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Pulmonary embolism is blood clots occurring in the lungs. Restricted blood flow in the pulmonary circulation results in alveoli ventilated but not perfused, thus, increasing the V/Q ratio and decreasing gas exchange. It can cause hypoxemia(low oxygen level) and damage part of the lung, which may be treated with anticoagulants.
Oxygen-deprived blood from the superior and inferior vena cava enters the right atrium of the heart and flows through the tricuspid valve (right atrioventricular valve) into the right ventricle, from which it is then pumped through the pulmonary semilunar valve into the pulmonary artery to the lungs. Gas exchange occurs in the lungs, whereby CO ...
Oxygenated blood leaves the lungs through pulmonary veins, which return it to the left part of the heart, completing the pulmonary cycle. [3] [6] This blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. [3] [6] From the left ventricle, the blood passes through the aortic valve to the aorta.
This blood gas barrier is extremely thin (in humans, on average, 2.2 μm thick). It is folded into about 300 million small air sacs called alveoli [23] (each between 75 and 300 μm in diameter) branching off from the respiratory bronchioles in the lungs, thus providing an extremely large surface area (approximately 145 m 2) for gas exchange to ...
The process by which oxygen is taken in by the bloodstream is called oxygenation. Lung compliance is the capacity of the lungs to contract and expand. The obstruction of airflow via the respiratory tract is known as airway resistance. The amount of ventilated air that is not involved in gas exchange is known as dead-space ventilation. [5] [tone]
In the oxygen-rich capillaries of the lung, this property causes the displacement of carbon dioxide to plasma as low-oxygen blood enters the alveolus and is vital for alveolar gas exchange. The general equation for the Haldane Effect is: H + + HbO 2 ⇌ H + Hb + O 2; However, this equation is confusing as it reflects primarily the Bohr effect.
The process might initially seem counterintuitive, as low oxygen levels might theoretically stimulate increased blood flow to the lungs to increase gas exchange. However, the purpose of HPV is to distribute bloodflow regionally to increase the overall efficiency of gas exchange between air and blood.
The opposite process occurs in the pulmonary capillaries of the lungs when the PO 2 rises and PCO 2 falls, and the Haldane effect occurs (release of CO 2 from hemoglobin during oxygenation). This releases hydrogen ions from hemoglobin, increases free H + concentration within RBCs, and shifts the equilibrium towards CO 2 and water formation from ...