• venous blood
  • The multiple inert gas elimination technique (MIGET) is a medical technique used mainly in pulmonology that involves measuring the concentrations of various infused, inert gases in mixed venous blood, arterial blood, and expired gas of a subject. (wikipedia.org)
  • lungs
  • So where is the VQ ratio highest in the lungs? (cram.com)
  • Why does emphysema result in an abnormal VQ ratio in the lungs? (cram.com)
  • Because in the lungs, you're at the top of the oxygen dissociation curve, where changes in blood oxygen content don't change PO2 much. (cram.com)
  • The process might initially seem counterintuitive, as low oxygen levels might theoretically stimulate increased blood flow to the lungs to increase gas exchange. (wikipedia.org)
  • The V/Q ratio of a healthy lung is approximately equal to 0.8, as normal lungs are not perfectly matched. (wikipedia.org)
  • Let us consider some scenarios where there is a defect in ventilation and/ or perfusion of the lungs. (wikipedia.org)
  • In cases of right to left shunts more of deoxygenated blood mixes with oxygenated blood from the lungs and thus to a small extent the condition might neutralize the high A-a gradient with pure oxygen therapy. (wikipedia.org)
  • The lungs have a unique blood supply, receiving deoxygenated blood from the heart in the pulmonary circulation for the purposes of receiving oxygen and releasing carbon dioxide, and a separate supply of oxygenated blood to the tissue of the lungs, in the bronchial circulation. (wikipedia.org)
  • This can include decreased partial pressures of oxygen, problems with diffusion of oxygen in the lungs, insufficient available hemoglobin, problems with blood flow to the end tissue, and problems with breathing rhythm. (wikipedia.org)
  • concentrations
  • This has a major impact on the V/Q ratio: apex of lung - higher base of lung - lower In a subject standing in orthostatic position (upright) the apex of the lung shows higher V/Q ratio, while at the base of the lung the ratio is lower but nearer to the optimal value for reaching adequate blood oxygen concentrations. (wikipedia.org)
  • capillary
  • The gradients across the arterial segment (Pa = Ppa - Pc) and across the venous segment (Pv = Pc - Pw) of the pulmonary vasculature were defined by the computation of effective capillary pressure (Pc) obtained from the analysis of the transient decay of pulmonary artery pressure (Ppa) toward wedge pressure (Pw) after arterial occlusion. (uliege.be)
  • diastolic
  • While the presence of a coronary circulation in certain fishes decreases the reliance of the heart on P v O 2 , hypoxic bradycardia could still benefit oxygen delivery via an extended diastolic period during which peak coronary blood flow occurs. (biologists.org)
  • Due to the structural and functional characteristics of the right ventricle (thin walled chamber with low pressure, low oxygen demand and both systolic and diastolic perfusion), it is unusual to have a massive extension of the infarction and an irreversible progress. (biomedsearch.com)
  • increases
  • Thus, either ventilation (V) remains stable or even becomes more variable, V/Q heterogeneity increases at increased Qt. (omicsonline.org)
  • Six group E dogs were infused with endotoxin at a rate of 0.25 microgram/kg min, while six additional animals served as control (group C). Endotoxin induced increases in flow resistance from 0.056 to 0.096 mm Hg/ml/min/kg due to arterial vasoconstriction and increases in critical closure from 2.3 to 8.4 mm Hg due to a venous waterfall. (uliege.be)
  • As altitude increases, the available amount of oxygen to sustain mental and physical alertness decreases with the overall air pressure, though the relative percentage of oxygen in air, at about 21%, remains practically unchanged up to 21,000 metres (70,000 ft). (wikipedia.org)
  • occurs
  • Energy needed to perform short lasting, high intensity bursts of activity is derived from anaerobic metabolism within the cytosol of muscle cells, as opposed to aerobic respiration which utilizes oxygen, is sustainable, and occurs in the mitochondria. (wikipedia.org)
  • The RMS velocities of diatomic nitrogen and oxygen are very similar and thus no change occurs in the ratio of oxygen to nitrogen until stratospheric heights. (wikipedia.org)
  • inhalation
  • Bindslev L, Hedenstierna G, Santesson J, Gottlieb I and Carvallhas A.: Ventialtion-perfusion distribution during inhalation anaesthesia. (springer.com)
  • nitric oxide
  • A particularly important intermediate in the chemical industry, nitric oxide forms in mixtures of nitrogen and oxygen at high temperatures, as found in combustion systems such as internal-combustion piston engines, gas turbines, furnaces, and boilers. (wikipedia.org)
  • When exposed to oxygen, nitric oxide is converted into nitrogen dioxide. (wikipedia.org)
  • In water, nitric oxide reacts with oxygen and water to form HNO2 or nitrous acid. (wikipedia.org)
  • The nitric oxide reacts with the ozone to produce oxygen and nitrogen dioxide, accompanied with emission of light (chemiluminescence): ·NO + O3 → NO2 + O2 + hν which can be measured with a photodetector. (wikipedia.org)
  • cardiopulmonary
  • Cardiopulmonary resuscitation (CPR) is performed in order to restore oxygen delivery and prevent multiorgan system failure and death. (hindawi.com)