Drawing of a cross section of the breast of a human female.
<a href="//commons.wikimedia.org/wiki/User:YolanC" title="User:YolanC">User:YolanC</a>
Taken from <a rel="nofollow" class="external autonumber" href="https://training.seer.cancer.gov/ss_module01_breast/unit02_sec01_anatomy.html">[1]</a>