Definition

Noun: * Accessory Nerve: The eleventh cranial nerve (CN XI). It is a motor nerve that arises from two distinct sets of roots—one in the brainstem (cranial roots) and one in the upper spinal cord (spinal roots)—which unite to form the single nerve. It primarily controls the sternocleidomastoid and trapezius muscles, which are involved in movements of the head, neck, and shoulders.

Usage Examples

• Noun:
  • Damage to the accessory nerve can result in weakness when turning the head or shrugging the shoulders.
  • The surgeon carefully avoided the accessory nerve during the neck dissection.
  • The accessory nerve is unique among the cranial nerves due to its spinal component.

Advanced Usage

• "Spinal accessory nerve": A common alternative name for the accessory nerve, emphasizing its spinal root origins.
  • The spinal accessory nerve is often assessed during a neurological examination by testing shoulder shrug strength.

Variants and Related Words

• Cranial Nerve XI: The formal numerical designation for the accessory nerve within the set of twelve cranial nerves.
• Sternocleidomastoid Muscle: A major neck muscle innervated by the accessory nerve, responsible for rotating and flexing the head.
• Trapezius Muscle: A large back and shoulder muscle innervated by the accessory nerve, responsible for moving the scapula.

Synonyms

• Eleventh Cranial Nerve: A direct synonym based on its numerical order.
• Nervus Accessorius: The Latin anatomical term.

Related Phrases

• Accessory nerve palsy/paralysis: A condition characterized by impaired function of the nerve.
  • The patient was diagnosed with accessory nerve palsy following the procedure.
• Accessory nerve injury: Damage to the nerve, often iatrogenic (caused by medical treatment).
  • Hoarseness and shoulder drop can be signs of an accessory nerve injury.

Noun

1. arises from two sets of roots (cranial and spinal) that unite to form the nerve