Low-pressure area area of wind divergence aloft occurs ahead of embedded shortwave troughs, which are of smaller wavelength. Diverging winds aloft ahead of these troughs cause atmospheric lift within the troposphere below, which lowers surface pressures as upward motion partially counteracts the force of gravity. Thermal lows form due to localized heating caused by greater sunshine over deserts and other land masses. Since localized areas of warm air are less dense than their surroundings, this warmer air rises, which lowers atmospheric pressure near that portion of the Earth's surface. Large-scale thermal lows over continents help drive monsoon circulations. Low-pressure areas can also
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