See a picture of the spine. Upper and middle back pain is not as common as low back pain or neck pain, because the bones in this area of the back don't flex or move as much as the bones in your lower back or neck.
Fats are a class of lipids containing two kinds of monomers, fatty acids and glycerol. Glycerol is a three carbon biomolecule containing three hydroxyl groups, one bonded to each carbon atom. Dehydration synthesis creates an ester linkage between the carboxyl group of fatty acids and a hydroxyl group in glycerol.
In biology, lipids comprise a group of naturally occurring molecules that include fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E, and K), monoglycerides, diglycerides, triglycerides, phospholipids, and others.