The cubital fossa, antecubital fossa, chelidon, inside of elbow, or, humorously, wagina,
is the area on the anterior side of the upper part between the arm and forearm of a human or other hominid animals. It lies
anterior
Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ...
ly to the
elbow
The elbow is the region between the upper arm and the forearm that surrounds the elbow joint. The elbow includes prominent landmarks such as the olecranon, the cubital fossa (also called the chelidon, or the elbow pit), and the lateral and t ...
(antecubital) (Latin ) when in
standard anatomical position. The cubital fossa is a triangular area having three borders.
Boundaries
* superior (proximal) boundary – an imaginary horizontal line connecting the
medial epicondyle of the humerus to the
lateral epicondyle of the humerus
* medial (ulnar) boundary – lateral border of
pronator teres muscle originating from the medial epicondyle of the humerus.
* lateral (radial) boundary – medial border of
brachioradialis muscle
originating from the lateral supraepicondylar ridge of the humerus.
* apex – it is directed inferiorly, and is formed by the meeting point of the lateral and medial boundaries
* superficial boundary (roof) – skin, superficial fascia containing the
median cubital vein, the
lateral cutaneous nerve of the forearm and the
medial cutaneous nerve of the forearm,
deep fascia reinforced by the
bicipital aponeurosis (a sheet of tendon-like material that arises from the tendon of the biceps brachii)
* deep boundary (floor) –
brachialis and
supinator muscles
Contents
The cubital fossa contains four main vertical structures (from lateral to medial):
*The
radial nerve passes underneath the
brachioradialis muscle where it divides into deep and superficial branches. It is not always considered part of the cubital fossa but is in the vicinity.
*The
biceps brachii tendon
A tendon or sinew is a tough band of fibrous connective tissue, dense fibrous connective tissue that connects skeletal muscle, muscle to bone. It sends the mechanical forces of muscle contraction to the skeletal system, while withstanding tensi ...
*The
brachial artery. The artery usually bifurcates near the apex (inferior part) of the cubital fossa into the
radial artery (superficial) and
ulnar artery (deeper)
*The
median nerve
The median nerve is a nerve in humans and other animals in the upper limb. It is one of the five main nerves originating from the brachial plexus.
The median nerve originates from the lateral and medial cords of the brachial plexus, and has cont ...
The
ulnar nerve is also in the area, but is not in the cubital fossa; it occupies a groove on the posterior aspect of the
medial epicondyle of the humerus.
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.
From lateral to medial, the order of the contents within the cubital fossa can be described by the acronym TAN: tendon, artery, nerve
Clinical aspects

Like other flexion surfaces of large joints (
groin
In human anatomy, the groin, also known as the inguinal region or iliac region, is the junctional area between the torso and the thigh. The groin is at the front of the body on either side of the pubic tubercle, where the lower part of the abdom ...
,
popliteal fossa,
armpit and essentially the anterior part of the
neck), it is an area where blood vessels and nerves pass relatively superficially, and with an increased amount of
lymph nodes.
During
blood pressure
Blood pressure (BP) is the pressure of Circulatory system, circulating blood against the walls of blood vessels. Most of this pressure results from the heart pumping blood through the circulatory system. When used without qualification, the term ...
measurements, the
stethoscope is placed over the brachial artery in the cubital fossa. The artery runs medial to the biceps tendon. The brachial pulse may be palpated in the cubital fossa just medial to the tendon.
The area just superficial to the cubital fossa is often used for
venous access (
phlebotomy) in procedures such as
injections and obtaining samples for
blood tests. A number of superficial veins can cross this region. It may also be used for the insertion of a
peripherally inserted central catheter.
Historically, during
bloodletting, the
bicipital aponeurosis (the ceiling of the cubital fossa) was known as the "grace of God tendon" because it separated and protected the more important contents of the fossa such as the
brachial artery and the
median nerve
The median nerve is a nerve in humans and other animals in the upper limb. It is one of the five main nerves originating from the brachial plexus.
The median nerve originates from the lateral and medial cords of the brachial plexus, and has cont ...
.
Statistically, the antecubital fossa is the least tender region for peripheral intravenous access, although it provides a greater risk for venous thrombosis.
Additional images
See also
*
Cubital tunnel
*
Median cubital vein
*
Peripherally inserted central catheter
References
External links
Diagrams at frca.co.ukAnimated Venous access tutorials
{{Authority control
Upper limb anatomy