Search results
Results from the WOW.Com Content Network
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.
The peripheral feeding veins do not follow the bronchial tree. They run between the pulmonary segments from which they drain the blood. [1] At the root of the lung, the right superior pulmonary vein lies in front of and a little below the pulmonary artery; the inferior is situated at the lowest part of the lung hilum.
The blood flow through the bird lung is at right angles to the flow of air through the parabronchi, forming a cross-current flow exchange system (Fig. 19). [ 44 ] [ 46 ] [ 49 ] The partial pressure of oxygen in the parabronchi declines along their lengths as O 2 diffuses into the blood.
In a compensated state, blood vessels supplying less-ventilated areas of the lung may selectively contract, to redirect the blood to areas of the lungs which are better ventilated. However, in a chronic context, and if the lungs are not well ventilated generally, this mechanism can result in pulmonary hypertension , overloading the right ...
Instead of blood flowing through the pulmonary artery to the lungs, the sphincter may be contracted to divert this blood flow through the incomplete ventricular septum into the left ventricle and out through the aorta. This means the blood flows from the capillaries to the heart and back to the capillaries instead of to the lungs.
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.
By redirecting blood flow from poorly-ventilated lung regions to well-ventilated lung regions, HPV is thought to be the primary mechanism underlying ventilation/perfusion matching. [ 1 ] [ 2 ] The process might initially seem counterintuitive, as low oxygen levels might theoretically stimulate increased blood flow to the lungs to increase gas ...
As a result, the heart has a hard time pumping blood through the lungs, and the blood vessels eventually undergoes fibrosis. The increased workload on the heart causes hypertrophy of the right ventricle, which leads less blood being pump through the lungs and decreased blood to the left side of the heart. As a result of all of this, the left ...