Last Updated on November 27, 2025 by Bilal Hasdemir

At Liv Hospital, we focus on trusted, patient-centered care in the lungs. The pulmonary artery system is key. It carries blood from the heart to the lungs for oxygen.
The main pulmonary artery, or trunk, is about 5 cm long and 2-3 cm wide. It starts in the right ventricle and splits into two arteries. These supply the lungs.
Knowing about the pulmonary artery system is key. It helps us diagnose and treat heart and lung issues.
The pulmonary circulation system carries deoxygenated blood from the heart to the lungs. We will dive into its details, including its main parts and roles.
Deoxygenated blood starts in the right ventricle of the heart. It goes through the pulmonary valve into the pulmonary trunk. Then, it splits into the right and left pulmonary arteries, heading to the lungs.
In the lungs, the blood goes through smaller arteries and arterioles. It reaches the pulmonary capillaries, where gas exchange happens. Oxygen moves into the blood, and carbon dioxide moves out.
Pulmonary circulation is different from systemic circulation. Systemic circulation sends oxygen-rich blood to the body’s tissues. Pulmonary circulation, on the other hand, sends deoxygenated blood to the lungs.
| Characteristics | Pulmonary Circulation | Systemic Circulation |
|---|---|---|
| Blood Oxygenation | Deoxygenated | Oxygenated |
| Pressure | Lower pressure | Higher pressure |
| Function | Gas exchange in lungs | Oxygen delivery to tissues |
The emergence of pulmonary circulation was key in life’s evolution. It made blood oxygenation more efficient. This allowed life forms to grow bigger and more complex.
This shows how advanced and detailed the human heart system is.
The pulmonary trunk is a key blood vessel that starts in the right ventricle of the heart. It plays a big role in getting blood to the lungs. We will look at its size, where it is, and how it develops.
The pulmonary trunk is about 5 cm long and 2-3 cm wide. Its size is a key sign of heart health. Studies have found a strong link between its width and blood pressure in the lungs in kids.
| Dimension | Measurement |
|---|---|
| Length | Approximately 5 cm |
| Diameter | 2-3 cm |
The pulmonary trunk is found in the pericardial cavity, coming from the right ventricle. It’s near other important heart parts and the aorta. Knowing where it is helps doctors diagnose and treat heart issues.
The pulmonary trunk forms as the heart develops and the truncus arteriosus splits. Problems during this time can cause heart defects. This shows how vital proper development is.
In summary, the pulmonary trunk is a vital part of the lung’s blood flow. Its size, location, and how it grows are all key to understanding its role and importance in health.
It’s important to know about the right and left pulmonary arteries to understand how blood circulates in the lungs. These arteries branch off from the pulmonary trunk. They carry deoxygenated blood to the lungs.
The right and left pulmonary arteries are different in size and shape. The right pulmonary artery is longer and bigger. It goes horizontally to the right, behind the aorta and superior vena cava. On the other hand, the left pulmonary artery is shorter and smaller. It goes in front of the descending aorta.
These differences help us understand how each artery reaches its lung.
The right pulmonary artery sends blood to the right lung. The left pulmonary artery goes to the left lung. This is key for the lungs to oxygenate the blood.
Each artery splits into branches for the lung lobes. The right artery goes to the right lung’s three lobes. The left artery goes to the left lung’s two lobes.
The right pulmonary artery carries deoxygenated blood to the right lung. It’s essential for the right lung’s oxygenation. Its structure helps it distribute blood well to the right lung’s lobes.
It’s important to know how the pulmonary arteries work. They carry deoxygenated blood to the lungs. There, the blood gets oxygen.
The pulmonary artery system has a special branching pattern. It starts with the main pulmonary artery. Then, it splits into the right and left pulmonary arteries.
The arteries get smaller and smaller, becoming lobar and segmental arteries. These supply different parts of the lungs. Eventually, they reach a network of tiny blood vessels where oxygen and carbon dioxide are exchanged.
The pulmonary arteries and the bronchial tree grow in a similar way. This helps blood reach the right spots in the lungs for gas exchange. It makes oxygenating the blood more efficient.
The pulmonary arteries are made for the lungs’ needs. They have thin walls and big spaces. This lets blood flow easily to the lungs.
| Artery Level | Branching Pattern | Function |
|---|---|---|
| Main Pulmonary Artery | Divides into right and left pulmonary arteries | Delivers deoxygenated blood to lungs |
| Lobar Arteries | Branch into segmental arteries | Supplies blood to lung lobes |
| Segmental Arteries | Further subdivide into subsegmental arteries | Supplies blood to lung segments |
Learning about the pulmonary arteries helps us see their importance. They are key to keeping our lungs working well and our body healthy.
It’s key to know about lobar and segmental pulmonary arteries for diagnosing and treating lung issues. These arteries branch out to supply blood to the lungs’ different parts.
The lobar arteries feed the lung lobes. The right lung has three lobes, and the left has two. These arteries branch from the main pulmonary artery to reach these lobes. They match up with the bronchial tree, making sure each part of the lung gets enough blood.
| Lung | Number of Lobes | Lobar Arteries |
|---|---|---|
| Right Lung | 3 | 3 lobar arteries (upper, middle, lower) |
| Left Lung | 2 | 2 lobar arteries (upper, lower) |
Segmental arteries branch from lobar arteries to specific lung parts. Knowing this is key for treating conditions like pulmonary embolism or lung tumors. It helps doctors plan surgeries or targeted treatments.
