Roman physician galen advanced the study of body structure called Mythology
Astronomy
Satire
Anatomy

Galen's understanding of anatomy and medicine was principally influenced by the then-current theory of humorism (also known as the theory of the four humors: black bile, yellow bile, blood, and phlegm), as advanced by ancient Greek physicians such as Hippocrates.

depends on the age of the teen, many believe by the age of 16 a person should know the strong difference between right and wrong along with the difference between risky and immediate death. swimming with sharks might be dangerous but swimming with sharks while bloody meat is attached to you is just insane. even more if you have no idea what you're doing. however, no matter the age, as long as the person is skilled enough and has the mental and physical capacity to control their actions doing whatever sport they put their mind to is all that matters.