I think burgess shells would be the answer
If you want to know how it looks outside of your body then that's when your fingers are wrinkled like if you soak your hands in water or take a long shower or bath that could be when water is entering your cells.
Hope this helps!
Answer:
A. Integumentary system
Explanation:
The integumentary system consists of the skin,hair and nail. This system consists of the largest organ in the body. The skin helps in protection against pathogens by shielding the internal body system from external objects.
The skin also helps in Vitamin D production through sunlight.
It also helps to prevent dehydration through regulation of water loss.