Internal opening of brachial fistula is located at
**Core Concept**
The brachial fistula is a type of arteriovenous fistula, which is an abnormal connection between an artery and a vein. This anomaly can occur due to trauma, surgery, or congenital conditions. Understanding the anatomy of the brachial artery and its relationship with nearby veins is crucial in identifying the internal opening of the brachial fistula.
**Why the Correct Answer is Right**
The brachial fistula typically involves the connection between the brachial artery and the median cubital vein. This occurs due to the close proximity of these two structures, allowing for a direct communication between the high-pressure arterial system and the low-pressure venous system. The median cubital vein is a superficial vein located on the anterior aspect of the forearm, making it a common site for fistula formation.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not specify a particular vein, making it too vague to be correct.
* **Option B:** This option is incorrect because it refers to a different type of fistula, one that involves the radial artery and the cephalic vein, which is not the location of the brachial fistula.
* **Option C:** This option is incorrect because it refers to a deep vein, which is not typically involved in the formation of a brachial fistula.
**Clinical Pearl / High-Yield Fact**
The brachial fistula is often associated with symptoms such as increased arm swelling, pain, and a palpable thrill or bruit over the affected area. It is essential to diagnose and treat this condition promptly to prevent complications such as venous hypertension and arterial thrombosis.
**Correct Answer: C. Basilic Vein**