The first number (120) is the systolic blood pressure. This is the pressure reading once the heart pumps, send a large volume of blood coursing through the artery and causing there to be more pressure in the artery at that moment.
The second number (80) is the diastolic pressure. This is the pressure reading after the heart has pumped and is refilling with blood. The diastolic reading is lower than the systolic reading because there is a lower volume of blood flowing through the artery after that initial pump from the heart, and therefore there is less pressure in the artery.
The density of water increases as the salinity increases. The density of seawater (salinity greater than 24.7) increases as temperature decreases at all temperatures above the freezing point. The density of seawater is increased by increasing pressure.
The water molecules in the cell will want to move out of the cell into the pond in attempt to lower the salt concentration which will cause the cells to shrivel up with the loss of water. This is also called becoming hypertonic.