The cubital fossa, chelidon, or elbow pit, is the triangular area on the anterior side of the upper limb between the arm and forearm of a human or other hominid animals. It lies
anterior
Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...
ly to the
elbow
The elbow is the region between the 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 the media ...
(Latin ) when in
standard anatomical position
The standard anatomical position, or standard anatomical model, is the scientifically agreed upon reference position for Anatomical terms of location, anatomical location terms. Standard anatomical positions are used to standardise the position of ...
.
Boundaries
* superior (proximal) boundary – an imaginary horizontal line connecting the
medial epicondyle of the humerus
The medial epicondyle of the humerus is an epicondyle of the humerus bone of the upper arm in humans. It is larger and more prominent than the lateral epicondyle and is directed slightly more posteriorly in the anatomical position. In birds, whe ...
to the
lateral epicondyle of the humerus
The lateral epicondyle of the humerus is a large, tuberculated eminence, curved a little forward, and giving attachment to the radial collateral ligament of the elbow joint, and to a tendon common to the origin of the supinator and some of the ...
* medial (ulnar) boundary – lateral border of
pronator teres
The pronator teres is a muscle (located mainly in the forearm) that, along with the pronator quadratus, serves to pronate the forearm (turning it so that the palm faces posteriorly when from the anatomical position). It has two attachments, to t ...
muscle originating from the medial epicondyle of the humerus.
* lateral (radial) boundary – medial border of
brachioradialis
The brachioradialis is a muscle of the forearm that flexes the forearm at the elbow. It is also capable of both pronation and supination, depending on the position of the forearm. It is attached to the distal styloid process of the radius by way o ...
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
In human anatomy, the median cubital vein (or median basilic vein) is a superficial vein of the upper limb. It lies in the cubital fossa superficial to the bicipital aponeurosis. It connects the cephalic vein and the basilic vein. It becomes promi ...
, the
lateral cutaneous nerve of the forearm
The lateral antebrachial cutaneous nerve (or lateral cutaneous nerve of forearm) (branch of musculocutaneous nerve, also sometimes spelled "antebrachial") passes behind the cephalic vein, and divides, opposite the elbow-joint, into a volar and a ...
and the
medial cutaneous nerve of the forearm,
deep fascia
Deep fascia (or investing fascia) is a fascia, a layer of dense connective tissue that can surround individual muscles and groups of muscles to separate into fascial compartments.
This fibrous connective tissue interpenetrates and surrounds the m ...
reinforced by the
bicipital aponeurosis
The bicipital aponeurosis (also known as lacertus fibrosus) is a broad aponeurosis of the biceps brachii, which is located in the cubital fossa of the elbow. It separates superficial from deep structures in much of the fossa.
Structure
The bicip ...
(a sheet of tendon-like material that arises from the tendon of the biceps brachii)
* deep boundary (floor) –
brachialis
The brachialis (brachialis anticus), also known as the Teichmann muscle, is a muscle in the upper arm that flexes the elbow. It lies deeper than the biceps brachii, and makes up part of the floor of the region known as the cubital fossa (elbow pi ...
and
supinator
In human anatomy, the supinator is a broad muscle in the posterior compartment of the forearm, curved around the upper third of the radius. Its function is to supinate the forearm.
Structure
Supinator consists of two planes of fibers, between whi ...
muscles
Contents
The cubital fossa contains four main vertical structures (from lateral to medial):
*The
radial nerve
The radial nerve is a nerve in the human body that supplies the posterior portion of the upper limb. It innervates the medial and lateral heads of the triceps brachii muscle of the arm, as well as all 12 muscles in the posterior osteofascial comp ...
is in the vicinity of the cubital fossa, located between
brachioradialis
The brachioradialis is a muscle of the forearm that flexes the forearm at the elbow. It is also capable of both pronation and supination, depending on the position of the forearm. It is attached to the distal styloid process of the radius by way o ...
and
brachialis
The brachialis (brachialis anticus), also known as the Teichmann muscle, is a muscle in the upper arm that flexes the elbow. It lies deeper than the biceps brachii, and makes up part of the floor of the region known as the cubital fossa (elbow pi ...
muscles. It is often
but not always
considered part of the cubital fossa.
*The
biceps brachii
The biceps or biceps brachii ( la, musculus biceps brachii, "two-headed muscle of the arm") is a large muscle that lies on the front of the upper arm between the shoulder and the elbow. Both heads of the muscle arise on the scapula and join t ...
tendon
A tendon or sinew is a tough, high-tensile-strength band of dense fibrous connective tissue that connects muscle to bone. It is able to transmit the mechanical forces of muscle contraction to the skeletal system without sacrificing its ability ...
*The
brachial artery
The brachial artery is the major blood vessel of the (upper) arm. It is the continuation of the axillary artery beyond the lower margin of teres major muscle. It continues down the ventral surface of the arm until it reaches the cubital fossa ...
. The artery usually bifurcates near the apex (inferior part) of the cubital fossa into the
radial artery
In human anatomy, the radial artery is the main artery of the lateral aspect of the forearm.
Structure
The radial artery arises from the bifurcation of the brachial artery in the antecubital fossa. It runs distally on the anterior part of the f ...
