How are phospholipids arranged in a plasma membrane and what role do they play in maintaining the structure and function of the membrane?

Phospholipids in a plasma membrane are arranged in a bilayer, with the hydrophilic heads facing outward and the hydrophobic tails facing inward. This arrangement helps maintain the structure of the membrane and allows it to be selectively permeable, regulating the passage of substances in and out of the cell. The phospholipids also play a crucial role in cell signaling and maintaining the integrity of the membrane.