This is an old presentation re-posted recently. Ivor Cummins explaining how the body uses cholesterol and its mechanism. Well worth the listen and watch.

https://www.youtube.com/watch?v=WX61clbpxeE&t=1639s  #mce_temp_url#

Edit: This is an outstanding presentation that I had missed in the last 6 years of studying this stuff. He had this figured out 11 years ago.