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22 Cards in this Set
- Front
- Back
Compare pulmonary versus systemic circulation.
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Pressures and resistance are much lower in the pulmonary circulation.
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Compare the following parameters in adult and fetal pulmonary circulation.
Pressure Resistance Flow |
Pressure; Adult is low
Fetal is high Resistance; Adult is low Fetal is high Flow; Adult is high Fetal is low |
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What happens to resistance as pressure in the pulmonary artery increases?
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Resistance decreass even lower because previously collapsed capillaries open up(recruitment), and individual capillary segments widen(distension)
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Where does pulmonary blood flow come from?
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Cardiac output of the right ventricle.
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What factors contribute to the large compliance of the pulmonary arterial tree?
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1. Short pulmonary arterial branches
2. All pulmonary arteries have larger diameters than their counterpart systemic aretries 3. Vessels are very thin and distensible |
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How does blood flowing through the pulmonary arteries differ from that flowing through the systemic arteries?
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Blood in the pulmonary arteries is partially deoxygenated, while that in the systemic arteries is oxygenated.
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Blood flowing through the bronchial arteries is partially deoxygenated. TRUE/FALSE
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FALSE
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What does bronchial arterial blood supply?
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Supporting tissues of the lungs including the connective tissue, septa, and large and small bronchi.
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All of the blood in the left ventricle comes from the right ventricle.
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False. Some of the blood enters the bronchial blood flow, and blood that flows through the coronary arteries enters the left side of the heart without entering the right atrium.
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At which point is the pressure in the pulmonary aretry essentially equal to the pressure in the right ventricle?
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During the systolic phase of the cardiac cycle.
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What are the average pulmonary arterial pressures?
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Systole: 25mm/Hg
Diastole: 8mm/Hg |
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How is the pulmonary wedge pressure obtained?
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Via a catheter intoduced via the systemic venous circulation(femoral vein) that is wedged in a pulmonary aretriole.
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What does the pulmonary wedge pressure estimate?
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1. Pulmonary venous pressure
2. Left atrial pressure 3. Left ventricular end diastolic pressure |
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How does gravity affect the pulmonary circulation?
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In the upright position, the apices of the lungs are above the level of the heart, while the bases are at or below it. There is a relatively marked pressure gradient in the pulmonary arteries.
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When standing, where is pulmonary blood flow the least?
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Apices
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What happens when pressure in the pulmonary artery increases/
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Resistance falls even low because of recruitment of previously collapsed capillaries and distension of existing capillary segments.
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What are some consequences of long standing pulmonary hypertension?
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Cor pulmonale and right ventricular failure.
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What is the physiologic response of the lungs to hypoxia?
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Vasoconstriction
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Why is the response to hypoxia by the lungs significant?
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It redirects blood from poorly ventilated regions to well ventilated areas.
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What changes does chronic hypoxia cause in the pulmonary circulation?
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1. Sustained pulmonary vasoconstriction
2. Increase in number of perivascular smooth muscle cells. 3. |
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Increasaed interstitial collagen is a change seen in chronic hypoxia. TRUE/FALSE
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TRUE
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How does inspiration affect venous return?
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Increases it by increasing intrapleural pressure.
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