Blood clots will do this. Cutting off blood flow while also increasing blood pressure. Also, if the viscosity (thickness of the blood) is thick which will slow down the flow and cause the body to use more effort to pump blood.
Sun provides energy to plants, which use it to make food from soil nutrients, which is eaten by animal, which is eaten by another animal, that produces waste and die, that decomposes and adds nutrients to the soil, which plants use with sunlight to make food from soil
since the roots hairs grow in soil particles, they get water from the soil, thereby the cell wall and cell membrane absorbs the water through osmosis before transferring it to other parts of the roots