Both theories were put forth by members of the UW Pathology Department, Russell Ross and Earl Benditt, respectively. There are not many wasted words on these few pages. Take some time with this material. Also, try to learn the pathogenesis in relation to the risk factors for atherosclerosis. For example, cigarette smoke can injure endothelium, thus explaining why smokers are at risk.
Hypertension causes increased filtration of lipoprotein into the intima from the blood.
Not all the risk factors can be explained this way, but many can. Also, another risk factor for the development of atherosclerosis that has received a lot of press and has been championed by Thomas Grayston from the U of W is infection with the bacterial pathogen Chlamydia pneumoniae. A causal relationship between C. pneumoniae infection and atherosclerosis has not been proven, but considerable effort is being directed toward studies regarding this relationship. Page 524-528 Note that atherosclerosis is one of the more important causes of abdominal aortic aneurysms. It is not necessary at this time to know all the details of the different types of aneurysm and dissection.