Term
| Where is vascular pressure greater, systemic or pulmonary circulation? |
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Definition
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Term
| How does pulmonary circulation act as a blood filter? |
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Definition
| there are more capillaries in pulmonary circulation than are required for gas exchange at rest, so some of these can trap particles which would later be removed by enzymes, macrophages, lymphatic system etc |
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Term
| Which arteries are elastic and which are muscular? |
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Definition
bronchial arteries are elastic
smaller bronchiole arteries & alveolar ducts are muscular |
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Term
True or False
Most resistance to pulmonary blood flow is in the capillaries |
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Definition
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Term
| What passive factors affect pulmonary vascular pressure? |
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Definition
Cardiac Pressure
Pulmonary inflation
inhalation = dilated arteries/veins, compressed capillaries
exhalation = compressed extra-alveolar aa/vv dilated capillaries |
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Term
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Definition
| pulmonary vascular resistance |
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Term
| How does distention & recruitment affect PVR? |
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Definition
-there are unused capillaries at rest
-increased cardiac output = increased pulmonary arterial pressure
-pulmonary vessels become distended, triggering release of NO which leads to vasodilation & recruitment of unused capillaries |
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Term
| How does hematocrit influence PVR? |
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Definition
| increased hematocrit count = increased blood viscosity = increase PVR |
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Term
| Which portion of the lung is better perfused, the dorsal or ventral portion? |
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Definition
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Term
| What passive influences affect pulmonary vascular resistance (PVR)? |
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Definition
-distension & recruitment
-increased hematocrit |
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Term
| Which animals have the most vascular smooth muscle in small pulmonary arteries? |
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Definition
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Term
| What active influences act on pulmonary vascular resistance? |
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Definition
Neural & hormonal factors
Pulmonary alveolar oxygen concentration |
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Term
| What hormones cause vasoconstriction of small pulmonary arteries? |
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Definition
-stimulation of a1 adrenergic receptors
-inflammatory mediators (histamine, seratonin, bradykinin)
-PGF2alpha |
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Term
| What hormones cause vasodilation of small pulmonary arteries? |
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Definition
-stimulation of b2-adrenergic receptors
-nitric oxide
-PGE2 & PGI2 |
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Term
| How does pulmonary alveolar oxygen concentration inluence PVR? |
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Definition
| decreased oxygen in alveoli = decreased oxygen in arterioles = vasoconstriction to redirect blood to better ventilated areas |
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Term
True or False
Bronchial circulation is not a component of pulmonary circulation |
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Definition
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Term
True or False
Bronchial circulation receives direct cardiac output from the left side of the heart (systemic circulation) |
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Definition
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Term
| What are bronchopulomonary anastomoses? |
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Definition
| junctions between bronchial & pulmonary arteries/capillaries |
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Term
| What is the role of bronchopulmonary ansatomoses? |
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Definition
| provides back-up blood supply via pulmonary circuits in the event that a bronchial vessel becomes occluded, or vice-versa |
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Term
| How does high altitude affect ventilation & circulation? |
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Definition
-high alt = lower oxygen concentrations
-leads to hyperventilation = less PCO2
-can lead to respiratory alkalosis |
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Term
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Definition
accumulation of fluid in the alveoli due decreased plasma oncotic pressure, increased capillary pressure, damaged capillary endothelium etc
(basically anything that would cause fluid to leave circulation & accumulate in the alveoli) |
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