Adipose tissue while you can find it in all layers (I can go into the entire physiology if you want), it is more concentrated naturally and also is more correct by your class standards in the hypodermis. The hypodermis is the lower layer of the skin, and is used mainly to store adipose tissue (fat) as a way of conserving heat, and as a way of extra energy via Anaerobic processes, should it be needed.
