What Is the Nervus Trigeminus?

The trigeminal nerve is the fifth pair of brain nerves among twelve pairs of brain nerves, and is one of the mixed brain nerves. The trigeminal nerve consists of two fibrous components.

The trigeminal nerve is the fifth pair of brain nerves among twelve pairs of brain nerves, and is one of the mixed brain nerves. The trigeminal nerve consists of two fibrous components.

Chinese name

Trigeminal nerve

Foreign name

n.trigeminus

nickname

Mixed nerve

Main composition

Ophthalmic nerve, maxillary nerve, mandibular nerve

Common illnesses

Trigeminal neuralgia

Common causes

5th pair of brain nerve damage

Common disease groups

Female population, elderly population

Multiple groups

Middle-aged and elderly, female

Visiting department

Neurology

Trigeminal nerve 1. Fiber composition:

One is the general somatosensory fiber. The neuron cell body is located in the trigeminal ganglion of the cranial fossa temporal bone rock. The central process of the trigeminal ganglion forms the sensory root of the trigeminal nerve. It enters the brain at the junction of the brainstem pons and the base of the pons. In the trigeminal spinal nucleus.

The other type of fiber is a special visceral motor fiber, which originates from the trigeminal motor nucleus in the special visceral motor nucleus. The special visceral motor fiber component from the trigeminal motor nucleus forms the trigeminal motor root, which exits from the junction of the pontine arm and the base The brain and fibrous components are added to the third branch of the trigeminal nerve. The mandibular nerve innervates the muscles such as the masticatory muscles.

Trigeminal nerve 2. Classification:

The peripheral processes of the trigeminal ganglion constitute the three major branches of the trigeminal nerve, the ophthalmic nerve, the maxillary nerve, and the mandibular nerve.

(1) Ocular nerve:

The eye nerve is a sensory nerve, and the fiber component is a general somatic sensory fiber. After it is emitted from the trigeminal ganglion, it penetrates the supraorbital fissure into the orbit, and emits branches such as the frontal nerve, lacrimal nerve, and nasolacrimal nerve. General somatosensory information on facial skin, conjunctiva, eyeballs, and some paranasal sinus mucosa.

1. The frontal nerve is thicker and is located above the levator levator muscle, divided into 2 to 3 branches, of which the supraorbital nerve is larger, and the branches are distributed on the frontal frontal skin through the supraorbital notch.

2. The lacrimal gland is small and runs along the outer wall of the orbit and the upper edge of the external rectus muscle until the lacrimal gland is distributed on the skin of the lacrimal gland and upper eyelid.

3. The naso-laryngeal nerve is on the deep side of the superior rectus muscle, over the optic nerve to the medial orbital wall. This nerve is divided into many branches, which are distributed in the eyeball, sphenoid sinus, ethmoid sinus, lower eyelid, lacrimal sac, nasal mucosa, and dorsal nasal skin.

(B) the maxillary nerve:

The maxillary nerve is a sensory nerve, containing general somatosensory fibers. It passes through the outer wall of the cavernous sinus and exits the skull through a circular hole. It emits suborbital nerves, alveolar nerves, phrenic nerves, and pterygopalatine nerves. They are distributed in the maxillary teeth and gums. Nasal mucosa.

1. The infraorbital nerve enters the orbit through the infraorbital fissure, and then spreads into several branches through the infraorbital sulcus, infraorbital canal, and infraorbital foramen, and is distributed on the skin of the lower eyelid, the lateral part of the nose, the upper lip, and the cheek. When performing maxillary surgery clinically, anesthesia is often performed at the suborbital foramen. The infraorbital nerve issues the anterior alveolar branch in the infraorbital canal to the teeth and gums of the anterior maxilla. When the infraorbital nerve is damaged, sensory disturbances in its innervation area occur.

2. The upper alveolar nerve is divided into three groups: The posterior branch of the alveolar nerve, 2 to 3 branches from the pterygopalatine fossa of the maxillary nerve, penetrate the back of the maxilla and enter the bone, and are distributed over the maxillary sinus, maxillary molars, gums and Buccal mucosa; the middle branch of the upper alveolar, which originates from the infraorbital sulcus, and is distributed over the maxillary premolars and gums; the anterior branch of the upper alveolar, which is issued from the infraorbital canal, 2 to 3, and is distributed on the maxillary incisors and canines And gums.

3. The phrenic nerve is relatively small, separated at the pterygopalatine fossa, and inferior to the orbital nerve through the suborbital fissure into the orbital, penetrating through the outer wall of the orbital and distributed on the palatal skin. If this nerve is damaged, the distribution area feels impaired.

(C) the mandibular nerve:

The mandibular nerve is a mixed nerve. It consists of special visceral motor fibers and general somatosensory fibers. It penetrates the oval hole and exits the skull, and emits the temporal nerve, buccal nerve, lingual nerve, alveolar nerve, and masticatory nerve. Dominates the masticatory muscles, etc .; the sensory fibers manage the general sensation of the temporal area, the skin below the cleft palate, the 2/3 mucosa of the tongue, and the mandibular teeth and gums.

Trigeminal nerve trigeminal nerve injury:

When the trigeminal nerve is damaged above the meniscus: general sensation loss of the skin of the head, face, tongue, mouth, and nasal mucosa of the affected side may occur; corneal reflex disappears; the chewing muscles of the affected side are paralyzed, and the jaw is biased toward the affected side when the mouth is opened.

When the trigeminal nerve is damaged below the meniscus: each single branch can appear, when the eye nerve is damaged, skin sensations above the affected eyelid fissure and corneal reflex disappear; when the maxillary nerve is injured, the affected lower eyelid and upper lip skin , Maxillary teeth, gums, and epiphyseal dysfunction; when the mandibular nerve is damaged, it can cause general sensory disorders of the affected mandibular teeth, gums, anterior 2/3 of the tongue, and mandibular skin, and dyskinesia of the affected chewing muscles.