|Ulnar and radial arteries. Deep view.|
|Nerves of the left upper extremity.|
The boundaries of the cubital fossa include the following:
- superficial boundary (roof)- deep fascia reinforced by the bicipital aponeurosis (a sheet of tendon-like material that branches off the tendon of the biceps)
- deep boundary (floor)- brachialis and supinator muscles
- superior (proximal) boundary- imaginary line connecting medial epicondyle of the humerus to the lateral epicondyle of the humerus
- medial (ulnar) boundary- pronator teres muscle
- lateral (radial) boundary- brachioradialis muscle
The cubital fossa contains three main vertical structures (from lateral to medial):
- The radial nerve is in the vicinity of the cubital fossa, located between brachioradialis and brachialis muscles. It is often but not always considered part of the cubital fossa.
- The biceps brachii tendon
- The brachial artery. The brachial artery usually bifurcates near the apex (inferior part) of the cubital fossa into the radial artery (superficial) and ulnar artery (deeper)
- The median nerve
When the radial nerve is included, one can also use the mnemonic for lateral to medial: "Really Need Beer To Be At My Nicest". When the radial nerve is excluded, one can use the mnemonic TAN, for "Tendon Artery Nerve".
Several veins are also in the area (for example, the median cubital vein, cephalic vein, and basilic vein) but these are usually considered superficial to the cubital fossa, and not part of its contents.
During blood pressure measurements, the stethoscope is placed over the brachial artery in the cubital fossa. The cubital fossa is also an area used to palpate for the brachial pulse.
The area just superficial to the cubital fossa is often used for venous access (phlebotomy). A number of superficial veins can cross this region. Historically, back when (venous) blood-letting was practiced, the bicipital aponeurosis (the ceiling of the cubital fossa) was known as the "grace of God" tendon because it protected the contents of the fossa (i.e. the brachial artery and the median nerve).