A nervus is a group of nerve fibers bundled in a cluster. The formal Latin names for many nerves include the term “nervus,” as seen in “nervus trigeminus,” “nervus vagus,” and so forth. It can be useful to be aware that this word translates as “nerve bundle,” as this can provide some clarity in discussions about anatomy and medical conditions. If a situation involves a “nervus,” it means that a nerve must be involved.
Bundles of nerves begin to be laid very early in fetal development and the nervous system continues developing after birth. The peripheral nervous system includes all of the nerves that branch off from the brain and spinal cord to handle everything from moving the facial muscles to the automatic contractions in the intestinal tract that facilitate digestion. Individual nerves are named either for their function, structure, or destination, like the optic nerve, trigeminal nerve, and facial nerves.
Inside an individual grouping of nerve fibers, both motor and sensory neurons can be present. Motor neurons send signals to move muscles and other tissues in the body. Sensory neurons collect sensory information and relay it along the nervus to the spinal cord and the brain. This information is interpreted to provide information about the body's surrounding environment. Motor and sensory neurons can work together, as when one set of neurons sends a message that the body is in contact with something dangerously hot and another set jerks the body away to prevent or limit burning.
The nervous system of the human body has been extensively mapped. Anatomical drawings are available to demonstrate the pathways traced by nerves as they move through the body and to highlight the different kinds of nerves present in the body. This information is studied in detail by physicians during their medical education so they can provide appropriate treatment to people with neurological problems and avoid hitting nerves during surgical procedures, manipulative therapy, injections, and other types of medical procedures.
A material known as meylin insulates neurons so they can conduct signals accurately and effectively. Problems with nerve conduction can involve breakdown of myelin that interferes with signaling, damage along the length of a nervus that interrupts signals, and problems with the brain or spinal cord that prevent signals from being sent or received. People with neurological conditions that attack their nerves can experience a variety of symptoms related to poor nerve signaling, from difficulty walking to numbness in the extremities.