The lower (lumbar) spine allows your body to turn, twist, and bend. It also gives strength for standing, walking, and lifting. The lower back is involved in almost all movement. Pain in the lower back is very common.
Arteries are blood vessels that carry blood from your heart to the rest of your body. Arteritis is inflammation of your arteries. Blood vessel inflammation in general is called vasculitis.
A bursa is a small sac filled with fluid. You have many bursae (the plural of bursa). Bursae cushion your muscles, tendons, and ligaments around joints and keep them from rubbing against each other.
Bones are constantly breaking down and rebuilding, a process known as remodeling. In this process, old bone tissue is gradually replaced by new bone tissue.