The antecubital fossa is a small cavity in the elbow joint. This triangular opening is important to lab technicians because three main veins run through it. All are viable sources for blood samples and are easily accessible through the skin of the inner elbow, which is why many blood draws are performed at this site. The median nerve, which senses stimuli all along the arm, and the brachial artery, which carries blood into the arm and hand, also pass through this area. So does a tendon of the biceps, which helps the biceps muscles expand and contract.
Medical professionals depend on this small, but important, part of the body not only as a primary site for drawing blood, but also as one of the most accessible and dependable sites at which to measure blood pressure. A healthcare professional can use a stethoscope placed over the inner elbow to hear the blood flow through the brachial artery. Used in conjunction with a blood pressure cuff placed on the upper arm, this offers an accurate reading. This site may also be used for taking a patient's pulse and for inserting an IV.
Physicians and orthopedists treating patients who have injuries to bones, ligaments, or tendons in the arm or elbow will check for damage to the anatomy of the antecubital fossa. An injury that affects this cavity can cause pain, sensitivity, and tingling in the forearm and hand because of the presence of the median nerve. Elbow injuries can also cause swelling in the hand due to damage to any of the three veins or lack of blood flow due to damage to the brachial artery. Common injuries and conditions affecting this space include fractures to the ulna, radius or humerus and dislocation of the elbow. Regular participation in certain sports may lead to elbow troubles, hence conditions such as "tennis elbow" and "golfer's elbow."
Unfortunately, the easy access to nerves and arteries that makes taking blood and measuring blood pressure so handy also offers an easy site for illicit drug use. Injecting a drug directly into a major blood vessel may cause it to take effect more quickly, producing a faster "high." This extremely dangerous practice can lead to deterioration of the blood vessels as well as sudden death. Habitual users are often identifiable by the presence of "track" or needle marks on the inner elbow.