HN 30. The trigeminal nerve and its three divisions
Anatomy, MBBS Second Year. This chapter is split into 4 topics and has
171 practice questions. The topics covered are listed below, followed by
10 free sample questions from the chapter.
Topics in this chapter
Origin, nuclei and the ophthalmic nerve40 questions
The maxillary nerve: course, distribution and ganglion branches44 questions
The mandibular nerve: roots, trunk and divisions52 questions
Trigeminal lesion and trigeminal neuralgia35 questions
Sample questions: HN 30. The trigeminal nerve and its three divisions
10 sample questions with the correct answer and an explanation. Try to answer each one before reading the explanation.
Q1. Which branches arise from the nasociliary nerve?
A. The sensory root to the ciliary ganglion, long ciliary nerves, posterior ethmoidal nerve, anterior ethmoidal nerve and infratrochlear nerve(correct answer)
B. The supratrochlear and supraorbital nerves
C. The zygomatic and infraorbital nerves
D. The lacrimal and frontal nerves
Answer: A.Nasociliary nerve branches: (1) sensory root to the ciliary ganglion; (2) long ciliary nerves (sympathetic to the dilator pupillae; sensory to the cornea and iris); (3) posterior ethmoidal nerve — to the sphenoid and ethmoidal sinuses and dura; (4) anterior ethmoidal nerve — to the nasal cavity and dura mater; (5) infratrochlear nerve.
Q2. Which statement summarises the trigeminal origin and its ophthalmic division?
A. The ophthalmic division carries motor fibres to the masseter
B. It arises from a single sensory nucleus
C. Its ophthalmic division supplies the lower eyelid and cheek
D. The trigeminal nerve arises from 4 nuclei (motor — pons; spinal — medulla/pain; main sensory — pons/touch; mesencephalic — midbrain/proprioception) and its ophthalmic division supplies the dura, lacrimal gland, upper eyelid, scalp, cornea, iris, ethmoidal sinuses and nasal cavity(correct answer)
Answer: D.Trigeminal origins: motor nucleus (pons → muscles of mastication) and three sensory nuclei (spinal — medulla, pain; main sensory — pons, touch; mesencephalic — midbrain, proprioception). The ophthalmic division (from the trigeminal ganglion, via the lateral wall of the cavernous sinus and superior orbital fissure) supplies the dura, lacrimal gland, upper eyelid, scalp, cornea, iris, ethmoidal/sphenoid sinuses, nasal cavity and dura.
Q3. Which three branches does the posterior superior nasal branch give inside the nasal cavity, and what does the nasopalatine nerve supply?
A. The nasopalatine nerve supplies the soft palate
B. The medial, lateral and inferior nasal branches
C. The medial nasal branch (medial side of the nasal cavity), the lateral nasal branch (lateral side of the nasal cavity) and the nasopalatine nerve — which crosses the incisive fossa and supplies the anterior hard palate(correct answer)
D. The medial nasal branch supplies the orbit
Answer: C.The posterior superior nasal branch enters the nasal cavity through the sphenopalatine foramen and gives: (i) medial nasal branch — medial side of the nasal cavity; (ii) lateral nasal branch — lateral side of the nasal cavity; (iii) nasopalatine nerve — crosses through the incisive fossa and supplies the anterior hard palate.
Q4. Which statement about the maxillary nerve is correct?
A. It leaves through the foramen ovale and supplies the lower teeth
B. It is purely motor to the muscles of mastication
C. It leaves the skull through the foramen rotundum, crosses the pterygopalatine and infratemporal fossae and the inferior orbital fissure to emerge at the infraorbital foramen, supplying the mid-face skin, upper teeth, palate and nasal cavity via its branches including the zygomatic, alveolar and pterygopalatine ganglionic branches(correct answer)
D. It supplies the forehead and upper eyelid
Answer: C.Maxillary nerve: foramen rotundum → pterygopalatine fossa → pterygomaxillary fissure → infratemporal fossa → inferior orbital fissure → infraorbital groove/canal/foramen. Branches: meningeal, ganglionic, zygomatic, posterior/middle/anterior superior alveolar and terminal palpebral, nasal and labial — supplying the mid-face, upper teeth and gingiva, hard and soft palate, nasal cavity, orbital cavity, tympanic tube and tubal tonsil.
Q5. Which statement summarises the maxillary nerve's distribution?
A. It supplies the tongue and lower teeth
B. It supplies the mid-face skin (inferior palpebra and conjunctiva, nose, upper lip), the upper teeth and gingiva via the three superior alveolar nerves, the hard palate (greater palatine/posterior superior alveolar), the soft palate (lesser palatine), the nasal cavity (posterior superior nasal branches), the orbit (orbital branch), the nasopharynx and tympanic tube, and carries parasympathetic fibres to the lacrimal gland via the zygomaticotemporal nerve(correct answer)
C. It supplies only the upper lip
D. It carries motor fibres to the masseter
Answer: B.Maxillary nerve distribution (from the summary table): meningeal branch — dura; zygomatic (zygomaticotemporal — temple, with parasympathetic to the lacrimal nerve; zygomaticofacial — cheek); infraorbital (inferior palpebral — lower lid and conjunctiva; nasal — nose; superior labial — upper lip; MSAN — premolars and gingiva; ASAN — canines/incisors); posterior superior alveolar — hard palate, molars, gingiva; pterygopalatine branches (nasopharyngeal — tympanic tube and tubal tonsil; orbital — orbital cavity; lesser palatine — soft palate; greater palatine — posterior hard palate; posterior superior nasal — nasal cavity; nasopalatine — anterior hard palate).
