pulmonary circulation


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pulmonary

 [pul´mo-ner″e]
1. pertaining to the lungs; called also pulmonic and pneumonic.
2. pertaining to the pulmonary artery.
pulmonary acid aspiration syndrome a disorder produced as a complication of inhalation of gastric contents; it may progress to a syndrome resembling acute respiratory distress syndrome.
pulmonary alveolar proteinosis a disease of unknown etiology marked by chronic filling of the alveoli with a proteinaceous, lipid-rich, granular material consisting of surfactant and the debris of necrotic cells. Some patients have a history of exposure to irritating dusts or fumes. The condition is treated by whole lung lavage with balanced salt solution; most patients need repeated lavage.
pulmonary artery the large artery originating from the superior surface of the right ventricle of the heart and carrying deoxygenated blood to the lungs for oxygenation; it starts as the pulmonary trunk, which divides between the fifth and sixth thoracic vertebrae to form the right pulmonary artery that enters the right lung and the left pulmonary artery that enters the left lung. See Appendix 3-1.
pulmonary circulation the circulation of blood to and from the lungs. Unoxygenated blood from the right ventricle flows through the right and left pulmonary arteries to the right and left lungs. After entering the lungs, the branches subdivide, finally emerging as capillaries which surround the alveoli and release the carbon dioxide in exchange for a fresh supply of oxygen. The capillaries unite gradually and assume the characteristics of veins. These veins join to form the pulmonary veins, which return the oxygenated blood to the left atrium. See also circulatory system.
pulmonary function tests tests used to evaluate lung mechanics, gas exchange, pulmonary blood flow, and blood gases and pH. They are used to evaluate patients in the diagnosis of pulmonary disease, assessment of disease development, or evaluation of the risk of pulmonary complications from surgery.
Lung Volumes and Capacities. The total lung capacity (TLC) is divided into four volumes. The tidal volume (VT) is the volume inhaled or exhaled in normal quiet breathing. The inspiratory reserve volume (IRV) is the maximum volume that can be inhaled following a normal quiet inhalation. The expiratory reserve volume (ERV) is the maximum volume that can be exhaled following a normal quiet exhalation. The residual volume (RV) is the volume remaining in the lungs following a maximal exhalation. The vital capacity (VC) is the maximum volume that can be exhaled following a maximal inhalation; VC = IRV + VT + ERV. The inspiratory capacity (IC) is the maximum volume that can be inhaled following a normal quiet exhalation; IC = IRV + VT. The functional residual capacity (FRC) is the volume remaining in the lungs following a normal quiet exhalation; FRC = ERV + RV.

