What is the Pulmonary Artery?

Pulmonary arteries originate from the right ventricular pulmonary artery cone and below the aortic arch, and are divided into left and right pulmonary arteries at about the 5th thoracic vertebra. At the beginning of the pulmonary artery, there are three pulmonary valves that open along the flow and close against the flow. Inside the pulmonary arteries is venous blood containing carbon dioxide.

Chinese name: Pulmonary artery
Foreign name: Pulmonary Artery
Nature: organ

Department: Lungs
Function: Blood circulation
Flowing blood: Venous blood

Pulmonary artery anatomy:

1 Pulmonary artery 1. Pulmonary artery:

It is a thick, short trunk that transports venous blood to the lungs. Starting from the right ventricle's pulmonary artery, it rises obliquely from the front to the left of the aorta to the upper left and rear, reaching below the aortic arch, approximately equal to the lower edge of the fourth thoracic vertebra, and divided into left and right pulmonary arteries. A little to the left of the bifurcation, there is a connective tissue fibrous cord connected between the pulmonary artery and the lower edge of the aortic arch, called an arterial ligament, or an arterial duct cord, which is a trace left after the closure of an arterial duct during the embryonic period. So during the embryonic period, blood in the pulmonary artery is directed into the aorta. This arterial catheter is blocked shortly after birth. If it is not blocked, it is called an open duct, which is one of the congenital cardiovascular diseases.

The left pulmonary artery is short, crossing the thoracic aorta and the left bronchus to the left hilar to the left, and is divided into the upper and lower branches into the upper and lower lobe of the left lung; the right pulmonary artery is longer and rises to the right. After the aorta and superior vena cava, the front of the right bronchus and esophagus to the right hilum, it is divided into three branches that enter the upper, middle, and lower lobes of the right lung, and the left and right pulmonary arteries enter the lung through the hilum and follow the Branching and branching repeatedly, the finer and thinner, and finally formed a capillary network surrounding the alveolar wall, gas exchange is performed here. Therefore, the pulmonary artery is a functional blood vessel that transports venous blood to the lungs, and the vessels of the vegetative lung come from the branch of the thoracic aorta (bronchial artery).

2 Pulmonary artery 2. Pulmonary artery cone:

The extension of the right ventricle cavity to the pulmonary artery port is called the pulmonary artery cone.

3 Pulmonary artery 3. Right ventricle:

The right ventricle has a triangular pyramid shape with a bottom to right atrium opening and a pointed downward. In the ventricular cavity, there is a muscular bulge from the right atrioventricular vent to the pulmonary vent, called the supraventricular condyle. This case divides the right ventricle into the inflow and outflow tracts.

The inflow tract is the main part of the right ventricle, and there are many intersecting muscular bulges on the inner surface of the wall called the meat column. There are several thick and tapered meat columns called papillary muscles, which are generally three in front, back and medial. The entrance of the inflow tract is the right atrioventricular port, and there are three approximately triangular valves at the anterior, posterior, and medial edges of the port, called the tricuspid valve. The bottom of each valve is attached to the fibrous annulus (cardiac bone) around the right ventricular ostium, and its tip, or free edge, is connected to two adjacent papillary muscles by tendon cords. When the ventricle contracts, blood pushes the valve to close the atrioventricular opening. Due to the contraction of the papillary muscles and the tension of the chordae, the valve does not turn into the right atrium, prevents the blood from flowing backward into the atrium, and ensures the directional flow of blood. Any dysfunction such as valves, chordae, papillary muscles, and fibrous rings will have a serious impact on hemodynamics.

The outflow tract is the protruding part of the right ventricle to the upper left, which is called the arterial cone or funnel, and the inner surface of the wall is smooth and meatless. The outlet of the outflow tract is the pulmonary artery. There are three half-moon-shaped valves on the periphery of the mouth, called pulmonary valves. The free edge of the valve coincides with the direction of blood flow and faces the pulmonary artery. When the ventricle dilates, the valve that has been forced into the pulmonary artery presses the valve countercurrently, closing the free edges of the three valves to close the pulmonary artery opening to prevent blood from flowing back to the right ventricle.

Pulmonary Artery Morphological Structure:

The pulmonary trunk is a short, thick artery that starts from the arterial cone of the right ventricle and rises obliquely to the left and back, first in front of the ascending aortic root, then to the left, and below the aortic arch, around the 5th thoracic spine Height, divided into left and right pulmonary arteries. The left pulmonary artery is short, running to the left, through the front of the left main bronchus to the left hilum, and divided into two branches into the upper and lower lobe of the left lung. The right pulmonary artery is long and runs to the right. It reaches the right hilum through the ascending part of the aorta and the back of the superior vena cava. The branches of the left and right pulmonary arteries repeatedly branch in the lung parenchyma, accompanied by the branches of the bronchus, and finally reach the alveolar wall, forming a dense capillary network. Pulmonary arteries deliver venous blood that contains more carbon dioxide. There is a connective tissue cord between the left side of the pulmonary artery bifurcation and the lower edge of the aortic arch, called an arterial ligament. It is a relic after the embryonic arterial catheter was blocked. The arterial catheter was blocked shortly after birth. If it is kept for a long time without being blocked, it is called arterial duct patency, which is a congenital heart disease.

Pulmonary artery and pulmonary artery related diseases:

Pulmonary embolism:

Overview:

In addition to a few primary pulmonary arterial thrombosis, thrombosis or foreign bodies in many other organ diseases migrate to the pulmonary artery and cause secondary embolism, also known as pulmonary embolism. Pulmonary embolism can be caused by blood clots, cellulose, amniotic fluid, tumor tissue, parasites, fat, air gas, or foreign bodies. The main causes are: prolonged bed rest, vascular injury, and increased blood coagulation. Pulmonary embolism can be single or multiple and varies in size. When the main pulmonary artery and its branches are embolized, a series of obvious functional changes may occur, or even sudden death. Due to the large respiratory compensation mechanism and reserve function of the lung, a small single pulmonary artery embolism or multiple microembolisms will hardly cause significant functional changes. Some patients often have a history of peripheral vascular thrombosis, heart disease, surgery, childbirth, long-term bed rest, and arteriosclerosis. Clinical manifestations vary with the size of the embolism. Microembolism has almost no obvious symptoms. When the main pulmonary artery or its branches are embolized, the symptoms are obvious and sharp. The most common clinical symptoms are dry cough, chest pain, dyspnea and palpitations, and the onset is sudden. Pulmonary lobe and pulmonary artery embolism on it often show irritability, obvious cyanosis, jugular vein distension, and positive jugular vein reflux sign. Patients with embolism of the main pulmonary artery or its branches often die of sudden cardiac arrest shortly after onset. Pulmonary angiography is a more effective method for the diagnosis of pulmonary embolism, which can clearly show the location and extent of embolism, and provide a precise basis for surgical treatment. In addition to general treatment, anticoagulation, thrombolysis, surgery and other treatments can be selected according to the different conditions of the patient.