Knee joint pain in a deep sea diver is due to?
**Core Concept**
Nitrogen narcosis and decompression sickness are potential hazards for deep-sea divers, but knee joint pain is more likely related to a specific condition known as **nitrogen bubble formation** in the joint spaces. This phenomenon occurs when rapid changes in pressure cause nitrogen gas to form bubbles within the synovial fluid, leading to joint pain and inflammation.
**Why the Correct Answer is Right**
Nitrogen bubble formation in the joint spaces is a well-documented complication of deep-sea diving. The rapid decrease in pressure during ascent can cause dissolved nitrogen in the bloodstream to form bubbles, which can then migrate to the joints, causing pain and inflammation. This process is more likely to occur in the knee joint due to its weight-bearing nature and the increased pressure changes experienced during diving.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because nitrogen narcosis, a condition caused by the inhalation of high concentrations of nitrogen, primarily affects the central nervous system, leading to symptoms such as euphoria, confusion, and loss of judgment.
* **Option B:** This option is incorrect because gas embolism, a condition caused by the introduction of gas bubbles into the bloodstream, can lead to a range of systemic symptoms, including respiratory distress and cardiovascular instability, but is not the primary cause of knee joint pain in deep-sea divers.
* **Option C:** This option is incorrect because joint trauma or injury is a possible cause of knee joint pain, but is not directly related to the effects of deep-sea diving.
**Clinical Pearl / High-Yield Fact**
It's essential for divers to undergo gradual decompression and follow established protocols to minimize the risk of nitrogen bubble formation and associated joint pain.
**Correct Answer:** C.