Answer: Dermatology
Like you said, derma means skin and having the terminology -logy <span>indicates </span><span>names of scientific fields of study. Basically, dermatology is the branch of medicine that studies skin but also studies </span>scalp, hair, and nails (because they are all associated).
<span />
Answer:
As seen in the question above, "constraint" is a word that indicates a limitation or condition. In this case, we can say that the "restriction" is an imposition to a limit under a given situation, and it can also mean an imposition of the free execution of an activity, skill and even limitation and a conditioning factor to a certain freedom.