In Raynaud’s disease true is :
**Core Concept**
Raynaud's disease is a disorder that affects blood flow to the fingers and toes, and sometimes the ears, nose, and lips. It is characterized by a sudden and temporary narrowing of the blood vessels in response to cold temperatures or stress, leading to a lack of blood flow and oxygen to the affected areas.
**Why the Correct Answer is Right**
The correct answer is related to the pathophysiology of Raynaud's disease, which involves the vasoconstriction of small arteries and arterioles in response to cold temperatures or stress. This vasoconstriction is mediated by the release of certain neurotransmitters, such as norepinephrine, which causes the blood vessels to constrict. The affected areas then become pale, cold, and painful due to the lack of blood flow.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe the pathophysiology of Raynaud's disease. Vasodilation is the opposite of vasoconstriction, and is not a characteristic of this disorder.
**Option B:** This option is incorrect because it is not a specific or accurate description of the pathophysiology of Raynaud's disease. The disorder is not primarily caused by an abnormality in the blood vessels themselves, but rather by a dysfunction in the nervous system that controls blood flow.
**Option C:** This option is incorrect because it is not a characteristic of Raynaud's disease. The disorder is not primarily caused by a lack of oxygen to the affected areas, but rather by a temporary narrowing of the blood vessels.
**Clinical Pearl / High-Yield Fact**
Raynaud's disease is often triggered by exposure to cold temperatures, stress, or certain medications, and can be exacerbated by smoking or other vascular risk factors. It is essential to identify and manage these triggers to prevent episodes of vasospasm and minimize the risk of tissue damage.
**Correct Answer:** C.