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).
When youâre claiming a dependent who is a child, there are further requirements: 1  The child has to have lived with you for at least half of the year. 2  The child has to be related to you. 3  That means your son, daughter, stepchild, foster child, brother, sister, stepbrother, stepsister, or a descendant of any of those.or a parent or other relative, there are different additional requirements: 1  The person cannot have a gross yearly income over $3,950. 2  The person canât be a qualifying child dependent of you or another person. 3  The person must be either related to you or must have lived with you all year as a member of your household.