The crease on the front of your elbow is a complex anatomical space with various structures passing through it. Understanding this area holds significance in medical procedures and overall arm function.
The Anatomical Name
The anatomical term for the crease of your elbow is the cubital fossa. The word “cubital” relates to the elbow, deriving from the Latin word cubitus. “Fossa” is a Latin term used in anatomy to describe a shallow depression or hollow. The cubital fossa describes this triangular depression found on the anterior, or front, surface of the elbow.
Anatomy and Contents of the Cubital Fossa
The cubital fossa is a triangular area on the anterior elbow, serving as a passageway for structures between the upper arm and forearm. Its boundaries are formed by specific muscles and an imaginary line. The superior border, forming the base of the triangle, is an imaginary line connecting the medial and lateral epicondyles of the humerus. The medial border is the lateral edge of the pronator teres muscle, while the lateral border is the medial edge of the brachioradialis muscle. The apex of this triangular space points downwards, where the brachioradialis and pronator teres muscles meet.
The floor of the cubital fossa is composed of the brachialis muscle proximally and the supinator muscle distally. The roof, from superficial to deep, includes the skin, superficial fascia, and the bicipital aponeurosis. Several structures are located here, arranged from lateral to medial. These include the radial nerve, the tendon of the biceps brachii muscle, the brachial artery, and the median nerve. The brachial artery branches into the radial and ulnar arteries within or near the cubital fossa, supplying blood to the forearm.
The median cubital vein, a superficial vein, is also located in the roof of the cubital fossa. This vein connects the cephalic and basilic veins, which are superficial veins of the arm. The radial nerve travels close to the brachioradialis muscle and divides into its deep and superficial branches within this area. The median nerve is found more medially, passing between the two heads of the pronator teres muscle.
Clinical Significance
The cubital fossa holds importance in medical practice due to the accessible location of its contents. It is a frequent site for venipuncture, the procedure for drawing blood or inserting intravenous (IV) lines. The median cubital vein, being large, stable, and often visible and palpable, is chosen for these procedures. Its position over the bicipital aponeurosis also provides protection to deeper structures like the brachial artery and median nerve during needle insertion.
The cubital fossa is also an anatomical landmark for measuring blood pressure. The brachial artery, which passes through this region, is where a stethoscope is placed to listen for blood flow sounds when inflating and deflating a blood pressure cuff. The pulse of the brachial artery can be felt just medial to the biceps tendon in this area. The presence of nerves like the median and radial nerves in this region means the cubital fossa is relevant in assessing nerve function and identifying potential nerve injuries. It also serves as a surgical landmark for procedures involving the elbow, allowing access to the underlying neurovascular structures.