There can be variations in how pulmonary arteries branch. These changes can affect blood flow to lung segments. Knowing about these variations is important for accurate diagnosis and treatment.
In summary, lobar and segmental pulmonary arteries are essential for lung function. Their distribution and branching patterns have big implications for treatment.
Pulmonary arterioles are key for efficient gas exchange. They control blood flow to the lungs. As the smallest parts of the pulmonary arteries, they are vital.
The structure of pulmonary arterioles is special. They have thin walls that can change size. This lets them control blood pressure and flow in the lungs.
Hypoxic vasoconstriction is a key function. It makes these arterioles narrow when oxygen levels are low. This ensures blood goes to areas with more oxygen.
The pulmonary arteriole function is linked to lung health. When they work right, they keep blood flow and pressure in the lungs optimal.
Pulmonary arterioles also affect pulmonary hypertension. This is high blood pressure in lung arteries. Problems with these arterioles can lead to this condition. It shows how important they are for lung circulation.
In summary, the pulmonary arteriole function is essential for lung blood flow and gas exchange. Knowing how they work and their role in diseases helps us understand lung circulation better.
The pulmonary capillary network is key to breathing. It helps move oxygen from the lungs to the blood and carbon dioxide from the blood to the lungs. This network of tiny blood vessels is around the alveoli, the air sacs in the lungs.
Pulmonary capillaries are made for efficient gas exchange. They have a large surface area and thin walls. This lets gases move quickly across the capillary walls.
The capillaries are so thin that oxygen and carbon dioxide can pass through easily. This makes it simple for gases to move between the alveolar air and the bloodstream.
Gas exchange in the pulmonary capillaries happens through diffusion. Oxygen from the inhaled air in the alveoli moves into the blood in the capillaries. At the same time, carbon dioxide, a waste product, moves out of the blood into the alveoli to be exhaled.
This process is driven by the concentration gradient of the gases. The movement of gases is based on their concentration.
Several factors can change how well gas exchange works in the pulmonary capillary network. These include the thickness of the capillary walls, the surface area available for exchange, and the concentration gradient of the gases.
Certain conditions, like pulmonary edema or fibrosis, can make gas exchange harder. These conditions can change the thickness of the capillary walls, the surface area, and the concentration gradient of the gases.
| Factor | Effect on Gas Exchange |
|---|---|
| Capillary Wall Thickness | Increased thickness reduces gas exchange efficiency |
| Surface Area | Reduced surface area decreases gas exchange |
| Concentration Gradient | Steeper gradient enhances gas exchange |
To understand the pulmonary arterial system, we use different visualization techniques. These methods help us see how the pulmonary arteries work. They are key to our breathing health.
Diagrams and labeled images show the pulmonary arteries, bronchi, and veins. They help us see how they connect. For example, a diagram of the pulmonary artery shows how it splits into right and left arteries. This supplies blood to each lung.
Imaging like CT and MRI helps us see the pulmonary arteries. These methods give us detailed pictures. They help spot problems like pulmonary embolism or hypertension. The pulmonary artery image from these scans shows the arteries’ size and shape.
| Imaging Technique | Advantages | Applications |
|---|---|---|
| CT Scan | High-resolution images, quick scanning time | Diagnosing pulmonary embolism, assessing pulmonary artery size |
| MRI | No radiation, detailed soft tissue imaging | Evaluating pulmonary artery anatomy, assessing blood flow |
3D modeling has changed medical education. It lets us see the pulmonary arteries in detail. Educational tools with 3D models help students and professionals learn better. These models can be rotated to show different views, helping us understand the anatomy.
The pulmonary artery system is key to our breathing health. It carries blood from the heart to the lungs for oxygen. We’ve looked at how these arteries work and why they’re so important for our health.
These arteries are vital for getting blood oxygenated. This is essential for our body’s needs. Knowing how they function helps us understand our respiratory system better.
Understanding the pulmonary artery system shows us how amazing breathing is. These arteries are essential for life. Keeping them working well is critical for our health.
The pulmonary artery’s main job is to carry blood from the heart to the lungs. This blood is deoxygenated and needs oxygen.
The pulmonary trunk is about 5 cm long and 2-3 cm wide.
The pulmonary trunk divides into the right and left pulmonary arteries. These supply the lungs. They then branch into smaller arteries.
Pulmonary circulation moves deoxygenated blood to the lungs and back to the heart. Systemic circulation sends oxygenated blood to the body and returns deoxygenated blood to the heart.
The right pulmonary artery carries deoxygenated blood to the right lung. It’s key for the lung’s oxygenation.
Lobar arteries branch off the pulmonary arteries. They supply blood to lung lobes. This helps with gas exchange.
Pulmonary arterioles control blood flow through hypoxic vasoconstriction. This directs blood to areas with more oxygen.
The pulmonary capillary network is where gas exchange happens. Oxygen is absorbed, and carbon dioxide is removed.
You can see the pulmonary arterial system through diagrams and images. Radiological imaging and 3D models also help.
Knowing the pulmonary artery system is key for diagnosing and treating heart and lung issues. It’s vital for breathing and heart health.
Subscribe to our e-newsletter to stay informed about the latest innovations in the world of health and exclusive offers!