Pronunciation: [tɹa͡ɪd͡ʒˈɛmɪnə͡l nˈɜːv] (IPA) 
The trigeminal nerve is a cranial nerve responsible for sensation in the face. It is spelled /traɪˈdʒɛmɪnəl nərv/, with the first syllable pronounced like "try", the second like "gem", and the third like "inal". The "g" sound in "gem" is soft, as in the word "gym". The "e" in "nerve" is silent. This nerve can cause intense pain when irritated, and disorders of the trigeminal nerve can be debilitating.
The trigeminal nerve, also known as the fifth cranial nerve or simply CN V, is one of the twelve pairs of cranial nerves that emanate from the brain. It is the largest of all the cranial nerves and plays a crucial role in sensory perception and motor function of the face.
The trigeminal nerve is responsible for transmitting sensations, such as touch, pain, and temperature, from the face, mouth, and nose to the brain. It consists of three main branches: the ophthalmic nerve (V1), the maxillary nerve (V2), and the mandibular nerve (V3). These branches innervate different areas of the face and are responsible for relaying specific sensory information.
Furthermore, the trigeminal nerve controls motor function in the muscles involved in chewing (mastication). It innervates the muscles responsible for jaw movement and certain muscles involved in swallowing.
Additionally, the trigeminal nerve is involved in important reflexes, such as the corneal reflex (blink reflex), which involves stimulation of the cornea to produce an automatic blink response.
Disorders or damage to the trigeminal nerve can result in various conditions, including trigeminal neuralgia, a severe facial pain disorder characterized by sudden and intense facial pain. Other conditions may include numbness, altered sensations, or muscle weakness in the face.
In summary, the trigeminal nerve is a major cranial nerve that provides both sensory and motor innervation to various areas of the face, and plays a vital role in facial sensation, movement, and reflex actions.
Nervus trigeminus.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.
The word "trigeminal" is derived from Latin, specifically from the words "tri" meaning "three" and "geminus" meaning "twin". The "trigeminal nerve" is so named because it is divided into three main branches, making it a nerve with three parts or divisions.
