When someone sheds tears, they are expelled from cells through a mechanism known as endocytosis.
Regardless of the external conditions of the cell
Isotopes of a given element share the same characteristics, differing only in the neutron count within the nucleus.
The atomic number remains unchanged, whereas the mass number varies.
In this particular instance, protium, deuterium, and tritium represent isotopes of hydrogen.
Protium is 1H, or Hydrogen-1, which has no neutrons.
Deuterium is 2H, or Hydrogen-2, containing one neutron.
Tritium is 3H, or Hydrogen-3, consisting of two neutrons.
The digestive activity is regulated by mechanical and chemical receptors found in the walls of the tract organs.