Contour line factors in a weather system. An isobar (from or "baros", meaning 'weight') is a line of equal or constant pressure on a graph, plot, or map; an isopleth or contour line of pressure. More accurately, isobars are lines drawn on a map joining places of equal average atmospheric pressure reduced to sea level for a specified period of time. In meteorology, the barometric pressures shown are reduced to sea level, not the surface pressures at the map locations. The distribution of isobars is closely related to the magnitude and direction of the wind field, and can be used to predict
Mean arterial pressure Mean arterial pressure In medicine, the mean arterial pressure (MAP) is an average blood pressure in an individual during a single cardiac cycle. Total Peripheral Resistance (TPR) is represented mathematically by the formula:mean arterial pressure R = ΔP/Q R is TPR. ΔP is the change in pressure across the systemic circulation from its beginning to its end. Q is the flow through the vasculature (equal to cardiac output) In other words: Total Peripheral Resistance = (Mean Arterial Pressure - Mean Venous Pressure) / Cardiac Output Therefore, Mean arterial pressure can be determined from: where: While MAP can only be measured