Low-pressure area Low-pressure area A low-pressure area, low, depression or cyclone is a region on the topographic map where the atmospheric pressure is lower than that of surrounding locations. Low-pressure systems form under areas of wind divergence that occur in the upper levels of the troposphere. The formation process of a low-pressure area is known as cyclogenesis. Within the field of meteorology, atmospheric divergence aloft occurs in two areas. The first area is on the east side of upper troughs, which form half of a Rossby wave within the Westerlies (a trough with large wavelength that extends through the troposphere). A second
Low pressure receptors both an increase in heart rate and a decrease in vasopressin (ADH) secretion from posterior pituitary, and renin and aldosterone. The decrease in vasopressin secretion results in an increase in the volume of urine excreted, serving to lower blood pressure. In addition, stretching of atrial receptors increases secretion of atrial natriuretic peptide (ANP), which promotes increased water and sodium excretion through the urine. In the right atrium, the stretch receptors occur at the junction of the venae cavae. In the left atrium, the junction is at the pulmonary veins. Low pressure receptors Low pressure receptors are baroreceptors located in large