1 Intracellular fluid (2/3 of body water). 2  Per Guyton, in a body containing 40 litres of fluid, about 25 litres is intracellular, which amounts to 62.5% (5/8), close enough to the 2/3 rule of thumb. 3  Jackson's texts states 70% of body fluid is intracellular. 4  Extracellular fluid (1/3 of body water).
However, if you provided support to your brother, depending on the level of support and your brotherâs gross income for 2010, you may be able to claim him as a dependent on your tax return (under the qualifying relative rules).
Support claimed under a multiple support agreement. If you are considered to have provided more than half of a qualifying relative's support under a multiple support agreement, you can include medical expenses you pay for that person.