Are there any resources for learning the "anatomy" and inner workings or features of general things in order to draw them better?

Learning anatomy of the human body has helped me so much not just in accurately drawing muscle forms but to simply understand how to draw it better all around since I understand it at the locomotion level, so I'm looking to replicate that with other topics, but I don't really know where to start and I don't have any personal projects to do research for.

Resources can be specifically for artists like pic related or something general like documentaries or encyclopedias.