The subclavian artery becomes the axillary artery in the axillary region. This vessel supplies arterial blood to the entire arm area. Like all other arteries, the axillary artery can be affected by arteriosclerosis, which often results in infarction or necrosis as a late consequence.
What is the axillary artery?
The subclavian artery is also known as the subclavian artery and is responsible for supplying blood to the arms. Its branches also supply arterial vessels to the head and neck. The artery arises from the aortic arch on the left side and from the brachiocephalic trunk on the right side. Embedded in nerve cords of the brachial plexus, the vessel lies between the scalenus anterior and medius muscles within the posterior scalenus gap. In its course, the subclavian artery passes under the edge of the clavicle to enter the axilla. In this area, the blood vessel is called the axillary artery. Accordingly, the axillary artery is a continuation of the central subclavian artery, which gives off different vascular branches in its course to supply different torso tissues. Like all arteries, the axillary artery transports oxygen-rich blood from the cardiovascular system for distribution to the periphery of the body. In German literature, the process of the subclavian artery is also called the axillary artery.
Anatomy and structure
The axillary artery is referred to approximately from the outer edge of the first rib. Above this structure, the vessel is still called the subclavian artery. The end of the axillary artery lies at the caudal tendon border of the teres major muscle. At this point, the artery becomes the brachial artery. The morphological shape of the artery depends on the position of the upper arms. When the arm is bent at 90 degrees, the axillary artery is almost straight. When the arm is lying down, the blood vessel takes a cranially convex course, whereas when the arm is raised horizontally, it takes a cranially concave course. The artery has its proximal section in the depths of the axilla. The distal section is of skin and fascia. There is anatomically close connection between the vessel and the brachial plexus. Like all arteries, the axillary artery bears several layers. On top of the tunica intima near the lumen, composed of endothelial cells and connective tissue, lies the tunica media composed of smooth muscle. This is followed by the connective tissue layer tunica externa. The elastic fibers on both sides of the media are called membrana elastica interna.
Function and tasks
Like all arterial vessels, the axillary artery is responsible for transporting blood rich in oxygen, nutrients, and messengers from the center of the body. All tissues of the body depend on a permanent supply of arterial blood for survival. The blood within arteries is a transport medium for vital substances, without which the body tissues and organs can neither grow nor function. The axillary artery supplies different tissues of the body periphery by means of its branches. The branch superior thoracic artery is involved in the arterial supply of the upper thoracic region. With the thoracoacromial artery, the axillary artery also supplies the thoracic girdle region. The lateral thoracic artery branch supplies the lateral thoracic region, and the subscapular artery, as the largest branch of the axillary artery, supplies the tissue beneath the scapula. The branches arteria circumflexa humeri posterior and arteria circumflexa humeri anterior are involved in supplying the shoulder joint. Arteries such as the axillary artery contain sensory cells of deep sensation. These receptors provide permanent feedback to the nervous system about changes in blood pressure. The autonomic nervous system counter-regulates blood pressure as needed via contractions of the arterial musculature. Thus, the axillary artery indirectly contributes to the maintenance of circulation and interacts with cardiac activity. The supply of nutrients, oxygen, and neurotransmitters to the axilla, shoulder muscles, chest, and arms is nonetheless considered the main function of the vessel.
Diseases
The axillary artery is a relevant blood vessel in the context of surgical procedures, serving as an access for isolated limb perfusion of the arm. This treatment plays a role especially for patients with malignant melanoma and soft tissue sarcoma. The artery also gains clinical relevance due to pathological changes such as arterial disease.Arteriosclerosis is a common disease in the 21st century. Like all other arteries, the axillary artery can be affected by arteriosclerotic processes. In arteriosclerosis, so-called plaques are deposited in the blood vessels. This plaque consists of fats, connective tissue, calcium and thrombi. In this context, we speak of arteriosclerosis or hardening of the arteries. As a result of the hardening, the blood vessels become harder and stiffer in the course of arteriosclerosis. The loss of elasticity affects the entire circulatory system. Cracks and inflammation can form in the affected arteries, causing plaque formation to progress even further. Arteriosclerosis is often asymptomatic for years. The more the plaques constrict the vessel lumen, the more the arteries lose function. Infarctions are a common consequence, especially strokes in addition to heart attacks. Ruptures in the hardened vessel wall lead to the formation of blood clots, which can block entire vessels. The result is an insufficient supply of oxygen to the tissues supplied. Whole areas of tissue can die as a result. Aneurysms are also promoted by arteriosclerosis. Since the axillary artery supplies the entire arm region with arterial blood, arteriosclerotic processes in the artery have extreme consequences for a number of tissues. Even more frequently than arteriosclerosis in the axillary artery, physicians encounter compression-induced circulatory or sensory disturbances of the arm region in everyday clinical practice, which are usually based on entrapment of the brachial plexus.
