What are the two main veins used for venipuncture?

The median cubital vein and cephalic vein are indeed the two main veins utilized for venipuncture in clinical settings. The median cubital vein, located in the antecubital fossa (the crease of the elbow), is the most commonly selected site. Its prominence and accessibility make it ideal for drawing blood, as well as for the insertion of IV catheters.

The cephalic vein, situated on the lateral aspect of the forearm and arm, is often used as an alternative when the median cubital vein is not suitable, such as in patients with difficult venous access or obesity. It is also palpable and provides a good route for blood draws. Both veins are well-positioned to minimize discomfort and provide adequate blood flow.

The other options include veins that are less commonly used for standard venipuncture. The femoral and jugular veins are typically reserved for specialized procedures in emergencies or certain medical conditions. The radial vein is smaller and less accessible for standard venipuncture, while the basilic vein can be more difficult to puncture due to its proximity to major nerves and arteries. The subclavian vein is generally used for central line placements and not for routine blood draws.