The body has systems to modify or check blood pressure and the blood flow. Special sensors present in the lining of the heart and the arteries may sense the BP. Baroreceptors, the title of sensors. Baroreceptors feel BP and then convey signals to the kidneys, the arterioles, the heart and the veins that cause them to bring in modifications which lower or increase blood pressure. Adjustment of blood pressure is done in numerous ways.:

Raised heart speed can cause the more rapid shrinking of heart & ejects more blood. Such two responses raise the flow of blood into the arteries & elevate BP.

The veins can expand and narrow. When veins enlarge, more blood may be stored in the veins and less amount of blood comes back to the heart for pumping into the arteries. Therefore, the heart pumps less blood, and BP is lower. On the other hand, When and if veins contract, less amount of blood is collected in the veins, most of the amount of blood comes back to The heart for pumping in the arteries, and, thus, heart give out more blood & BP is higher.

The arterioles can expand and narrow. When and if arterioles expand blood pressure lowers because of less resistance to the blood flow and when arterioles narrow BP inflates due to increased resistance to the flow of blood.

Decreasing or increasing urine amount could also represent the modifications in blood pressure. The urine is generally amount of water that is eliminated of the blood thus when the kidney makes more urine, volume of blood which fills the arteries and veins decreases, and this lessens blood pressure.