The vital capacity and its components are measured using a spirometer, which measures the volumes of air inhaled and exhaled. The functional residual capacity is usually measured by the helium dilution method using a closed spirometry system. A known amount of helium is introduced into the system at the end of a normal quiet exhalation. When the helium equilibrates throughout the volume of the system, which is equal to the FRC plus the volume of the spirometer and tubing, the FRC is determined from the helium concentration. This test may underestimate the FRC of patients with emphysema. The FRC can be determined quickly and more accurately by body plethysmography. The residual volume and total lung capacity are determined from the functional reserve capacity.
Forced Vital Capacity (FVC). In the forced vital capacity maneuver, the patient exhales as forcefully and rapidly as possible, beginning at maximal exhalation. Several parameters are determined from the spirogram. The forced vital capacity is the total volume of air exhaled during the maneuver; it is normally equal to the vital capacity. The forced expiratory volume (FEV) is the volume expired during a specified time period from the beginning of the test. The times used are 0.5, 1, 2, and 3 seconds; corresponding parameters are FEV0.5, FEV1.0, FEV2.0, and FEV3.0. The maximal expiratory flow is the slope of the line connecting the points where 200 ml and 1200 ml have been exhaled; it is also called FEF200–1200 (forced expiratory flow). The maximal midexpiratory flow is the slope of the line connecting the points where 25 per cent and 75 per cent of the forced vital capacity have been exhaled; it is also called FEF25–75%.
Maximal Voluntary Ventilation (MVV). This is the maximal volume of air that can be breathed by the patient, expressed in liters per minute; it was formerly called maximal breathing capacity. The patient breathes as rapidly and deeply as possible for 12 to 15 seconds and the volume exhaled is determined by spirometry.
Predicted Values. Because the results of pulmonary function tests vary with size and age, the normal values are calculated using prediction equations or nomograms, which give the normal value for a specific age, height, and sex. The prediction equations are derived using linear regression on the data from a population of normal subjects. The observed values are usually reported as a percentage of the predicted value.
Interpretation. These tests provide evidence of impairment of ventilatory function; they do not point to specific disease processes. Abnormal test results may show either an obstructive or a restrictive pattern; sometimes both are present.
The Obstructive Pattern. This pattern occurs when there is airway obstruction from any cause, as in asthma, bronchitis, emphysema, or advanced bronchiectasis; these conditions are grouped together in the nonspecific term chronic obstructive pulmonary disease. In this pattern, the residual volume is increased and the PV/TLC ratio is markedly increased. Owing to increased airway resistance, the flow rates are decreased. The FEV/FVC ratios, maximal midexpiratory flow, and maximal expiratory flow are all decreased; FEV1.0/FVC is less than 75 per cent.
The Restrictive Pattern. This pattern occurs when there is a loss of lung tissue or when lung expansion is limited as a result of decreased compliance of the lung or thorax or of muscular weakness. This pattern occurs in conditions such as pectus excavatum, myasthenia gravis, diffuse idiopathic interstitial fibrosis, and space-occupying lesions (tumors, effusions). The vital capacity and forced vital capacity are less than 80 per cent of the predicted value, but the FEV/FVC ratios are normal. The total lung capacity is decreased and the RV/TLC ratio is normal.
pulmonary vein any of the four large veins (two right and two left branches) that carry oxygenated blood from the lungs to the left atrium of the heart. See anatomic Table of Veins in the Appendices.

pul·mo·nar·y cir·cu·la·tion

the passage of blood from the right ventricle through the pulmonary artery to the lungs and back through the pulmonary veins to the left atrium.
Synonym(s): lesser circulation

pulmonary circulation

Etymology: L, pulmoneus, lungs, circulare
the blood flow through the network of vessels between the heart and the lungs for the oxygenation of blood and removal of carbon dioxide. Also called lesser circulation.

pul·mo·nar·y cir·cu·la·tion

(pulmŏ-nar-ē sĭrkyū-lāshŭn)
The passage of blood from the right ventricle through the pulmonary artery to the lungs and back through the pulmonary veins to the left atrium.
Enlarge picture
PULMONARY CIRCULATION

pulmonary circulation

The flow of blood from the right ventricle of the heart to the lungs for exchange of oxygen and carbon dioxide in the pulmonary capillaries, then through the pulmonary veins to the left atrium. See: illustration
See also: circulation

pul·mo·nar·y cir·cu·la·tion

(pulmŏ-nar-ē sĭrkyū-lāshŭn)
Passage of blood from right ventricle through pulmonary artery to lungs and back through pulmonary veins to left atrium.

circulation

movement in a regular or circuitous course, returning to the point of origin, as the circulation of the blood through the heart and blood vessels. See also circulatory system.