(superficial) and
ulnar artery
The ulnar artery is the main blood vessel, with oxygenated blood, of the medial aspects of the forearm. It arises from the brachial artery and terminates in the superficial palmar arch, which joins with the superficial branch of the radial ar ...
(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 contr ...
The
ulnar nerve
In human anatomy, the ulnar nerve is a nerve that runs near the ulna bone. The ulnar collateral ligament of elbow joint is in relation with the ulnar nerve. The nerve is the largest in the human body unprotected by muscle or bone, so injury is ...
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
The medial epicondyle of the humerus is an epicondyle of the humerus bone of the upper arm in humans. It is larger and more prominent than the lateral epicondyle and is directed slightly more posteriorly in the anatomical position. In birds, whe ...
.
Several veins are also in the area (for example, the
median cubital vein
In human anatomy, the median cubital vein (or median basilic vein) is a superficial vein of the upper limb. It lies in the cubital fossa superficial to the bicipital aponeurosis. It connects the cephalic vein and the basilic vein. It becomes promi ...
,
cephalic vein
In human anatomy, the cephalic vein is a superficial vein in the arm. It originates from the radial end of the dorsal venous network of hand, and ascends along the radial (lateral) side of the arm before emptying into the axillary vein. At the ...
, and
basilic vein
The basilic vein is a large superficial vein of the upper limb that helps drain parts of the hand and forearm. It originates on the medial (ulnar) side of the dorsal venous network of the hand and travels up the base of the forearm, where its co ...
) 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 (the adjective is ''inguinal'', as in inguinal canal) is the junctional area (also known as the inguinal region) between the abdomen and the thigh on either side of the pubic bone. This is also known as the medial comp ...
,
popliteal fossa
The popliteal fossa (also referred to as hough, .html" ;"title="/sup>">/sup> or kneepit in analogy to the cubital fossa) is a shallow depression located at the back of the knee joint. The bones of the popliteal fossa are the femur and the tibia ...
,
armpit
The axilla (also, armpit, underarm or oxter) is the area on the human body directly under the shoulder joint. It includes the axillary space, an anatomical space within the shoulder girdle between the arm and the thoracic cage, bounded superiorl ...
and essentially the anterior part of the
neck
The neck is the part of the body on many vertebrates that connects the head with the torso. The neck supports the weight of the head and protects the nerves that carry sensory and motor information from the brain down to the rest of the body. In ...
), it is an area where blood vessels and nerves pass relatively superficially, and with an increased amount of
lymph node
A lymph node, or lymph gland, is a kidney-shaped organ of the lymphatic system and the adaptive immune system. A large number of lymph nodes are linked throughout the body by the lymphatic vessels. They are major sites of lymphocytes that inclu ...
s.
During
blood pressure
Blood pressure (BP) is the pressure of 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 "blood pressure" r ...
measurements
Measurement is the quantification of attributes of an object or event, which can be used to compare with other objects or events.
In other words, measurement is a process of determining how large or small a physical quantity is as compared t ...
, the
stethoscope
The stethoscope is a medical device for auscultation, or listening to internal sounds of an animal or human body. It typically has a small disc-shaped resonator that is placed against the skin, and one or two tubes connected to two earpieces. ...
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
Veins are blood vessels in humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated b ...
access (
phlebotomy
Phlebotomy is the process of making a puncture in a vein, usually in the arm, with a cannula for the purpose of drawing blood. The procedure itself is known as a venipuncture, which is also used for intravenous therapy. A person who performs a ph ...
) in procedures such as
injections and obtaining samples for
blood test
A blood test is a laboratory analysis performed on a blood sample that is usually extracted from a vein in the arm using a hypodermic needle, or via fingerprick. Multiple tests for specific blood components, such as a glucose test or a cholester ...
s. A number of superficial veins can cross this region. It may also be used for the insertion of a
peripherally inserted central catheter
A peripherally inserted central catheter (PICC or PIC line), less commonly called a percutaneous indwelling central catheter, is a form of intravenous access that can be used for a prolonged period of time (e.g., for long chemotherapy regimens ...
.
Historically, when (venous) blood-letting was practiced, the
bicipital aponeurosis
The bicipital aponeurosis (also known as lacertus fibrosus) is a broad aponeurosis of the biceps brachii, which is located in the cubital fossa of the elbow. It separates superficial from deep structures in much of the fossa.
Structure
The bicip ...
(the ceiling of the cubital fossa) was known as the "grace of God" tendon because it protected the more important contents of the fossa (i.e. the brachial artery and the median nerve).
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
The cubital tunnel is a space of the dorsal medial elbow which allows passage of the ulnar nerve around the elbow. It is bordered medially by the medial epicondyle of the humerus, laterally by the olecranon process of the ulna and the tendinous arc ...
*
Median cubital vein
In human anatomy, the median cubital vein (or median basilic vein) is a superficial vein of the upper limb. It lies in the cubital fossa superficial to the bicipital aponeurosis. It connects the cephalic vein and the basilic vein. It becomes promi ...
*
Peripherally inserted central catheter
A peripherally inserted central catheter (PICC or PIC line), less commonly called a percutaneous indwelling central catheter, is a form of intravenous access that can be used for a prolonged period of time (e.g., for long chemotherapy regimens ...
References
External links
Diagrams at frca.co.ukAnimated Venous access tutorials
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Upper limb anatomy