so what we're looking at here is long bone anatomy this is what i use instead of the frozen bone so looking at this picture here you see these brackets on the sides here those brackets are separating the bone into the middle portion right here which is called the diaphysis so the middle portion of a long bone is called the diaphysis the ends of a long bone so where this is bracketed here and bracketed there are called the epiphyses epiphysis for single so here's one epiphysis here's the other epiphysis now around all bone is um some connective tissue some tough fibrous connective tissue and on this bone they have a cut so we can see that and that right there is trying to show so that is showing the periosteum so that's what this line is going to is the periosteum right there all right now within the long bone is a cavity and we see this little cavity right here and that cavity is called the medullary cavity and what is stored in that cavity is this stuff right here this yellow stuff and that right there is called the yellow bone marrow so that contains lipids so fats all right now we look on the sides of the uh diaphysis here we're seeing that the bone here is pretty solid and that area right there is called compact bone that's the type of bone that that is that's what that line is going to so that's compact bone now moving up here into an epiphysis we see that the bone in this area here is very porous and this bone type here is called spongy bone so that is spongy bone right there now those cavities are filled in with another type of bone marrow and that's called red bone marrow red bone marrow makes our blood cells and that fills those internal cavities so it's essentially how i ask the question what is it it is spongy bone what's found within it is red bone marrow next here is this structure that we see here this is articular cartilage so it's a bit of hyaline cartilage around the end of the bone and it protects the bone so that is articular cartilage so that's what that line is going to and lastly you're seeing these areas where the bone is a little gets a little more dense in this area and those are the remnants of our growth plates and these are called the episeal plates okay so those are the episteal plates