Search results
Results from the WOW.Com Content Network
The V/Q ratio in the apex is roughly 3.3 and 0.63 in the base, which indicates that perfusion is greater than ventilation towards the base, and the ventilation rate is greater than perfusion towards the apex. Towards the base of the lungs, the fluid volume in the pleural cavity increases due to gravity, resulting in greater intrapleural pressure.
In respiratory physiology, the ventilation/perfusion ratio ( V/Q ratio) is a ratio used to assess the efficiency and adequacy of the ventilation-perfusion coupling and thus the matching of two variables: V – ventilation – the air that reaches the alveoli. Q – perfusion – the blood that reaches the alveoli via the capillaries.
Local venous pressure falls to -5 at the apexes and rises to +15 mmHg at the bases, again for the erect lung. Pulmonary blood pressure is typically in the range 25–10 mmHg with a mean pressure of 15 mmHg. Regional arterial blood pressure is typically in the range 5 mmHg near the apex of the lung to 25 mmHg at the base.
Transpulmonary pressure is the difference between the alveolar pressure and the intrapleural pressure in the pleural cavity. During human ventilation, air flows because of pressure gradients. P tp = P alv – P ip. Where P tp is transpulmonary pressure, P alv is alveolar pressure, and P ip is intrapleural pressure.
8452-5. Pulsus paradoxus, also paradoxic pulse or paradoxical pulse, is an abnormally large decrease in stroke volume, systolic blood pressure (a drop more than 10 mmHg) and pulse wave amplitude during inspiration. Pulsus paradoxus is not related to pulse rate or heart rate, and it is not a paradoxical rise in systolic pressure.
Cardiac systole is the contraction of the cardiac muscle in response to an electrochemical stimulus to the heart's cells ( cardiomyocytes ). Cardiac output is the volume of blood pumped by the ventricles in one minute. The ejection fraction is the volume of blood pumped divided by the total volume of blood in the left ventricle.
A forceful apex beat indicates left ventricular pressure overload, while a right ventricular heave suggests right ventricular pressure overload. Other signs provide evidence for specific causes of pressure overload. Hypertension is diagnosed by sphygmomanometry. A narrow pulse pressure is a sign of aortic stenosis.
CSF/S alb = 7.5. CSF/S glu = 0.6. The factors that determine the values for alveolar pO 2 and pCO 2 are: The pressure of outside air. The partial pressures of inspired oxygen and carbon dioxide. The rates of total body oxygen consumption and carbon dioxide production. The rates of alveolar ventilation and perfusion.
Compliance (physiology) Compliance is the ability of a hollow organ (vessel) to distend and increase volume with increasing transmural pressure or the tendency of a hollow organ to resist recoil toward its original dimensions on application of a distending or compressing force. It is the reciprocal of "elastance", hence elastance is a measure ...
The shockwave from the Chelyabinsk meteor that rocketed across the Russian morning sky on 15 February 2013. In physics, a shock wave (also spelled shockwave ), or shock, is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through ...