L6: Trigeminal Nerve Flashcards
Sensory Innervations of the Trigeminal Nerve?
○ Facial Skin/Scalp (to top of head)
○ Tragus of the ear
○ Anterior wall of external auditoary canal
○ Cornea
○ Sensation from Mouth including:
- Anterior 2/3 of Tongue (Not Taste)
- Teeth
- Nasal/paranasal sinuses
- Meninges
Motor Innervations of the Trigeminal Nerve?
MANDIBULAR BRANCH => derivatives of 1st pharyngeal arch:
○ Muscles of Mastication:
- Temporalis
- Masseter
- Medial/Lateral Pterygoid muscles
○ Anterior Belly of Digastric
○ Mylohyoid
○ Tensor Veli Platini
○ Tensor Tympani
Trigeminal Nerve relationship with Cranial Parasymptahtic Outlfow
Postganglionic parasympathetic fibers are found in branches of the trigeminal nerve, but these join the nerve later, and the trigeminal is not part of the parasympathetic cranial outflow
Largest cranial nerve (by diameter)?
Trigeminal Nerve
Nuceli and Branches of the trigeminal Nerve
Trigeminal Nerve CENTRAL to PERIPHERAL Transition?
MS affects _______________ part of the Trigeminal Nerve
MS affects Proximal (central) part of Trigeminal Nerve (OLIGODENDROCYTES impacted not Swan Cells)
Trigeminal Ganglion lies LATERAL to ____________. It fits into a depression in __________ known as ____________ (CSF Filled Dural Pouch). Afterwards, the ganglion nerve divides into ________ main branches.
Trigeminal Ganglion lies LATERAL to Cavernous Sinus. It fits into a depression in Temporal Bone known as Merkel’s Cave (CSF Filled Dural Pouch). Afterwards, the ganglion nerve divides into THREE main branches.
Branches of the Trigeminal Nerve
Trigeminal Nerve CN V1 (Ophthalmic Division)
What does the Ophthalmic Division (CN V1) of the Trigeminal Nerve Innervate? (5)
- Forehead/Scalp
- Nose
- Frontal and Ethmoid Sinuses
- Upper Eye Lid
- Cornea
What can be learned from the Cornel Reflex Test?
Touch Cornea:
- No reaction on either side: Lesion on sensory side (Trigeminal Nerve)
- Reaction on 1 side not the other: Lesion on Motor Side (Facial Nerve)
Trigeminal Nerve CN V2 (Maxillary Division)
What does the Maxillary Division (CN V2) of the Trigeminal Nerve Innervate? (6) Parasympathetic Carry?
Innervates:
- Lower Eye Lid
- Cheeks
- Maxillary Sinuses
- Nasal Cavity
- Upper Teeth and Lip
- Superior Palate
Parasympathetic Fibers to:
- Lacrimal Glands
- Nasal Glands
Trigeminal Nerve CN V3 (Mandibular Division)
What does the Mandibular Division (CN V2) of the Trigeminal Nerve Innervate? (6)
Parasympathetic Carry?
Innervates:
- Anterior 2/3 of Tongue (not Taste)
- Lower Lip and Chin
- Lower Teeth
- Floor of oral cavity
Motor Supply:
- Muscles of Mastication (Temporalis, Masseter, Medial/Lateral Pterygoid)
- Anterior Belly of Digastric
- Mylohyoid
- Tensor Veli Platini
- Tensor Tympani
Parasympathetic Fibers to:
- Submandibular Glands
- Sublingual Glands
- Parotid Glands
Only branch of the Trigeminal nerve to carry MOTOR Fibers?
Mandibular Branch
Which sensory nucleus of the Trigeminal Nerve receives discriminative, fine touch, and conscious proprioception?
Primary Sensory Nucleus
Which sensory nucleus of the Trigeminal Nerve receives pain/temperature sensations?
Spinal Nucleus
Which sensory nucleus of the Trigeminal Nerve contains sensory neuron cell bodies associated with Proprioception and plays a role in the JAW JERK REFLEX?
Mesencephalic Nucleus
Information carried by ____________ Trigeminal (Ipsilateral) arises from the oral cavity. Rest of face is BILATERAL
What is Trigeminal Neuralgia?
Causes?
Treatment?
Trigeminal Neuralgia is a chronic pain condition characterized by sharp, usually unilateral, in one or more trigeminal territories
Cause is not always clear, but mostly involves mechanical compression of the nerve by vascular supply: Nociceptive (pain) neurons become damaged and are firing inappropriately. Pulsatile action of the artery => structural changes in nerve (loss of Myelin) => changes in ion channels making => aberrant firing => hyperactivity in sensory nucleus. Aso commonly associated with MS
Treated pharmacologically (anticonvulsants) or surgically (decompression, rhizotomy or adding in a Teflon pass that forms a barrier preventing compression of the nerve
