a narrow opening produced by cleavage or separation of parts. 2. cleavage (def 1). 3. Anatomy. a natural division or groove in an organ, as in the brain. verb (used with object), fissured, fissuring. 4. to make fissures in; cleave; split.
A diet rich in potassium helps to counterbalance some of sodium's harmful effects on blood pressure. Foods that are good sources of potassium are listed in the Food Sources of Potassium table on the next page.
Sodium is an essential electrolyte that helps maintain the balance of water in and around your cells. Sodium is important for proper muscle and nerve function. It also helps to maintain stable blood pressure levels. Low blood sodium occurs when water and sodium are out of balance.