An embolism is the lodging of an embolus, a blockage-causing piece of material, inside a blood vessel. The embolus may be a blood clot (thrombus), a fat globule, a bubble of air or other gas, amniotic fluid, or foreign material. An embolism can cause partial or total blockage of blood flow in the affected vessel. Such a blockage may affect a part of the body distant from the origin of the embolus. An embolism in which the embolus is a piece of thrombus is called a thromboembolism.
An embolus is an unattached mass that travels through the bloodstream and is capable of creating blockages. When an embolus occludes a blood vessel, it is called an embolism or embolic event. There are a number of different types of emboli, including blood clots, cholesterol plaque or crystals, fat globules, gas bubbles, and foreign bodies, which can result in different types of embolisms.
A thrombus, colloquially called a blood clot, is the final product of the blood coagulation step in hemostasis. There are two components to a thrombus: aggregated platelets and red blood cells that form a plug, and a mesh of cross-linked fibrin protein. The substance making up a thrombus is sometimes called cruor. A thrombus is a healthy response to injury intended to stop and prevent further bleeding, but can be harmful in thrombosis, when a clot obstructs blood flow through healthy blood vessels in the circulatory system.
The pleural cavity, pleural space, or interpleural space is the potential space between the pleurae of the pleural sac that surrounds each lung. A small amount of serous pleural fluid is maintained in the pleural cavity to enable lubrication between the membranes, and also to create a pressure gradient.
Pulmonary embolism (PE) is a blockage of an artery in the lungs by a substance that has moved from elsewhere in the body through the bloodstream (embolism). Symptoms of a PE may include shortness of breath, chest pain particularly upon breathing in, and coughing up blood. Symptoms of a blood clot in the leg may also be present, such as a red, warm, swollen, and painful leg. Signs of a PE include low blood oxygen levels, rapid breathing, rapid heart rate, and sometimes a mild fever. Severe cases can lead to passing out, abnormally low blood pressure, obstructive shock, and sudden death.
Pulmonary heart disease, also known as cor pulmonale, is the enlargement and failure of the right ventricle of the heart as a response to increased vascular resistance or high blood pressure in the lungs.
An air embolism, also known as a gas embolism, is a blood vessel blockage caused by one or more bubbles of air or other gas in the circulatory system. Air can be introduced into the circulation during surgical procedures, lung over-expansion injury, decompression, and a few other causes. In flora, air embolisms may also occur in the xylem of vascular plants, especially when suffering from water stress.
A pulmonary artery is an artery in the pulmonary circulation that carries deoxygenated blood from the right side of the heart to the lungs. The largest pulmonary artery is the main pulmonary artery or pulmonary trunk from the heart, and the smallest ones are the arterioles, which lead to the capillaries that surround the pulmonary alveoli.
In human anatomy, the bronchial arteries supply the lungs with oxygenated blood, and nutrition. Although there is much variation, there are usually two bronchial arteries that run to the left lung, and one to the right lung, and are a vital part of the respiratory system.
Hypoxemia is an abnormally low level of oxygen in the blood. More specifically, it is oxygen deficiency in arterial blood. Hypoxemia has many causes, and often causes hypoxia as the blood is not supplying enough oxygen to the tissues of the body.
In the fetal heart, the foramen ovale, also foramen Botalli, or the ostium secundum of Born, allows blood to enter the left atrium from the right atrium. It is one of two fetal cardiac shunts, the other being the ductus arteriosus. Another similar adaptation in the fetus is the ductus venosus. In most individuals, the foramen ovale closes at birth. It later forms the fossa ovalis.
Fat embolism syndrome occurs when fat enters the blood stream and results in symptoms. Symptoms generally begin within a day. This may include a petechial rash, decreased level of consciousness, and shortness of breath. Other symptoms may include fever and decreased urine output. The risk of death is about 10%.
Lines of Zahn are a characteristic of thrombi. They have layers, with lighter layers of platelets and fibrin, and darker layers of red blood cells. They are more present on thrombi formed with faster blood flow, more so on thrombi from the heart and aorta. They are only seen on thrombi formed before death. They are named after German–
The Alveolar–arterial gradient, is a measure of the difference between the alveolar concentration (A) of oxygen and the arterial (a) concentration of oxygen. It is a useful parameter for narrowing the differential diagnosis of hypoxemia.
A pulmonary laceration is a chest injury in which lung tissue is torn or cut. An injury that is potentially more serious than pulmonary contusion, pulmonary laceration involves disruption of the architecture of the lung, while pulmonary contusion does not. Pulmonary laceration is commonly caused by penetrating trauma but may also result from forces involved in blunt trauma such as shear stress. A cavity filled with blood, air, or both can form. The injury is diagnosed when collections of air or fluid are found on a CT scan of the chest. Surgery may be required to stitch the laceration, to drain blood, or even to remove injured parts of the lung. The injury commonly heals quickly with few problems if it is given proper treatment; however it may be associated with scarring of the lung or other complications.
ST elevation refers to a finding on an electrocardiogram wherein the trace in the ST segment is abnormally high above the baseline.
Arterial embolism is a sudden interruption of blood flow to an organ or body part due to an embolus adhering to the wall of an artery blocking the flow of blood, the major type of embolus being a blood clot (thromboembolism). Sometimes, pulmonary embolism is classified as arterial embolism as well, in the sense that the clot follows the pulmonary artery carrying deoxygenated blood away from the heart. However, pulmonary embolism is generally classified as a form of venous embolism, because the embolus forms in veins. Arterial embolism is the major cause of infarction.
Myocardial infarction complications may occur immediately following a heart attack, or may need time to develop. After an infarction, an obvious complication is a second infarction, which may occur in the domain of another atherosclerotic coronary artery, or in the same zone if there are any live cells left in the infarct.
The bronchial circulation is the part of the systemic circulation that supplies nutrients and oxygen to the cells that constitute the lungs, as well as carrying waste products away from them. It is complementary to the pulmonary circulation that brings deoxygenated blood to the lungs and carries oxygenated blood away from them in order to oxygenate the rest of the body.
CT scan of a lung infarction because of chronic pulmonary embolism (white arrow). The infarcted area (black arrow) has a reverse halo sign.
