What is the Pulmonary Vein?

The pulmonary veins connect the lungs with the large veins of the left atrium. Left and right two, the left and right superior and inferior pulmonary veins, respectively. Transports carbon dioxide from the lungs and transports oxygen-saturated blood to the left atrium, unlike a systemic vein.

The pulmonary veins connect the lungs with the large veins of the left atrium. Left and right two, the left and right superior and inferior pulmonary veins, respectively. Transports carbon dioxide from the lungs and transports oxygen-saturated blood to the left atrium, unlike a systemic vein.

TCM disease name

Pulmonary venous congestive pulmonary hypertension

English name

Pulmonary venous congestion in pulmonary arterial hypertension

Visiting department

Cardiopulmonary

Multiple groups

Middle-aged, elderly

Common locations

Cardiopulmonary

Common causes

Respiratory tract

Common symptoms

Blocked breathing

way for spreading

Respiratory infections

Pulmonary vein anatomy:

1. Pulmonary vein:

Pulmonary veins are the blood vessels that carry arterial blood from the lungs to the left atrium, so they are functional blood vessels of the lungs, which are different from systemic circulation veins. Pulmonary veins are nonvalvular. They belong to a capillary network surrounding the alveolar wall, converging step by step, and finally assembled into two left and right pulmonary veins. After exiting the hilum, they pass through the fibrous pericardium and inject them into the upper posterior portion of the left atrium. The right pulmonary vein is long and runs through the superior vena cava and the superior and posterior aspect of the right atrium. The left pulmonary vein is short and runs anterior to the thoracic aorta.

Pulmonary veins, two left and right, are large veins that carry arterial blood from the lungs back to the left atrium. Its genus branches from the alveolar capillary network and gradually converges into a pulmonary vein in each lung lobe. Because the pulmonary veins in the upper and middle lobe of the right lung form a branch at the root of the lung, there are still 4 pulmonary veins entering the left atrium, which are called the left and right superior pulmonary veins and inferior pulmonary veins, respectively. The main pulmonary vein and its branches are without valves. The right pulmonary vein is long and runs below the right pulmonary artery, behind the superior vena cava and right atrium. The left pulmonary vein is short and runs in front of the thoracic aorta. The left and right pulmonary veins pass through the fibrous layer of the pericardium and enter the left atrium.

The number of pulmonary veins entering the left atrium may vary. For example, it is not uncommon for two left pulmonary veins to merge into the left atrium; sometimes three right pulmonary veins (three leaves from the right lung) are opened in the left atrium. In addition, abnormal pulmonary veins may open in areas other than the left atrium. They can be divided into epicardial types according to their injection sites. They are merged into the left arm vein with a trunk or directly into the superior vena cava. 55%; paracardiac type, injected into the right atrium or coronary sinus, accounting for about 30%; subcardiac type, through a common trunk through the iliac crest, connected by a branch of the hepatic vein or portal vein to the inferior vena cava, about 12%; mixed type, accounting for about 3%.

2. Lungs:

The lungs are made up of bronchi, alveoli, blood vessels, nerves, lymph and connective tissue in the lungs. It is an important organ for gas exchange. It is located in the chest cavity, one on each side of the mediastinum, one on the left and one on the left. The lungs are flexible, such as sponges, which swell when inhaled and shrink when exhaled. The lungs are conical in shape, with the apex of the lungs above, the base of the lungs (also called the plantar surface), the costal surface on the outside, and the mediastinal surface on the inside. The center of the lung mediastinum is the hilum, which is the entrance to the bronchi, blood vessels, nerves, and lymphatic vessels. The surface of the lungs is covered with a smooth pleural layer of the pleura, which facilitates the breathing movement of the lungs. The right lung is divided into upper, middle and lower lobe, and the left lung is divided into upper and lower lobe. Respiratory bronchioles and alveoli are the gas exchange parts of the lungs.

Morphological structure of pulmonary vein and its surrounding structure:

The genus of the pulmonary veins originates from the capillary network around the alveoli and merges into small veins to form larger veins. Finally, each lung lobe gathers into a vein (3 in the right lung and 2 in the left lung), and enters the hilum After the roots of the lungs, 4 pulmonary veins (2 on the left and 2 on the right, and 1 on the right and middle lobe veins) were injected into the left atrium. The upper branches of the left and right pulmonary veins are located at the root of the lung, before and below the pulmonary artery; the lower branches of the pulmonary vein reside in the ligament at the lowest part of the lung root, and are close to the dorsal side. The right pulmonary vein is branched behind the superior vena cava, and the lower branch passes through the rear of the right atrium, and both are injected into the upper posterior portion of the left atrium. Both the superior and inferior branches of the left pulmonary vein traverse the front of the descending aorta and are injected into the upper posterior at the left margin of the left atrium. Pulmonary veins deliver arterial blood with more oxygen.

Pulmonary vein pulmonary vein malformation drainage:

Pulmonary venous malformation drainage is a malformed venous system in which blood from the pulmonary veins cannot enter the left atrium and flow into the systemic circulation due to embryonic developmental disorders. Divided into complete and incomplete pulmonary vein malformation drainage. Drainage of the complete pulmonary vein malformation was for all four pulmonary veins, which were not related to the left atrium, but all returned to the right atrium. Therefore, those who can survive after birth need right to left shunts. The right atrium receives blood from both the pulmonary vein and the vena cava at the same time. The blood volume increases and it is a mixture of unoxygenated and oxygenated blood. Part of it passes through the ventricular channel into the left atrium to supply the whole body. Clinical manifestations include cyanosis, dyspnea, right heart failure, stunting, and fatigue. Physical examination revealed signs similar to atrial septal defect, but with cyanosis, continuous vascular noise was also heard in the chest. The X-ray showed that the right atrium and right ventricle were enlarged, the pulmonary artery segment was bulging, and the pulmonary vascular shadow was increased. Electrocardiogram showed right atrium and right ventricle hypertrophy. Examination of the right heart catheter showed that the blood oxygen content of all cardiac chambers and large blood vessels was similar, but higher than those of the vena cava; the heart catheter could enter the malformed drainage pulmonary vein. Selective pulmonary angiography can show the drainage of pulmonary venous malformations. Incomplete or partial pulmonary vein malformation drainage refers to the ectopic drainage of a portion of the pulmonary veins into the right atrium. Commonly, the right pulmonary vein is introduced into the right atrium or superior vena cava or inferior vena cava or odd vein. About 20% of patients have other cardiovascular malformations, and the most common is atrial septal defect. Its clinical features and hemodynamic changes are similar to atrial septal defects. Complete ectopic drainage of the pulmonary vein can be performed with radical surgery. Partial pulmonary vein ectopic drainage, surgery is not necessary if there are no obvious symptoms; on the contrary, radical surgery should be performed. The natural prognosis of complete pulmonary vein ectopic drainage is poor, and some pulmonary vein ectopic drainage is similar to those of atrial septal defect.