The process by which people are eaten is called anthropophagy,which includes cannibalism, and self-cannibalism, as well as predation on humans by carnivores.
A scientific field (which is not current recognized) could be anthropophagology.
Similarly, self-cannibalism could be term autoanthropophagy.
anthorpology
Hydrology is the study of bodies of water
the study of eating disorders
Biology
Biology
Astronomy.
The study of the human lungs can be called respirology or pulmonology.
Paleoanthrology is the study of ancient human hominids.
Understanding the different systems of bodies
anthropolgy
Yes, this is called astronomy
astrology