What Is the Anatomy of Arteries?

The aorta is the aorta. The thickest arterial tube in the body is the main conduit for blood to all parts of the body. The aorta and pulmonary arteries near the heart are called the aorta. Its tube wall is mainly composed of elastic fibers, so it is also called elastic artery.

The aorta is the aorta. The thickest arterial tube in the body is the main conduit for blood to all parts of the body. The aorta and pulmonary arteries near the heart are called the aorta. Its tube wall is mainly composed of elastic fibers, so it is also called elastic artery.

Chinese name

aorta

Foreign name

large artery

Including

Aorta, innominate artery

Explain

Has three layers of structure

Aortic structure:

1. Aorta:

Because the aorta contains a large number of elastic fibers, it can buffer the impact of the heart's blood flow when the heart contracts, and can maintain the balance of blood flow velocity when the heart is dilated. The aorta, especially the aorta, is a common site for atherosclerosis; inflammatory lesions can also occur in the aorta.

2. Artery:

All blood vessels and their branches from the ventricle are called arteries. It is a blood vessel that transports blood from the ventricle to organs and tissues throughout the body. The arteries and their branches from the left ventricle carry oxygen-saturated arterial blood, while the arteries and their branches from the right ventricle carry venous blood.

According to the size of the arterial diameter, it can be divided into four levels: large, medium, small and micro. There is no clear boundary between them. Its common basic structure is composed of three layers of inner, middle and outer membranes.

The aorta generally refers to the aorta, pulmonary artery, innominate artery, common carotid artery, subclavian artery, common iliac artery, and femoral artery. The median layer of this type of arterial wall is the thickest, mainly consisting of a large number of elastic fibers (about 40 to 70 layers for adults) and circular smooth muscles. Therefore, the elasticity of the tube wall is large, so it is also called elastic artery. It can buffer the strong pressure generated when the heart contracts, and can also use the elastic retraction to encourage the blood to continue to flow when the heart is dilated.

Except for the aorta, all arteries with a diameter of 1 mm or more belong to the middle artery. Its structure is characterized by the thickness of the medial layer of the tube wall, which is mainly composed of a large number of smooth muscles (about 10 to 40 layers for adults) and a small amount of elastic and collagen fibers. Therefore, the contraction of the tube wall is large, so it is also called muscular artery. It can regulate the blood supply of local organs.

Arterioles generally refer to arteries with a tube diameter of less than 1 mm and more than 300 microns. The structure of the tube wall is basically similar to the middle artery, but it gradually becomes thinner. The membrane layer is only composed of 1 to 4 smooth muscles, so it is also a muscular artery, and it also has the function of regulating blood flow in organs and tissues. Generally small arteries with a diameter of less than 300 microns are called arterioles. It finally migrates into capillaries.

Arteries can change with age. In addition to changes in normal development, these changes can also be degenerative and even pathological. Strengthening physical exercise can enhance the functional activity of the arteries to prevent or delay their degenerative or pathological changes.

Morphological structure of the aorta:

The aorta is a grade 1 to 3 artery from the heart. The diameter of the aorta is very large and has a round tube shape. The membrane contains a large amount of elastic tissue, also called elastic arteries. The human aorta, pulmonary artery, head and arm trunk, subclavian artery, and common carotid artery all belong to the aorta. The intima of the aorta is divided into 3 layers: the endothelium is composed of polygonal single-layer flat cells, the cytoplasm is not obvious, and the nucleus is mostly visible as a spindle; the lower endothelium is composed of fine glial fibers and an amorphous matrix, and elastic Fibers, fibroblasts, and migratory cells, etc .; the inner elastic membrane is composed of multiple layers of porous elastic membranes, also called window membranes. In the space between the membranes, there is a small amount of connective tissue and sometimes a small amount of smooth muscle. In recent years, aortic intimal cells have been considered to have the function of secreting certain microcirculation hormones to participate in the regulation of local microcirculation; the median membrane is the thickest of the three membranes, and its main component is the window membrane formed by elastic tissue. In the human aorta, there are about 50 to 60 layers surrounding the tube wall, and there are branches connected to each other. The interval between the membranes is wide, with a layer of circular smooth muscles and a small amount of connective tissue. The main component of the matrix in the middle membrane is sulfur-containing mucopolysaccharides, which are the components in the middle membrane that have the ability to shrink under normal circumstances. However, under pathological conditions, the matrix can form cartilage or calcify into bone. At this time, the arterial wall loses its elasticity and contraction ability, causing arteriosclerosis. The outer membrane is relatively thin, and the outer layer is a longitudinal row of glial fibers. There is an outer elastic membrane at the junction with the middle membrane, and there is no obvious boundary between the outer membrane and the middle membrane. There are also vascular nourishing ducts and nerves in the adventitia. The structure of the aorta is closely related to its function. Because it contains a large amount of elastic tissue, its wall expansion makes the diameter significantly larger, which can accommodate the blood that beats out when the heart contracts, and buffers the pressure of the heartbeat. When the heart relaxes, the elastic tissue of the aorta recovers and smooth muscles The contraction allows the blood in it to continue uninterruptedly to the distal end of the artery to maintain effective blood perfusion in the tissue. The adventitia of the aorta can prevent the elastic tissue in the medial membrane from being excessively stretched, thereby maintaining the blood pressure in the aorta to a certain degree. When the adventitia is damaged, the media can protrude outward due to the pressure in the tube, and aneurysms can be formed in severe cases.