Answer to Question 1
LDLs deposited along an injured artery's lining become oxidized; immune cells attracted to the site engulf the oxidized LDLs and transform into foam cells, which stick to the artery wall; foam cells accumulate, and with the arrival of platelets and various other circulating substances, thick deposits of plaque form. As the plaque deposit becomes larger, the artery becomes stiffened and narrowed internally, reducing blood flow through the vessel.
Answer to Question 2
Muscles use carbohydrates for energy during exercise of any intensity, but the amount used varies with intensity. As the intensity of exercise increases, so does the use of glucose and glycogen for energy. At very high exercise intensities, most of the body's energy needs is supplied by carbohydrates in the form of muscle glycogen. At moderate exercise intensities, carbohydrates provide about one-half to two-thirds of the energy needed by working muscles. (The rest is provided by fat.) At low to moderate intensity, fat is the body's primary energy source, but glucose in the bloodstream still provides some energy.
Model of the Reading Process
Atherosclerosis in the coronary arteries.
Structures of the ionized forms of some representative fatty acids (part 2)
Non-Hormonal Forms of Birth Control
Facet of superior articular process
How a seed forms