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.
Lipids. Fats, oils, waxes, and sterols are collectively known as lipids. Like the carbohydrates, the true fats contain only carbon, hydrogen, and oxygen. The molecules of such a lipid are made up of a glycerol molecule with three fatty acid molecules attached to it. This kind of lipid is also called a triglyceride. An important class of lipids is composed of the phospholipids that make up cell membranes. The class of compounds called steroids are also lipids, and cholesterol is one of the steroids.