antegrade circulation
circulation in the normal direction of flow.
artificial circulation
is maintained in cardiopulmonary arrest by cardiac compression.
collateral circulation
circulation carried on through secondary channels after obstruction of the principal channel supplying the part.
coronary circulation
that within the coronary vessels, which supply the muscle of the heart.
cutaneous circulation
cutaneous vessels are innervated by sympathetic adrenergic vasoconstrictor fibers; vasodilation is an important mechanism for losing heat after the body has been warmed.
enterohepatic circulation
the cycle in which bile salts and other substances excreted by the liver in the bile are absorbed by the intestinal mucosa and returned to the liver via the portal circulation.
extracorporeal circulation
circulation of blood outside the body, as through a hemodialyzer or an extracorporeal circulatory support unit.
fetal circulation
circulation of blood through the body of the fetus and to and from the placenta through the umbilical cord. See also fetal circulation.
hepatic circulation
includes the hepatic arterial blood supply and the supply from the portal vein; drainage is via the hepatic veins to the caudal vena cava.
lymph circulation
see lymph.
maternal circulation
the circulation of the dam during pregnancy, including especially that of the uterus.
micro-circulation
neonatal circulation
circulation in the newborn immediately after birth; the umbilical vessels contract forcing blood into the fetal veins; the foramen ovale closes, the ductus arteriosus narrows and eventually closes at day 1 to 2 after birth.
ocular circulation
consists of the uveal and retinal blood vessels supported by the aqueous humor and vitreous body.
placental circulation
consists of the umbilical arteries, the vessels of the placenta proper and the umbilical veins; approximates the fetal corporeal circulation in volume.
portal circulation
a general term denoting the circulation of blood through larger vessels from the capillaries of one organ to those of another; applied especially to the passage of blood from the gastrointestinal tract, pancreas and spleen through the portal vein to the liver.
pulmonary circulation
the flow of blood from the right ventricle through the pulmonary artery to the lungs, where carbon dioxide is exchanged for oxygen, and back through the pulmonary vein to the left atrium. See also pulmonary circulation.
splenic circulation
flow of blood through the splenic artery and arterioles to either the capillaries, e. g. white pulp, or the highly permeable sinuses of the red pulp. Splenic venous blood drains into the portal vein and passes through the liver before re-entering the general circulation.
systemic circulation
the flow of blood from the left ventricle through the aorta, carrying oxygen and nutrient material to all the tissues of the body, and returning through the superior and inferior venae cavae to the right atrium.
circulation time
the time required for blood to flow between two given points. It is determined by injecting a substance into a vein and then measuring the time required for it to reach a specific site.

pulmonary

pertaining to the lungs, or to the pulmonary artery. See also lung.

