Pulmonary Circulation Quiz

Pulmonary Circulation: Pressures, Resistance, and Oedema

• The pulmonary circulation consists of two blood supplies to the lungs: bronchial and pulmonary
• The pulmonary circulation is responsible for transporting deoxygenated blood from the right ventricle to the alveolar capillaries and returning oxygenated blood to the left atrium
• The pulmonary circuit receives the same volume of blood as the systemic circulation, but it is a low pressure system
• The pulmonary circulation has low resistance due to capillary recruitment and distension
• Oxygen is a crucial factor in pulmonary circulation and hypoxia leads to constriction, known as hypoxic pulmonary vasoconstriction
• Hypoxic pulmonary vasoconstriction shunts blood away from poorly ventilated areas and matches ventilation with perfusion
• The effect of gravity on flow causes three regions of lung perfusion: zone 1 (apex), zone 2 (middle), and zone 3 (base)
• Pulmonary oedema occurs due to an imbalance in Starling forces or failure to clear fluid, which increases the diffusion distance for oxygen and decreases lung compliance
• Major causes of pulmonary oedema are rises in pulmonary capillary pressure, high altitude causing hypoxic pulmonary vasoconstriction, and increases in pulmonary capillary permeability
• The low pressure nature of the pulmonary circulation means capillary pressure is low, and lymphatic pumping means interstitial pressure is lower
• The net filtration pressure in the pulmonary circulation is (Pc − Pi) − (πc − πi), and it is lower than in the systemic circulation
• The pulmonary circulation has limited extrinsic control, and resistance is controlled by local factors.

Pulmonary Circulation: Pressures, Resistance, and Oedema

• The pulmonary circulation consists of two blood supplies to the lungs: bronchial and pulmonary
• The pulmonary circulation is responsible for transporting deoxygenated blood from the right ventricle to the alveolar capillaries and returning oxygenated blood to the left atrium
• The pulmonary circuit receives the same volume of blood as the systemic circulation, but it is a low pressure system
• The pulmonary circulation has low resistance due to capillary recruitment and distension
• Oxygen is a crucial factor in pulmonary circulation and hypoxia leads to constriction, known as hypoxic pulmonary vasoconstriction
• Hypoxic pulmonary vasoconstriction shunts blood away from poorly ventilated areas and matches ventilation with perfusion
• The effect of gravity on flow causes three regions of lung perfusion: zone 1 (apex), zone 2 (middle), and zone 3 (base)
• Pulmonary oedema occurs due to an imbalance in Starling forces or failure to clear fluid, which increases the diffusion distance for oxygen and decreases lung compliance
• Major causes of pulmonary oedema are rises in pulmonary capillary pressure, high altitude causing hypoxic pulmonary vasoconstriction, and increases in pulmonary capillary permeability
• The low pressure nature of the pulmonary circulation means capillary pressure is low, and lymphatic pumping means interstitial pressure is lower
• The net filtration pressure in the pulmonary circulation is (Pc − Pi) − (πc − πi), and it is lower than in the systemic circulation
• The pulmonary circulation has limited extrinsic control, and resistance is controlled by local factors.

Pulmonary Circulation: Pressures, Resistance, and Oedema

• The pulmonary circulation consists of two blood supplies to the lungs: bronchial and pulmonary
• The pulmonary circulation is responsible for transporting deoxygenated blood from the right ventricle to the alveolar capillaries and returning oxygenated blood to the left atrium
• The pulmonary circuit receives the same volume of blood as the systemic circulation, but it is a low pressure system
• The pulmonary circulation has low resistance due to capillary recruitment and distension
• Oxygen is a crucial factor in pulmonary circulation and hypoxia leads to constriction, known as hypoxic pulmonary vasoconstriction
• Hypoxic pulmonary vasoconstriction shunts blood away from poorly ventilated areas and matches ventilation with perfusion
• The effect of gravity on flow causes three regions of lung perfusion: zone 1 (apex), zone 2 (middle), and zone 3 (base)
• Pulmonary oedema occurs due to an imbalance in Starling forces or failure to clear fluid, which increases the diffusion distance for oxygen and decreases lung compliance
• Major causes of pulmonary oedema are rises in pulmonary capillary pressure, high altitude causing hypoxic pulmonary vasoconstriction, and increases in pulmonary capillary permeability
• The low pressure nature of the pulmonary circulation means capillary pressure is low, and lymphatic pumping means interstitial pressure is lower
• The net filtration pressure in the pulmonary circulation is (Pc − Pi) − (πc − πi), and it is lower than in the systemic circulation
• The pulmonary circulation has limited extrinsic control, and resistance is controlled by local factors.