Q6. Which statement about the mandibular nerve is correct?
A. It arises by a motor root (motor nucleus) and a sensory root (trigeminal ganglion), passes through the foramen ovale, divides into anterior (muscular + buccal) and posterior (auriculotemporal, lingual, inferior alveolar) divisions, and its trunk gives the nerve to the medial pterygoid and nervus spinosus(correct answer)
B. It is purely sensory
C. It supplies only the tongue
D. It passes through the foramen rotundum
Answer: A.Mandibular nerve: roots — motor (from the motor nucleus) and sensory (from the trigeminal ganglion); course — through the foramen ovale; divisions — anterior (muscles of mastication except medial pterygoid + buccal sensory) and posterior (auriculotemporal, lingual, inferior alveolar); trunk branches — nerve to the medial pterygoid and nervus spinosus.
Q7. Which statement about the inferior alveolar and lingual nerves is correct?
A. The inferior alveolar nerve passes through the mandibular foramen, gives the inferior dental, mental and mylohyoid branches, while the lingual nerve joins the chorda tympani (general sensation and taste from the anterior 2/3 of the tongue, with parasympathetic to the salivary glands)(correct answer)
B. The lingual nerve passes through the foramen ovale
C. The inferior alveolar nerve supplies the tongue
D. The lingual nerve supplies the lower teeth
Answer: A.Inferior alveolar nerve — through the mandibular foramen, giving the inferior dental nerves (inferior teeth), mental nerve (chin skin) and mylohyoid nerve (mylohyoid and anterior belly of digastric). Lingual nerve — joins the chorda tympani, gives general sensation from the anterior 2/3 of the tongue, and its chorda tympani fibres give taste from the anterior 2/3 plus parasympathetic supply to the submandibular and sublingual glands.
Q8. Which statement about trigeminal neuralgia is correct?
A. It is a painless loss of sensation
B. It is severe paroxysmal pain along the distribution of a trigeminal branch, commonly V2 and V3, usually due to compression (90% by the superior cerebellar artery) or idiopathic, radiating from the jaw to the ear/eye/nasal cavity, occurring up to 100 times a day and treated with carbamazepine/gabapentin or surgery(correct answer)
C. It causes paralysis of the muscles of mastication
D. It affects only the ophthalmic division
Answer: B.Trigeminal neuralgia: severe pain along a trigeminal branch distribution; due to compression or irritation (tumour/cyst/blood vessel) — 90% by the superior cerebellar artery, 10% idiopathic; commonly V2 and V3; pain radiates from the jaw to the ear, eye and nasal cavity, up to 100 times/day lasting seconds to minutes; treated with carbamazepine/gabapentin or by decompression/radiofrequency ablation.
Q9. Which statement summarises the trigeminal nerve?
A. Its three divisions are all purely sensory
B. It is a purely motor nerve
C. It supplies the facial muscles
D. It arises from 4 nuclei, divides into ophthalmic (sensory: upper face, eye, nose, dura), maxillary (sensory: mid-face, upper teeth, palate) and mandibular (sensory + motor to muscles of mastication) divisions; lesions cause ipsilateral sensory loss and masticator paralysis, while neuralgia causes paroxysmal pain(correct answer)
Answer: D.Trigeminal nerve: 4 nuclei (1 motor, 3 sensory); divisions — ophthalmic (V1, sensory to upper face/eye/dura), maxillary (V2, sensory to mid-face/upper teeth/palate/nasal cavity) and mandibular (V3, sensory to lower face/tongue/teeth plus motor to the muscles of mastication). Lesions — ipsilateral loss of sensation and masticator paralysis; neuralgia — severe paroxysmal pain.
Q10. Which statement summarises the trigeminal nerve clinically?
A. A trigeminal lesion paralyses the ipsilateral muscles of mastication and abolishes all facial sensation on that side (with TMJ problems), while trigeminal neuralgia causes excruciating paroxysmal pain along a division — commonly V2/V3, 90% due to superior cerebellar artery compression, treated with carbamazepine/gabapentin or surgery(correct answer)
B. Trigeminal lesions spare sensation
C. A trigeminal lesion causes facial paralysis
D. Trigeminal neuralgia is painless
Answer: A.Trigeminal lesion — paralysis of the muscles of mastication on the same side, loss of all sensations on the same side of the face and problematic TMJ. Trigeminal neuralgia — severe paroxysmal pain along a branch (commonly V2 and V3), due to compression or irritation (90% SCA, 10% idiopathic), radiating from the jaw to the ear/eye/nasal cavity, up to 100 times/day for seconds to minutes; treated with carbamazepine/gabapentin, or surgically by decompression/radiofrequency ablation.