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What is the largest terminal branch of CNV1?
Which nerve provides sensory innervation to the cornea?
What innervation does the lacrimal nerve provide?
What type of fibers does the lacrimal nerve receive from the zygomatic nerve of CNV2?
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Which nerve is absent in approximately 30% of people?
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What does the nasociliary nerve innervate?
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Which nerve contains sympathetic fibers to the dilator pupillae muscle?
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Which branch of the frontal nerve innervates the forehead?
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What is the primary function of the trigeminal nerve's motor fibers?
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Which branch of the trigeminal nerve contains motor fibers?
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Where is the trigeminal ganglion located?
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What is the role of the supratrigeminal nucleus?
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Which structure does the ophthalmic nerve NOT provide direct branches to?
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Which of the following is a terminal branch of the trigeminal nerve?
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Which cranial nerve is the largest and mixed in terms of sensory and motor function?
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What anatomical feature distinguishes the motor root of the trigeminal nerve from its sensory root?
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Which nerve is responsible for controlling the sphincter pupillae and effects pupil constriction?
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Where do sympathetic fibers that control the dilator pupillae originate from?
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Which branch of the ophthalmic nerve provides sensory innervation to the cornea?
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Which statement about the autonomic functions of the ophthalmic nerve is correct?
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What is the primary function of the maxillary nerve (CN V2)?
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Which of the following structures is NOT innervated by the maxillary nerve?
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Which nerve branches from the maxillary nerve and innervates the upper lip?
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What is the function of short ciliary nerves?
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What role does the maxillary nerve play when traveling with post ganglionic fibers from the pterygopalatine ganglion?
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Which of the following correctly describes the course of the inferior alveolar nerve?
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What types of fibers does the lingual nerve carry?
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Which nerve provides general sensory innervation to the buccal membranes?
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Which statement is true regarding the auriculotemporal nerve?
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The inferior alveolar nerve exits the mandibular canal through which opening?
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What is the primary function of the sensory fibers from the mandibular branch of CN V?
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The chorda tympani autonomic fibers associated with the lingual nerve eventually innervate which glands?
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What disorder is characterized by facial nerve paralysis without a definitive cause?
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Which section of the facial nerve is affected in extracranial lesions?
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What symptom is associated with damage to the chorda tympani?
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The most common cause of an intracranial lesion of the facial nerve is related to what?
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Which nerve is responsible for hypersensitivity to sound in the context of facial nerve damage?
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Which anatomical structure is NOT associated with the parasympathetic nervous system in the head and neck?
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The parasympathetic nervous system is primarily associated with which type of response?
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What is the primary function of the greater petrosal nerve?
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Study Notes
Trigeminal Nerve
- Fifth cranial nerve, mixed nerve (sensory and motor)
- Largest cranial nerve
- Sensory: 3 branches innervate face, mucous membranes, and sinuses
- Motor: Mandibular branch innervates mastication muscles, anterior digastric, tensor veli palatini, and tensor tympani
- Parasympathetic Supply: Post-ganglionic neurons travel with trigeminal nerve branches
Trigeminal Nerve Anatomical Course
- Originates from three sensory nuclei (Mesencephalic, Principal sensory, Spinal) and one motor nucleus
- Supratrigeminal nucleus acts as a pattern generator for mastication rhythm
- Sensory nuclei merge at pons to form a sensory root
- Motor nucleus forms a motor root
- Sensory root expands into the trigeminal ganglion in the middle cranial fossa
- Trigeminal ganglion is located in the trigeminal cave, lateral to the cavernous sinus
- Trigeminal ganglion gives rise to 3 divisions: ophthalmic (V1), maxillary (V2), and mandibular (V3)
- Motor root passes inferiorly to the sensory root and is only distributed to the mandibular division
- Ophthalmic and maxillary nerves travel laterally to the cavernous sinus
- Ophthalmic exits via the superior orbital fissure
- Maxillary exits via the foramen rotundum
- Mandibular exits via the foramen ovale and enters the infra-temporal fossa
Ophthalmic Nerve (V1)
