Scientifically embryologists define human life based on a set of three criteria:
it responds to stimuli
it has cellular reproduction
it is metabolizing
As long as at-least two of these criteria are present, human life is present. An unborn human meets all three pieces of criteria.
The scientific definition of human life is not a up for debate, it is a black and white scientific fact.
An unborn human cannot be compared to other elements of the mother such as dead skin or hair, as an unborn human is a distinct, living and whole human being with its own unique individual DNA - separate to that of its parents.