A muscular artery (or distributing artery) is a medium-sized

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 ...

that draws blood from an

elastic artery An elastic artery (conducting artery or conduit artery) is an artery with many collagen and elastin filaments in the tunica media, which gives it the ability to stretch in response to each pulse. This elasticity also gives rise to the Windkessel ...

and branches into "resistance vessels" including small arteries and

arterioles An arteriole is a small-diameter blood vessel in the microcirculation that extends and branches out from an artery and leads to capillaries. Arterioles have muscular walls (usually only one to two layers of smooth muscle cells) and are the pr ...

. Their walls contain larger number of smooth muscles, allowing them to contract and expand depending on peripheral blood demand. This contrasts to the mechanism of elastic arteries, which use their elastic properties to store the energy generated by the heart's contraction for a brief moment (elastic recoil). Examples of muscular arteries include 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 ...

femoral artery The femoral artery is a large artery in the thigh and the main arterial supply to the thigh and leg. The femoral artery gives off the deep femoral artery and descends along the anteromedial part of the thigh in the femoral triangle. It enters ...

and the splenic artery. Muscular arteries, along with elastic arteries, are common sites for

atherosclerosis Atherosclerosis is a pattern of the disease arteriosclerosis, characterized by development of abnormalities called lesions in walls of arteries. This is a chronic inflammatory disease involving many different cell types and is driven by eleva ...

Structure

The

tunica intima The tunica intima (Neo-Latin "inner coat"), or intima for short, is the innermost tunica (biology), tunica (layer) of an artery or vein. It is made up of one layer of endothelium, endothelial cells (and macrophages in areas of disturbed blood flo ...

of muscular arteries features a thin subendothelial layer and a prominent

internal elastic lamina The internal elastic lamina or internal elastic lamella is a layer of elastic tissue that forms the outermost part of the tunica intima of blood vessels. It separates tunica intima from tunica media. Histology It is readily visualized with light ...

, while the media may contain up to 40 layers of large

smooth muscle Smooth muscle is one of the three major types of vertebrate muscle tissue, the others being skeletal and cardiac muscle. It can also be found in invertebrates and is controlled by the autonomic nervous system. It is non- striated, so-called bec ...

cells interspersed with a variable number of elastic lamellae, depending on the vessel size. Only the larger muscular arteries possess an external elastic lamina. The

adventitia The adventitia ( ) is the outer layer of fibrous connective tissue surrounding an organ. The outer layer of connective tissue that surrounds an artery, or vein – the tunica externa, is also called the ''tunica adventitia''. To some degree, i ...

, the outermost layer, contains lymphatic capillaries,

vasa vasorum Vasa vasorum are networks of small blood vessels that supply the walls of large blood vessels, such as elastic arteries (e.g., the aorta) and large veins (e.g., the venae cavae). The name derives . Occasionally, two different singular forms ar ...

, and

nerves A nerve is an enclosed, cable-like bundle of nerve fibers (called axons). Nerves have historically been considered the basic units of the peripheral nervous system. A nerve provides a common pathway for the electrochemical nerve impulses called ...

, which may extend into the outer parts of the media. Under the microscope, muscular arteries can be identified by their clearly defined

. In constricted vessels, the elastic lamina of muscular arteries appears thick and kinky. The elastic lamina is best visualized using Verhoeff's stain, but can be easily detected in specimens stained using other techniques as a well-defined negative staining region.

References

‌ Arteries {{circulatory-stub