Vascular Anatomy and Physiology
Relevant anatomy
Know the upper extremity venous course: cephalic and basilic veins, cubital fossa connections, axillary, subclavian, and brachiocephalic veins to the superior vena cava. The basilic vein is often deeper and runs near the brachial artery and median nerve; the cephalic vein is more superficial and lateral. Central veins have predictable relationships to arteries and pleura, which explains complication patterns.
Physiology relevant to access
Venous return depends on valves, muscle pump, and respiratory variation. Understand how posture and tourniquet placement affect venous distension, and how arterial pressure and flow affect pulsatility. Recognize that low-flow states, hypovolemia, and prior thrombosis reduce vessel caliber and alter compressibility.
Traps
Questions test spatial relationships, not isolated names: which vessel lies adjacent to the brachial artery, or which side of the neck the internal jugular runs relative to the carotid. Another trap is assuming the largest visible vessel is the safest target without checking adjacency. Also beware of assuming symmetric anatomy; prior surgery, radiation, or dialysis access changes the map.
Rule of thumb
Anatomy questions usually test relationships: what lies next to the target, and what lies deep to it.
Worked example
A candidate selects a deep medial antecubital vein for access. The safer reasoning is that this region carries the brachial artery and median nerve; a more superficial, lateral vein with adequate caliber and no adjacent artery is preferred when clinically appropriate.