**Question:** Glomus cells are found in which of the following locations?

**Core Concept:** Glomus cells, also known as Rydberg cells or metachromatic cells, are specialized smooth muscle cells present in the dermal plexus and subcutaneous tissue. They play a crucial role in regulating temperature by releasing noradrenaline or adrenaline in response to changes in temperature.

**Why the Correct Answer is Right:** Glomus cells are responsible for maintaining the body's temperature homeostasis by releasing noradrenaline or adrenaline in response to changes in temperature. When body temperature increases, these cells secrete noradrenaline, which constricts blood vessels, reducing heat loss to the environment. Conversely, when the body temperature decreases, they release adrenaline, causing blood vessels to dilate and enhance heat loss.

**Why Each Wrong Option is Incorrect:**

A. **Not mentioned:** The correct answer is not among the given options.
B. **Distant location:** Glomus cells are not found in the heart or skeletal muscle, making this option incorrect.
C. **Partially correct:** Glomus cells are present in the dermal plexus and subcutaneous tissue, but not in the lungs or liver, making this option partially correct.
D. **Negative:** Glomus cells are not found in the liver or spleen, making this option incorrect.

**Clinical Pearl / High-Yield Fact:** Glomus cells are essential for temperature regulation in the body. Understanding their distribution and function aids in interpreting skin changes in patients with disorders affecting these cells, such as essential tremor or Buerger's disease. Monitoring these cells' response can provide valuable information about the patient's overall health status.

**Correct Answer:** C. Glomus cells are found in the dermal plexus and subcutaneous tissue.