The inward-pulling force of particles in the vascular space by proteins is called the

capillary oncotic pressure.

In the vascular system, there is the hydrostatic pressure that caused by the heart pumping the blood and oncotic pressure that caused mostly by protein. This pressure keeps the water inside the blood vessel and a change can cause some disease.
Low protein in the blood can cause edema which was the water inside blood vessel come out to interstitial tissue because the oncotic pressure is dropped.

An  atom  (ours, not carroll's) consists of a positively charged  nucleus, surrounded by one or more negatively charged particles called  electrons. the positive charges equal the negative charges, so the atom has no overall charge; it is electrically neutral. most of an atom's mass is in its nucleus; the mass of an electron is only 1/1836 the mass of the lightest nucleus, that of hydrogen. although the nucleus is heavy, it is quite small compared with the overall size of an atom. the radius of a typical atom is around 0.1 to 0.25 nanometres (nm), whereas the radius of a nucleus is about 10-6  nm.  *  if an atom were enlarged to the size of the earth, its nucleus would be only 200 feet in diameter and could easily rest inside a small football stadium.read more on -