Among the many factors that modulate tension (vessels, heart strength, blood volume ...), the kidney plays a vital role because it makes an enzyme called renin that helps increase blood pressure and it regulates the outflow of sodium and water, which contribute to the elevation or diminution of blood pressure in the arteries.
Xerophytes are plants that have adapted to arid climates. They have evolutionary developed adaptations to reduce the rate of transpiration so as to conserve water.
Among the adaptations include; thick cuticle, small, thick leaves, reducing the surface area relative to the volume of the leaf, etc.
Additionally, they use CAM pathway as an alternative photosynthetic pathway to minimize water loss.