- Travels laterally to the cavernous sinus
- Gives rise to the recurrent tentorial branch (supplies tentorium cerebelli)
- Exits the cranium via the superior orbital fissure
- Divides into three branches: frontal, lacrimal, and nasociliary
Ophthalmic Nerve Function
- Sensory: Forehead, scalp, frontal, ethmoid and sphenoid sinuses, upper eyelid and conjunctiva, cornea, dorsum of nose, lacrimal gland, parts of meninges and tentorium cerebelli
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Autonomic: Does not contain autonomic fibers. Sympathetic and parasympathetic fibers hitchhike on CNV1
- Sympathetic: From superior cervical ganglion, travel on branches of nasociliary nerve (long ciliary nerves) to reach dilator pupillae in the eye
- Parasympathetic: From pterygopalatine ganglion, travel along zygomatic branch of maxillary nerve (CNV2) and then lacrimal branch of ophthalmic nerve (CNV1) to reach the lacrimal gland
Maxillary Nerve (V2)
- Second branch of trigeminal nerve
- Sensory supply to middle third of the face
- Passes through the lateral wall of the cavernous sinus
- Exits skull through the foramen rotundum
Maxillary Nerve Branches
- Superior alveolar nerve (anterior, posterior, and middle)
- Middle meningeal nerve
- Infraorbital nerve
- Zygomatic nerve (Zygomaticofacial & Zygomatictemporal)
- Inferior palpebral nerve, Superior labial nerve, and nasal nerve
- Pharyngeal nerve
- Greater and lesser palatine nerves
- Nasopalatine Nerve
Maxillary Nerve Function
- Sensory: Lower eyelid and its conjunctiva, inferior posterior portion of nasal cavity, cheeks and maxillary sinus, lateral nose, upper lip, teeth and gingiva, superior palate
- Parasympathetic: Post-ganglionic fibers from pterygopalatine ganglion (derived from facial nerve) travel with maxillary nerve to lacrimal gland and nasal glands
Mandibular Nerve (V3)
- Has sensory, motor, and parasympathetic functions
- Motor root runs along the floor of the trigeminal cave, beneath the ganglion, and joins the sensory root before leaving the cranium through the foramen ovale
Mandibular Nerve Branches
- Auriculotemporal Nerve
- Buccal Nerve
- Inferior Alveolar Nerve
- Lingual Nerve
Auriculotemporal Nerve
- Arises from two roots: superior (sensory fibers) and inferior (parasympathetic fibers from CN IX to the parotid gland)
- Secretory-motor fibers run to synapse in the otic ganglion
- Sensory fibers pass through the ganglion and innervate the anterior part of the auricle, lateral part of the temple, and anterior external meatus
Buccal Nerve
- Contains sensory fibers
- Passes between two heads of the lateral pterygoid muscle
- Provides general sensory innervation to buccal membranes of the mouth, second and third molar teeth
Inferior Alveolar Nerve
- Contains sensory and motor fibers
- Gives rise to the mylohyoid nerve (motor to mylohyoid and anterior digastric muscles)
- Remaining sensory fibers enter the mandibular canal
- Provides branches to mandibular teeth
- Emerges through the mental foramen as the mental nerve (sensory innervation to lower lip and chin)
Lingual Nerve
- Contains general sensory, special sensory, and autonomic fibers
- General sensory fibers innervate the anterior two-thirds of the tongue
- Special sensory fibers carry taste to the anterior two-thirds of the tongue
- Autonomic fibers branch to synapse in the submandibular ganglion, eventually innervating the submandibular and sublingual glands
Mandibular Nerve Function
- Sensory: Anterior two-thirds of the tongue, branches to mandibular teeth, lower lip and chin, anterior part of auricle, lateral part of the temple, anterior external meatus, buccal membranes of the mouth
- Motor: Mastication muscles, anterior digastric, tensor veli palatini, tensor tympani, mylohyoid
- Parasympathetic: Submandibular and sublingual glands
Clinical Relevance: Damage to Facial Nerve
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Intracranial Lesions: Occur within the intracranial course of the facial nerve (proximal to the stylomastoid foramen)
- Causes: Infection related to the external or middle ear, Bell’s palsy (idiopathic)
- Symptoms: Paralysis or severe weakness of facial expression muscles
- Other symptoms depending on the location of the lesion: reduced salivation and loss of taste on ipsilateral 2/3 of tongue (chorda tympani), ipsilateral hyperacusis (hypersensitive to sound) (nerve to stapedius), ipsilateral reduced lacrimal fluid production (greater petrosal nerve)
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Extracranial Lesions: Occur within the extracranial course of the facial nerve (distal to the stylomastoid foramen)
- Only motor function of facial nerve is affected
- Causes: Parotid gland pathology, infection of the nerve (herpes virus), compression during forceps delivery, Bell’s palsy (idiopathic)
- Symptoms: Paralysis or severe weakness of facial expression muscles
Parasympathetic Nervous System
- Division of the autonomic nervous system
- Involuntary actions, works with sympathetic nervous system to maintain homeostasis
- Associated with the ‘rest and digest’ response
- Fibers begin in the central nervous system (CNS)
- Nerves supplying the head and neck are located within 4 nuclei in the brainstem, associated with cranial nerves 3, 7, 9, and 10
Parasympathetic Ganglia
- Ciliary Ganglion: Associated with CN III (Oculomotor Nerve)
- Pterygopalatine Ganglion: Associated with CN VII (Facial Nerve)
- Submandibular Ganglion: Associated with CN VII (Facial Nerve)
- Otic Ganglion: Associated with CN IX (Glossopharyngeal Nerve)
Sympathetic Nervous System
- Division of the autonomic nervous system
- Works with the parasympathetic nervous system to maintain homeostasis
- Associated with the ‘fight or flight’ response
Sympathetic Ganglia
- Superior Cervical Ganglion
- Middle Cervical Ganglion
- Inferior Cervical Ganglion
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Description
Dive into the detailed functions and anatomical course of the trigeminal nerve, the largest cranial nerve. Learn about its sensory and motor branches, as well as the nuclei involved in its operation. This quiz covers essential information about the fifth cranial nerve and its significance in sensory and motor innervation.