pulmonary abscess
causes a syndrome of chronic toxemia, cough, loss of body weight. Careful auscultation may elicit squeaky rales around the lesions. See also caudal vena caval thrombosis, aspiration pneumonia.
pulmonary acinus
basic structural unit of the lung parenchyma; the gas exchange unit, supplied by a single terminal bronchiole and includes branches of the terminal bronchiole, alveolar ducts, alveolar sacs, alveoli and associated blood vessels. A pulmonary lobule consists of many acini.
pulmonary agenesis
incompatible with life; found only in fetal or neonatal necropsy specimens.
pulmonary alveolar microlithiasis
see microlithiasis alveolaris pulmonum.
pulmonary alveolar parenchyma
include epithelial cells (pneumonocytes or pneumocytes), alveolar capillary endothelial cells, and interstitial cells (fibroblasts) and alveolar macrophages.
pulmonary alveolar proteinosis
a disease of unknown etiology marked by chronic filling of the alveoli with a proteinaceous, lipid-rich, granular material consisting of surfactant and the debris of necrotic cells.
pulmonary arteriopathy
pulmonary artery wedge pressure
see wedge pressure.
pulmonary atelectasis
pulmonary bed
the network of capillaries in lung tissue.
pulmonary calcinosis
see microlithiasis alveolaris pulmonum.
pulmonary calculus
see bronchial calculus.
pulmonary carcinomatosis
see ovine pulmonary adenomatosis (below).
pulmonary circulation
the circulation of blood to and from the lungs. Deoxygenated blood from the right ventricle flows through the right and left pulmonary arteries to the right and left lung. After entering the lungs, the branches subdivide, finally emerging as capillaries which surround the alveoli and release the carbon dioxide in exchange for oxygen. The capillaries unite gradually and assume the characteristics of veins. These veins join to form the pulmonary veins, which return the oxygenated blood to the left atrium. See also circulatory system.
pulmonary compliance
a measure of the ability of the lung to distend in response to pressure without disruption. Expressed as the unit volume of change in the lung per unit of pressure. Compliance or distensibility of the lung is increased in conditions such as emphysema in which the lung distends more readily, and is decreased in fibrotic conditions in which the lung distends with difficulty. See also compliance.
pulmonary congestion
caused by engorgement of the pulmonary vascular bed and it may precede pulmonary edema when the intravascular fluid escapes into the parenchyma and the alveoli. There is a loss of air space and the development of respiratory embarrassment.
pulmonary cysts
may be congenital or acquired, caused by trauma, parasites (Paragonimus spp.), or associated with bronchiectasis. Rarely, metastatic tumors cavitate forming cysts.
pulmonary defense mechanisms
include aerodynamic filtration in nasal cavities, sneezing, local nasal antibody, laryngeal and cough reflexes, mucociliary transport mechanisms, alveolar macrophages, systemic and local antibody systems.
pulmonary edema
an effusion of serous fluid into the pulmonary interstitial tissues and alveoli. Preceded by pulmonary congestion (see above). If the extravascular exudation is sufficiently severe a critical level of hypoxia may be reached. The breathing will then be labored, the normal breath sounds on auscultation may be absent, and a frothy nasal discharge, often blood-tinged, may appear. At this stage the animal's life is about to terminate.
pulmonary embolus
obstruction of the pulmonary artery or one of its branches by an embolus. The embolus usually is a blood clot swept into circulation from a large peripheral vein.
Signs vary greatly, depending on the extent to which the lung is involved. Simple, uncomplicated embolism produces such cardiopulmonary signs as dyspnea, tachypnea, persistent cough, pleuritic pain and hemoptysis. On rare occasions the cardiopulmonary signs may be acute, occurring suddenly and quickly producing cyanosis and shock. A septic embolus can lead to local pulmonary abscess or an extension to pneumonia as in caudal vena caval syndrome. See also caudal vena caval thrombosis, pulmonary abscess (above).
pulmonary eosinophilic granulomatosis
a lesion common in heartworm disease; eosinophiles and neutrophils surround trapped microfilariae causing nodules as large as 3 inches diameter. May be preceded by lesions of allergic pneumonitis.
exercise-induced pulmonary hemorrhage
traces of blood can be found in about 60% of horses after racing. Less than 1% of these bleed from the nostrils. See also epistaxis.
pulmonary function tests
tests used to evaluate lung mechanics, gas exchange, pulmonary blood flow and blood acid-base balance. Pulmonary function testing is used to detect emphysema and chronic obstructive bronchitis at an early stage.
pulmonary hemorrhage
as distinct from hemothorax, is recognized because of a syndrome of dyspnea, increased lung density radiographically, and hemorrhagic anemia. If a large vessel ruptures into an abscess cavity there is usually a massive hemoptysis and instant death. Frothy blood-stained nasal discharge is an indication of pulmonary edema rather than of pulmonary hemorrhage. See also exercise-induced pulmonary hemorrhage (above).
