**Question:** All of the following effects are seen with cholinergic muscarinic receptor stimulation except:

A. Increased heart rate
B. Increased bronchoconstriction
C. Reduced saliva production
D. Increased bladder contractions

**Core Concept:** Cholinergic muscarinic receptors are a type of neurotransmitter receptor found in various parts of the body, including the heart, lungs, salivary glands, and urinary bladder. When activated, these receptors lead to specific physiological responses.

**Why the Correct Answer is Right:**

Option B (Increased bronchoconstriction) is incorrect because cholinergic muscarinic receptors are primarily responsible for bronchodilation (widening of bronchi), not bronchoconstriction (narrowing of bronchi). The correct answer is related to the opposite effect, bronchodilation.

**Why Each Wrong Option is Incorrect:**

Option A (Increased heart rate) is incorrect because cholinergic muscarinic receptors can increase heart rate, but the correct answer is related to a different effect, which is not seen with cholinergic muscarinic receptor stimulation.

Option C (Reduced saliva production) is incorrect because cholinergic muscarinic receptors are responsible for regulating saliva production, leading to increased saliva secretion.

Option D (Increased bladder contractions) is incorrect because cholinergic muscarinic receptors typically cause increased bladder contractions, which is not the correct answer.

**Clinical Pearl:** Cholinergic muscarinic receptors are linked to various physiological responses in the body, including stimulation of bronchodilation, increased saliva production, and increased bladder contractions. However, their actions are not directly opposite to the correct answer. For example, increased heart rate and reduced saliva production may be associated with cholinergic muscarinic receptor activation, but they are not the correct opposite effects. This understanding is crucial in understanding the roles of various receptors in physiological processes and their implications in medical diagnosis and treatment.