Nervus

Nervus is the Latin word for nerve, and it appears in anatomical terminology as the basic noun for a peripheral nerve. In formal nomenclature, especially in older or purely Latin texts, many nerves are named with nervus, as in nervus olfactorius (I), nervus opticus (II), nervus trigeminus (V), nervus facialis (VII), nervus vagus (X), and nervus accessorius (XI). In everyday English-language anatomy, these structures are usually referred to by their English names, but the Latin form remains standard in scientific naming conventions.

A nerve is a bundle of axons enclosed by connective tissue and is part of the peripheral nervous system. It serves to transmit electrical impulses between the central nervous system and peripheral targets, providing sensory input, motor output, or a combination of both. Nerves are organized into fibers that are surrounded by endoneurium, grouped into fascicles by perineurium, and encased by an outer epineurium. Blood vessels, collectively called the vasa nervorum, traverse the nerve to supply it. The fibers may be myelinated or unmyelinated, and conduction speed depends on fiber type and diameter.

Nerves are classified as cranial nerves, which originate from the brain, or spinal nerves, which emerge from the spinal cord. Clinically, nerve injury or disease can cause neuropathies or radiculopathies, with symptoms such as sensory loss, weakness, or altered reflexes. The study of nerves and their disorders is foundational to neurology and neuroanatomy, and the Latin term nervus remains a core element of botanical and medical etymology in historical and academic contexts.