Trigeminal Nerve V1, V2, V3
Trigeminal nerve: V1 and V2
Trigeminal nerve provides large root of sensory nerve to the front of the face and head, and a small root of motor nerves to innervate muscles of mastication, mylohyoid, and digastric (anterior belly)
Sensory root
Fibres Convey common sensation (touch, temperature, pressure, pain) to the skin of the front of the face and the scalp as far back as the vertex of the head
Sensory innervation to the oral cavity, dental and paradental structures
For this reason, branches of these nerves are anaesthetized for comfortable dental procedures
Course The 3 divisions of the sensory root unite as the Trigeminal ganglion, housing the cell bodies of unipolar somatic sensory neurons in the middle cranial fossa.
Their proximal axon continues and enter the brainstem at the mid-pons, where they synapse at the nucleus of V Divisions
OPTHALMIC DIVISION
CN V1
Purely sensory Anterior portion of the scalp and the forehead, the upper eyelid, the front of the nose as far down as its tip
MAXILLARY DIVISION
CN V2
Purely sensory Skin at the side of the nose, the lower eyelid, and the upper part of the cheek and upper lip
MANDIBULAR DIVISION
CN V3
Sensory & Motor Chin and lower lip, the skin in front of the ear, and the skin of the side of the head up to the area supplied by the ophthalmic division
Angle of mandible & back or head and much of neck is NOT supplied by trigeminal nerve but the cervical nerves C2 AND c3
Nuclei
(cluster of neurons in CNS) Afferent sensory neurons synapse in three brainstem nuclei, containing sensory nuclei of 2nd order neurons.
Nuclei
Mesencephalic nucleus
**Only peripheral sensory cells in the body whose cell bodies ARE located in CNS, NOT the trigeminal ganglion
Proprioceptive fibres involved in reflex responses
Senses in the palatine, maxilla, PDL, muscles of mastication
Spatial awareness
Principal (chief) sensory nucleus Touch
Spinal nucleus
(divides into 3 sections) Pain and temperature
Trigeminal nerve provides large root of sensory nerve to the front of the face and head, and a small root of motor nerves to innervate muscles of mastication, mylohyoid, and digastric (anterior belly)
Sensory root
Fibres Convey common sensation (touch, temperature, pressure, pain) to the skin of the front of the face and the scalp as far back as the vertex of the head
Sensory innervation to the oral cavity, dental and paradental structures
For this reason, branches of these nerves are anaesthetized for comfortable dental procedures
Course The 3 divisions of the sensory root unite as the Trigeminal ganglion, housing the cell bodies of unipolar somatic sensory neurons in the middle cranial fossa.
Their proximal axon continues and enter the brainstem at the mid-pons, where they synapse at the nucleus of V Divisions
OPTHALMIC DIVISION
CN V1
Purely sensory Anterior portion of the scalp and the forehead, the upper eyelid, the front of the nose as far down as its tip
MAXILLARY DIVISION
CN V2
Purely sensory Skin at the side of the nose, the lower eyelid, and the upper part of the cheek and upper lip
MANDIBULAR DIVISION
CN V3
Sensory & Motor Chin and lower lip, the skin in front of the ear, and the skin of the side of the head up to the area supplied by the ophthalmic division
Angle of mandible & back or head and much of neck is NOT supplied by trigeminal nerve but the cervical nerves C2 AND c3
Nuclei
(cluster of neurons in CNS) Afferent sensory neurons synapse in three brainstem nuclei, containing sensory nuclei of 2nd order neurons.
Nuclei
Mesencephalic nucleus
**Only peripheral sensory cells in the body whose cell bodies ARE located in CNS, NOT the trigeminal ganglion
Proprioceptive fibres involved in reflex responses
Senses in the palatine, maxilla, PDL, muscles of mastication
Spatial awareness
Principal (chief) sensory nucleus Touch
Spinal nucleus
(divides into 3 sections) Pain and temperature