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    From Cardiovascular System

    Visceral Layer (Epicardium)
    Covers the external surface of the heart.
    Superior Vena Cava
    Returns deoxygenated blood from upper body.
    External Iliac Veins
    Drain lower limbs and join internal iliac veins.
    Cephalic Veins
    Superficial veins of the lateral upper limb.
    Tricuspid Valve
    Valve between the right atrium and right ventricle.
    Anterior Interventricular Branch
    Supplies anterior interventricular septum (LAD).
    Right Ventricle
    Pumps blood to the lungs via pulmonary artery.
    Left Atrium
    Receives oxygenated blood from the lungs.
    Descending Aorta
    Portion of the aorta descending through thorax and abdomen.
    Axillary Veins
    Drain the upper limbs and join with subclavian veins.
    Aortic Valve
    Valve between left ventricle and aorta.
    Median Cubital Vein
    Connects cephalic and basilic veins at the elbow.
    Radial Arteries
    Supply the lateral aspect of the forearm and hand.
    Left Inferior Pulmonary Vein
    Returns oxygenated blood from left lung.
    Right Inferior Pulmonary Vein
    Returns oxygenated blood from right lung.
    Mitral Valve
    Valve between the left atrium and left ventricle.
    Pericardium
    Double-walled sac containing the heart and the roots of the great vessels.
    External Carotid Artery
    Supplies blood to the face and scalp.
    Trabeculae Carneae
    Irregular muscular columns on the walls of the ventricles.
    Small Cardiac Vein
    Drains right atrium and ventricle.
    Interatrial Septum
    Wall separating the left and right atria.
    External Iliac Arteries
    Continue into the legs as femoral arteries.
    Anterior Cardiac Veins
    Drain directly into the right atrium.
    Serous Pericardium
    Inner layer of the pericardium consisting of parietal and visceral layers.
    Internal Iliac Veins
    Drain pelvic organs.

    Right Pulmonary Artery

    Reviewed by our medical team

    Carries blood to right lung.

    Overview

    The right pulmonary artery is one of the two branches of the pulmonary trunk that transports deoxygenated blood from the right ventricle to the right lung. Despite being an artery, it carries oxygen-poor blood — a unique feature of pulmonary arteries compared to systemic arteries. The right pulmonary artery plays a central role in pulmonary circulation by delivering blood to the right lung for oxygenation.

    Location

    The right pulmonary artery arises from the pulmonary trunk at the level of the sternal angle (around T5–T6 vertebrae). It travels:

    • Horizontally to the right, passing posterior to the ascending aorta and superior vena cava

    • Anterior to the right main bronchus

    • Enters the right lung at the hilum as part of the root of the lung

    Once inside the lung, it divides into lobar and then segmental arteries to supply all regions of the right lung.

    Structure

    The right pulmonary artery is a thick-walled, elastic artery adapted for high-volume, low-pressure blood flow. It typically has:

    • Origin: Pulmonary trunk

    • Course: Longer and larger than the left pulmonary artery due to the heart's left-sided position

    • Diameter: Approximately 1.5–2.5 cm in adults

    • Wall composition: Tunica intima (endothelium), tunica media (elastic fibers and smooth muscle), and tunica adventitia

    At the hilum, the right pulmonary artery typically lies anterior to the bronchus and superior to the pulmonary veins.

    Function

    The primary function of the right pulmonary artery is to:

    • Transport deoxygenated blood from the right ventricle to the right lung

    There, the blood flows through smaller arteries, arterioles, and capillaries surrounding the alveoli, allowing gas exchange to occur. The now oxygenated blood returns to the left atrium via the right pulmonary veins.

    Physiological Role(s)

    The right pulmonary artery contributes to several physiological processes:

    • Gas exchange support: Delivers blood to alveolar capillaries for oxygen uptake and carbon dioxide release

    • Low-pressure circulation: Operates under significantly lower pressure than systemic arteries to protect delicate pulmonary capillaries

    • Dynamic flow adjustment: Can constrict or dilate in response to oxygen levels, optimizing ventilation-perfusion matching

    • Right ventricular afterload regulation: Its resistance influences right ventricular workload and output

    Clinical Significance

    The right pulmonary artery is central to several cardiopulmonary conditions and clinical procedures:

    • Pulmonary Hypertension: Increased pressure in the pulmonary arteries leads to right ventricular hypertrophy and failure. Often involves both left and right pulmonary arteries.

    • Pulmonary Embolism (PE): A clot may lodge in the right pulmonary artery, reducing blood flow to the right lung and causing hypoxia, chest pain, or sudden death.

    • Pulmonary Artery Stenosis: Narrowing of the right pulmonary artery (congenital or acquired) can cause reduced lung perfusion and right-sided pressure overload.

    • Congenital Heart Disease: Abnormal development of the right pulmonary artery may be seen in conditions like Tetralogy of Fallot or truncus arteriosus. Surgical correction is often required.

    • Right Heart Catheterization: The right pulmonary artery is a target site during catheter-based hemodynamic studies to measure pulmonary artery pressures and cardiac output.

    • Imaging: CT pulmonary angiography and echocardiography are critical tools for assessing right pulmonary artery size, flow, and pathology.

    Timely diagnosis and treatment of right pulmonary artery-related conditions are essential to prevent complications such as hypoxemia, pulmonary infarction, or right heart failure.

    Did you know? The aorta, the largest artery in the body, carries blood from the heart to the rest of the body.