Pulmonary Circulation Flashcards
Regarding the bronchial arteries (true or false):
The bronchial arteries arise from the pulmonary arteries
False. The bronchial arteries arise from the thoracic aorta and carry oxygenated blood to the bronchial tree.
Regarding the bronchial arteries (true or false):
The bronchial arteries are thicker-walled than the pulmonary arteries
True. Their walls are similarly constructed to other systemic arteries, as opposed to the pulmonary arteries which are thinner-walled.
Regarding the bronchial arteries (true or false):
The bronchial arteries carry oxygenated blood
True
Regarding the bronchial arteries (true or false):
The bronchial arteries drain partly into the left atrium via bronchial veins
True. Some of their drainage is into the left atrium, so the left side of the heart has an increased cardiac output when compared to the right side of the heart.
Regarding the bronchial arteries (true or false):
The bronchial arteries account for the decreased cardiac output of the left heart compared to the right
False. Some of their drainage is into the left atrium, so the left side of the heart has an increased cardiac output when compared to the right side of the heart.
Regarding pulmonary vascular resistance (PVR) (true or false):
PVR is higher than systemic vascular resistance
False. PVR is much lower than systemic vascular resistance: it is only about 10% of the systemic value, at about 160 dyn/sec-1/cm-5 in health.
Regarding pulmonary vascular resistance (PVR) (true or false):
PVR is increased by hypoxia
True. Hypoxic pulmonary vasoconstriction is a well described physiological response.
Regarding pulmonary vascular resistance (PVR) (true or false):
PVR is approximately 10 dyn.sec-1.cm-5 in the healthy state
False. PVR is much lower than systemic vascular resistance: it is only about 10% of the systemic value, at about 160 dyn/sec-1/cm-5 in health (so not quite as low as 10 dyn.sec-1.cm-5).
Regarding pulmonary vascular resistance (PVR) (true or false):
PVR is decreased by low lung volumes
False. PVR is increased by both low and high lung volumes, but as a result of two different processes. The vessels are narrowed by smooth muscle tone in the former, whilst they are stretched out and also narrowed in the latter.
Regarding pulmonary vascular resistance (PVR) (true or false):
PVR is increased by high lung volumes
True. PVR is increased by both low and high lung volumes, but as a result of two different processes. The vessels are narrowed by smooth muscle tone in the former, whilst they are stretched out and also narrowed in the latter.
In the context of a person who is standing up (true or false):
Alveolar pressure is lower than arterial pressure at the top of the lung
False. At the top of the lung the intravascular pressures are reduced compared to the main pulmonary artery according to the hydrostatic level. Alveolar pressure therefore exceeds venous and arterial pressure.
In the context of a person who is standing up (true or false):
Arterial pressure is greater than venous pressure at the top of the lung
True. Arterial pressure is always greater than venous pressure, otherwise there would be no forward vascular flow.
In the context of a person who is standing up (true or false):
Arterial pressure is augmented by hydrostatic pressure at the top of the lung
False. In the lower (not higher) part of the lung, arterial pressure is augmented by the hydrostatic pressure and exceeds alveolar pressure during the entire cardiac cycle, which produces continuous blood flow.
In the context of a person who is standing up (true or false):
Arterial pressure is always greater than venous pressure
True. Arterial pressure is indeed always greater than venous pressure, otherwise there would be no forward vascular flow.
In the context of a person who is standing up (true or false):
Blood flow is increased in the mid and lower parts of the lungs
True. In the lower part of the lung, arterial pressure is augmented by the hydrostatic pressure and exceeds alveolar pressure during the entire cardiac cycle, which produces continuous blood flow. Because of this phenomenon, blood flow is increased in the mid and lower parts of the lung.
