Final answer:
Sphingolipids with substituent phosphorylcholine are called sphingomyelins. Sphingomyelins are a subclass of sphingolipids and considered phospholipids. They play important roles in the myelin sheath and are associated with multiple sclerosis.
Step-by-step explanation:
If a sphingolipid has substituent phosphorylcholine, it is called sphingomyelin. Sphingomyelins are a subclass of sphingolipids that contain a fatty acid, a phosphoric acid, sphingosine, and choline. They are considered phospholipids due to the presence of phosphoric acid. Sphingomyelins play important roles in the myelin sheath surrounding nerve cells and are associated with diseases such as multiple sclerosis.