pulmonary horse sickness
the predominantly pulmonary form of african horse sickness.
pulmonary hypertrophic osteoarthropathy
see hypertrophic osteopathy.
pulmonary hypoplasia
a congenital defect resulting in decreased lung development.
pulmonary infarction
see pulmonary infarction, pulmonary embolus (above).
pulmonary infiltration with eosinophilia (PIE)
pulmonary malformation
includes accessory lungs, pulmonary hypoplasia, pulmonary agenesis, congenital pulmonary cysts, endodermal heteroplasia, respiratory distress syndrome, neonatal maladjustment syndrome, immotile cilia syndrome.
pulmonary mycoses
includes aspergillosis, mortierellosis, blastomycosis, cryptococcosis, coccidioidomycosis.
pulmonary neoplasm
many types are recorded in all species but the prevalence is very low in food animals. A common site for metastases in companion animals. Characterized clinically by decreased exercise tolerance, progressive dyspnea, chronic cough and emaciation. Most diagnoses result from radiographic examination of the thorax for secondary growths.
neurogenic pulmonary edema
results from head trauma, central nervous system lesions and toxins, which may cause increased pulmonary blood pressure and alteration to sympathetic innervation leading to fluid leakage from vessels.
overriding pulmonary artery
see overriding pulmonary artery.
ovine pulmonary adenomatosis
a very chronic progressive pneumonia of sheep and goats caused by a retrovirus. Dyspnea, emaciation and a profuse nasal discharge are the cardinal signs, but coughing is not evident. The disease is always fatal. It is of great importance if it occurs in flocks that are housed for long periods. Characteristically the extensive lung involvement includes large areas of neoplastic tissue. Called also jaagsiekte, pulmonary carcinomatosis.
pulmonary patterns
see alveologram pattern, bronchial pattern.
re-expansion pulmonary edema
edema, emphysematous bullae and serosanguinous fluid in the airways with generalized pulmonary capillary endothelial damage; associated with chronic pulmonary collapse and removal of pleural effusions or pneumothorax with rapid re-expansion.
pulmonary rupture
traumatic, especially when there is rib fracture, or spontaneous due to coughing and a weak parenchyma. The most common cause of pneumothorax.
pulmonary thromboembolic disease
thromboembolism causing blockage of large sections of the pulmonary vascular bed will result in at least temporary severe dyspnea. It may also lead to right heart congestive failure, i.e. cor pulmonale.
pulmonary thrombosis
pulmonary valve
the pocket-like structure that guards the orifice between the right ventricle and the pulmonary artery.
pulmonary valve stenosis
causes right ventricular hypertrophy and a poststenotic dilatation of the pulmonary artery. There is a systolic murmur and thrill on the left side of the chest. A common congenital defect in dogs.
pulmonary vein
the large vein (right and left branches) that carries oxygenated blood from the lungs to the left atrium of the heart.
pulmonary wedge pressure
see wedge pressure.
References in periodicals archive ?
Effect of chronic vanadate administration on pulmonary circulation in the rat Respiration 49:68-72.
This extensive system, called the pulmonary circulation, filters clots, fat particles, and cellular debris from the bloodstream.
When the left ventricle experiences systolic dysfunction, blood backs up into the pulmonary circulation, elevates pulmonary vascular pressures, and produces pulmonary congestion.
Not just the small coronary arteries are affected, but small arteries everywhere else in the body, too, including the digits, pulmonary circulation, and the kidneys.
Subsequent chapters detail tests of lung function, alveolar ventilation, pulmonary circulation, ventilation and profusion, oxygen and carbon dioxide transport, acid-base balance and arterial blood-gas interpretation, control of respiration, nonrespiratory function, and special circumstances.
3) Nevertheless, it is possible that atelectasis led to hypoxemic vasoconstriction of the pulmonary circulation, which, combined with diversion of the cardiac output to the right lung, led to increase in pulmonary hypertension sufficient to pressure overload the right ventricle, resulting in the inferior ST-segment changes.
The right ventricle continues to function as a pump for pulmonary circulation except when the right-sided portion of the Thoratec pump is in use.
The study protocol involved baseline assessment of fetal pulmonary circulation, following which 60% oxygen was administered by rebreathing mask to the mothers.
These changes in pulmonary circulation and alveoli lead to mismatching of ventilation and perfusion, and therefore provide high-risk conditions suitable for recurrent respiratory infections.
Aims of supportive therapy were to optimise pulmonary circulation by reducing pulmonary vascular resistance with >80% oxygen, moderate hyperventilation (to a [P.
The latter, recognising that large clots within the pulmonary circulation may be rapidly fatal, attempted the first pulmonary embolectomies.