Axillary artery
Encyclopedia
In human anatomy
Human anatomy
Human anatomy is primarily the scientific study of the morphology of the human body. Anatomy is subdivided into gross anatomy and microscopic anatomy. Gross anatomy is the study of anatomical structures that can be seen by the naked eye...

, the axillary artery is a large blood vessel
Blood vessel
The blood vessels are the part of the circulatory system that transports blood throughout the body. There are three major types of blood vessels: the arteries, which carry the blood away from the heart; the capillaries, which enable the actual exchange of water and chemicals between the blood and...

 that conveys oxygenated blood
Blood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....

 to the lateral aspect of the thorax
Thorax
The thorax is a division of an animal's body that lies between the head and the abdomen.-In tetrapods:...

, the axilla (armpit) and the upper limb
Upper limb
The upper limb or upper extremity is the region in an animal extending from the deltoid region to the hand, including the arm, axilla and shoulder.-Definition:...

. Its origin is at the lateral margin of the first rib
Rib
In vertebrate anatomy, ribs are the long curved bones which form the rib cage. In most vertebrates, ribs surround the chest, enabling the lungs to expand and thus facilitate breathing by expanding the chest cavity. They serve to protect the lungs, heart, and other internal organs of the thorax...

, before which it is called the subclavian artery
Subclavian artery
In human anatomy, the subclavian arteries are two major arteries of the upper thorax , below the clavicle . They receive blood from the top of the aorta...

.

After passing the lower margin of teres major
Teres major muscle
The teres major muscle is a muscle of the upper limb and one of six scapulohumeral muscles. It is a thick but somewhat flattened muscle, innervated by the lower subscapular nerve .-Origin and insertion:...

 it becomes the brachial artery
Brachial artery
The brachial artery is the major blood vessel of the 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 at the elbow. It then divides into the radial and ulnar arteries...

.

Relation to pectoralis minor: division into three parts

The axillary artery is often referred to as having three parts, with these divisions based on its location relative to the pectoralis minor muscle, which is superficial to the artery.
  • First part - the part of the artery medial to pectoralis minor
  • Second part - the part of the artery that lies behind pectoralis minor
  • Third part - the part of the artery lateral to pectoralis minor

Relation to nerves and vein

The axillary artery is accompanied by the axillary vein
Axillary vein
In human anatomy, the axillary vein is a large blood vessel that conveys blood from the lateral aspect of the thorax, axilla and upper limb toward the heart...

 along its length.

In the axilla, it is surrounded by the brachial plexus
Brachial plexus
The brachial plexus is a network of nerve fibers, running from the spine, formed by the ventral rami of the lower four cervical and first thoracic nerve roots...

. The second part of the axillary artery is the reference for the locational descriptions of the cords in the brachial plexus
Brachial plexus
The brachial plexus is a network of nerve fibers, running from the spine, formed by the ventral rami of the lower four cervical and first thoracic nerve roots...

. For example, the posterior cord
Posterior cord
The posterior cord is a part of the brachial plexus. It consists of contributions from all of the roots of the brachial plexus.The posterior cord gives rise to the following nerves:...

 of the brachial plexus is so named because it lies posterior to the second part of the artery.

Branches

The axillary artery has several smaller branches. The branches can be remembered, in order, when traveling from the heart, with the mnemonic
Mnemonic
A mnemonic , or mnemonic device, is any learning technique that aids memory. To improve long term memory, mnemonic systems are used to make memorization easier. Commonly encountered mnemonics are often verbal, such as a very short poem or a special word used to help a person remember something,...

 "Screw The Lawyers Save A Patient", "Summertime: The Lakers Schedule Another Parade", or "She Tastes Like Sweet Apple Pie." The origin of these branches is highly variable (e.g. the posterior and anterior circumflex arteries often have a common trunk). An arterial branch is named for its course, not its origin.
  • First part (1 branch)
    • Superior thoracic artery
      Superior thoracic artery
      The superior thoracic artery is a small vessel normally arising from the first division of the axillary artery, but may arise from the thoracoacromial artery, itself a branch of the second division of the axillary artery....

       (Supreme thoracic artery)
  • Second part (2 branches)
    • Thoraco-acromial artery
    • Lateral thoracic artery
      Lateral thoracic artery
      In human anatomy, the lateral thoracic artery is a blood vessel that supplies oxygenated blood to the lateral structures of the thorax and breast....

      . If the lateral thoracic artery is not branching from the axillary artery, will most likely branch from the following (in order of likelihood): (1) thoracoacrominal, (2) third part of axillary artery, (3) suprascapular artery, (4) subscapular artery
  • Third part (3 branches)
    • Subscapular artery
      Subscapular artery
      The subscapular artery, the largest branch of the axillary artery, arises at the lower border of the Subscapularis muscle, which it follows to the inferior angle of the scapula, where it anastomoses with the lateral thoracic and intercostal arteries and with the descending branch of the transverse...

    • Anterior humeral circumflex artery
    • Posterior humeral circumflex artery
      Posterior humeral circumflex artery
      The posterior humeral circumflex artery arises from the axillary artery at the lower border of the subscapularis, and runs posteriorally with the axillary nerve through the quadrangular space.It winds around the neck of the humerus and is distributed to the Deltoid muscle and shoulder-joint,...



Continues as the brachial artery
Brachial artery
The brachial artery is the major blood vessel of the 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 at the elbow. It then divides into the radial and ulnar arteries...

 past the inferior border of the teres major.

Clinical Significance

The axillary artery may be safely clamped without endangering the arm, but only in a location proximal to the origin of the subscapular artery. The anastomotic network surrounding the scapula provides an alternate path for collateral circulation to the arm from arteries including the dorsal scapular artery
Dorsal scapular artery
The dorsal scapular artery is a blood vessel which supplies thelevator scapulae, rhomboids, and trapezius.-Origin:...

 and suprascapular artery
Suprascapular artery
The suprascapular artery is a branch of the thyrocervical trunk.-Course:At first, it passes downward and laterally across the scalenus anterior and phrenic nerve, being covered by the sternocleidomastoid muscle; it then crosses the subclavian artery and the brachial plexus, running behind and...

.

External links

- "Axillary Region: Parts of the Axillary Artery" - "The axillary artery and its major branches shown in relation to major landmarks."
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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