How are phospholipids oriented in the plasma membrane?

Phospholipids are oriented as a bilayer.

A phospholipid consists of two fatty acids, a glycerol molecule, a phosphate group, and an alcohol. The phospholipid molecule is amphipathic, that is, it has a section that is hydrophilic and another that is hydrophobic. In this case, the tails, or the fatty acids, are hydrophobic. In the presence of water, phospholipids aggregate together tail to tail, with the hydrophilic heads pointing outside the membrane.