glucose due to the release of catecholamines (e.g., epinephrine), this response is related to the body’s preparation for physical exertion and not directly a result of blood being diverted from the GI tract. The increase in glucose levels is more about energy mobilization rather than an effect on blood flow to the GI tract.

C) Decreased immune reaction:
Sympathetic stimulation can indeed have effects on immune function, typically suppressing immune responses during a stress response. However, this is not directly linked to blood being diverted away from the GI tract. Immune suppression is more about the body prioritizing immediate survival (e.g., diverting energy to muscles for fight-or-flight) rather than a specific physiological consequence of GI blood flow changes.

D) Increased blood pressure:
Sympathetic nervous system activation does lead to an increase in blood pressure due to vasoconstriction and increased heart rate. However, increased blood pressure is a broader systemic response to SNS stimulation, and it is not directly related to blood being diverted from the GI tract. Blood pressure increases as part of the general "fight-or-flight" response, but it does not specifically indicate changes in GI blood flow.