human anatomy Human anatomy (gr. ἀνατομία, "dissection", from ἀνά, "up", and τέμνειν, "cut") is primarily the scientific study of the morphology of the human body. Anatomy is subdivided into gross anatomy and microscopic anatomy. Gross ...

, the radial artery is the main

artery An artery () is a blood vessel in humans and most other animals that takes oxygenated blood away from the heart in the systemic circulation to one or more parts of the body. Exceptions that carry deoxygenated blood are the pulmonary arteries in ...

of the lateral aspect of the

forearm The forearm is the region of the upper limb between the elbow and the wrist. The term forearm is used in anatomy to distinguish it from the arm, a word which is used to describe the entire appendage of the upper limb, but which in anatomy, techn ...

Structure

The radial artery arises from the bifurcation of 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 ...

in the

antecubital fossa 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 anteriorly to the elbow (antecubit ...

. It runs distally on the anterior part of the forearm. There, it serves as a landmark for the division between the

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 ...

and posterior compartments of the forearm, with the posterior compartment beginning just lateral to the artery. The artery winds laterally around the

wrist In human anatomy, the wrist is variously defined as (1) the carpus or carpal bones, the complex of eight bones forming the proximal skeletal segment of the hand; "The wrist contains eight bones, roughly aligned in two rows, known as the carpal ...

, passing through the

anatomical snuff box The anatomical snuff box or snuffbox or foveola radialis is a triangular deepening on the radial, dorsal aspect of the hand—at the level of the carpal bones, specifically, the scaphoid and trapezium bones forming the floor. The name originate ...

and between the heads of the first dorsal interosseous muscle. It passes anteriorly between the heads of the

adductor pollicis In human anatomy, the adductor pollicis muscle is a muscle in the hand that functions to Adduction, adduct the thumb. It has two heads: transverse and oblique. It is a fleshy, flat, triangular, and fan-shaped muscle deep in the Thenar eminence, ...

, and becomes the deep palmar arch, which joins with the deep branch of the

ulnar artery The ulnar artery is the main blood vessel, with oxygenated blood, of the Human Anatomical Terms#Anatomical directions, medial aspects of the forearm. It arises from the brachial artery and terminates in the superficial palmar arch, which joins ...

. Along its course, it is accompanied by a similarly named

vein Veins () are blood vessels in the circulatory system of 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 those of the pulmonary and feta ...

, the radial vein.

Branches

The named branches of the radial artery may be divided into three groups, corresponding with the three regions in which the vessel is situated.

In the forearm

* Radial recurrent artery - arises just after the radial artery comes off the brachial artery. It travels superiorly to anastomose with the radial collateral artery around the elbow joint * Palmar carpal branch of radial artery - a small vessel which arises near the lower border of the pronator quadratus * Superficial palmar branch of the radial artery - arises from the radial artery, just where this vessel is about to wind around the lateral side of the wrist.

At the wrist

* Dorsal carpal branch of radial artery - a small vessel which arises beneath the extensor tendons of the thumb * First dorsal metacarpal artery - arises just before the radial artery passes between the two heads of the first dorsal interosseous muscle and divides almost immediately into two branches which supply the adjacent sides of the thumb and index finger; the lateral side of the thumb receives a branch directly from the radial artery.

In the hand

* Princeps pollicis artery - arises from the radial artery just as it turns medially to the deep part of the hand. * Radialis indicis - arises close to the princeps pollicis. The two arteries may arise from a common trunk, the first palmar metacarpal artery. * Deep palmar arch - terminal part of radial artery.

Variations

In less than 1% of the population, the radial artery takes a superficial course in the anatomical snuff box. This arterial variation can be mistaken for the

cephalic vein In human anatomy, the cephalic vein (also called the antecubital vein) is a superficial vein in the arm. It is the longest vein of the upper limb. It starts at the anatomical snuffbox from the radial end of the dorsal venous network of hand, a ...

as accidental injection of this variant radial artery has been reported. Identifying arterial pulsation in the anatomical snuff box is therefore recommended.

Clinical significance

The radial artery lies superficially in front of the distal end of the

radius In classical geometry, a radius (: radii or radiuses) of a circle or sphere is any of the line segments from its Centre (geometry), center to its perimeter, and in more modern usage, it is also their length. The radius of a regular polygon is th ...

, between the tendons of the brachioradialis and flexor carpi radialis; it is here that clinician takes the radial pulse. (where it is commonly used to assess the

heart rate Heart rate is the frequency of the cardiac cycle, heartbeat measured by the number of contractions of the heart per minute (''beats per minute'', or bpm). The heart rate varies according to the body's Human body, physical needs, including the nee ...

and cardiac rhythm). Presence of ''radial pulse'' was thought to indicate a systolic

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 ...

of at least 70 mmHg, as estimated from the 50% percentile, although this was found to generally be an overestimation of a patient's true blood pressure. The radial artery can be less easily felt as it crosses the

. The radial artery is used for coronary artery bypass grafting and is growing in popularity among cardiac surgeons. Recently, it has been shown to have a superior peri-operative and post-operative course when compared to saphenous vein grafts. The radial artery is often punctured in a common procedure to obtain an

arterial blood gas An arterial blood gas (ABG) test, or arterial blood gas analysis (ABGA) measures the amounts of arterial gases, such as oxygen and carbon dioxide. An ABG test requires that a small volume of blood be drawn from the radial artery with a syringe an ...

. Such a procedure may first involve an Allen's test. The radial artery is also used to evaluate the

collateral circulation Collateral circulation is the alternate Circulatory system, circulation around a blocked blood vessel, artery or vein via another path, such as nearby minor vessels. It may occur via preexisting vascular redundancy (analogous to redundancy (engi ...

of blood through the hands; applying pressure through palpating the palmar arches results in paleness over the area being compressed; adequate collateral circulation can be ascertained by how quickly normal colour returns after the pressure is removed. The radial artery is a common site for the insertion of an arterial line, such as for blood pressure monitoring in an

intensive care unit An intensive care unit (ICU), also known as an intensive therapy unit or intensive treatment unit (ITU) or critical care unit (CCU), is a special department of a hospital or health care facility that provides intensive care medicine. An inten ...

. It is also commonly used for cerebral angiograms for the treatment of cerebral pathologies, such as strokes, cerebral aneurysms It is selected because it is accessible, and because of the low incidence of complications such as

thrombosis Thrombosis () is the formation of a Thrombus, blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. When a blood vessel (a vein or an artery) is injured, the body uses platelets (thrombocytes) and fib ...

Additional images

File:Gray417 color.PNG, Cross-section through the middle of the forearm. File:Gray527.png, The radial and ulnar arteries. File:Gray1235.png, Front of right upper extremity, showing surface markings for bones, arteries, and nerves. File:Slide9GGG.JPG, Radial artery and vein File:Gray416.png, Radial artery in the

anatomical snuffbox The anatomical snuff box or snuffbox or foveola radialis is a triangular deepening on the radial, dorsal aspect of the hand—at the level of the carpal bones, specifically, the scaphoid and trapezium bones forming the floor. The name originate ...

. File:Radial artery pseudaneurysm 20180607a.jpg, Pseudaneurysm involving the radial artery.

References

External links

Image at umich.edu – pulse
– medicalstudents.com * {{Authority control Arteries of the upper limb