**Question:** Clinical signs of atropine intoxication are as follows, EXCEPT:

A. Increased pupil size (mydriasis)
B. Rapid heart rate (tachycardia)
C. Delayed salivary secretion (hypomucorrhea)
D. Increased respiratory rate (tachypnea)

**Core Concept:**
Atropine is a drug that can cause various clinical signs due to its actions on the autonomic nervous system and its blockade of muscarinic acetylcholine receptors. These signs are a result of increased acetylcholine activity, which leads to various physiological effects. Muscarinic receptors are responsible for modulating pupil size, heart rate, saliva production, and respiratory rate.

**Why the Correct Answer is Right:**
Option C (hypomucorrhea) is incorrect because muscarinic receptors are primarily involved in saliva production via the parasympathetic nervous system. Atropine's blockade of these receptors would lead to decreased saliva production, not delayed secretion.

**Why Each Wrong Option is Incorrect:**
Option A (mydriasis) is a correct sign of atropine intoxication as the drug blocks the parasympathetic muscarinic receptors responsible for controlling pupil size.

Option B (tachycardia) is a correct sign of atropine intoxication since the drug blocks the parasympathetic muscarinic receptors involved in heart rate regulation.

Option D (tachypnea) is also a correct sign of atropine intoxication, as the drug blocks the parasympathetic muscarinic receptors involved in respiratory rate regulation.

**Clinical Pearl:**
Understanding the effects of atropine on the autonomic nervous system is crucial for recognizing its toxic effects. In clinical practice, atropine is sometimes used as a therapeutic agent, but its excessive use or overdose can lead to these clinical signs.

**Correct Answer:**
The correct answer is **Option C (hypomucorrhea)**.