Sarcoplasmic

Part of speech: adjective

Definitions

1. Of or pertaining to the cytoplasm that fills muscle fibers and surrounds the contractile proteins
2. Concerning the gel-like substance within muscle cells that contains proteins and organelles but excludes the myofibrils
3. Relating to the watery protoplasm of skeletal or cardiac muscle tissue that lies between and around the myofilaments

Etymology: Sarcoplasmic is a plain technical formation: it is simply "sarcoplasm" with the adjective suffix "-ic" attached. The noun it builds on combines two Greek elements. "Sarco-" comes from Greek "sarx," meaning flesh, and "-plasm" comes from Greek "plasma," meaning something formed or moulded. Together, "sarcoplasm" names the cytoplasm of a muscle cell, the substance that surrounds its fibres. The suffix "-ic" is inherited from Latin "-icus," which passed into English through Old French "-ique" and reached Middle English as "-ik" before the modern spelling settled. It is the same ending found in words such as "chronic" or "magnetic," and it turns a noun into an adjective meaning "relating to" or "characteristic of." So "sarcoplasmic" means relating to sarcoplasm. Because it was built from Greek parts in modern scientific writing, the word did not exist in ancient Greece. Its components are classical, but the compound itself is a later coinage made for describing cell biology.