Chapter: Neuroanatomy; Topic: Brainstem Circulation; Subtopic: Arterial Supply of the Medulla Oblongata
Keyword Definitions:
Medulla oblongata: The lowest part of the brainstem, controlling vital functions like breathing, heart rate, and reflexes such as swallowing and coughing.
Vertebral artery: A branch of the subclavian artery that ascends through the cervical vertebrae to supply the brainstem and cerebellum.
Anterior spinal artery: Formed by branches of the vertebral arteries, supplying the anterior two-thirds of the medulla and spinal cord.
Basilar artery: Formed by the union of the two vertebral arteries, supplying the pons and upper medulla.
Posterior cerebral artery: A branch of the basilar artery that supplies the midbrain and occipital lobes but not the medulla.
Lead Question – 2014
Medulla is supplied by all except?
a) Basilar artery
b) Anterior spinal artery
c) Vertebral artery
d) Posterior cerebral artery
Explanation:
The medulla oblongata is supplied mainly by the vertebral arteries, anterior spinal artery, and posterior inferior cerebellar artery (PICA). The basilar artery contributes minimally to the upper medulla. However, the posterior cerebral artery supplies the midbrain and occipital lobes but does not supply the medulla. Hence, the correct answer is d) Posterior cerebral artery. This vascular arrangement is vital for maintaining vital autonomic functions.
1) Which artery forms the anterior spinal artery?
a) Vertebral artery
b) Basilar artery
c) Posterior inferior cerebellar artery
d) Posterior spinal artery
Explanation: The anterior spinal artery is formed by branches of the vertebral arteries near their junction at the medulla. It runs along the anterior median fissure and supplies the anterior two-thirds of the spinal cord and medulla. Hence, the correct answer is a) Vertebral artery.
2) The posterior inferior cerebellar artery (PICA) is a branch of which artery?
a) Basilar artery
b) Vertebral artery
c) Posterior cerebral artery
d) Internal carotid artery
Explanation: The PICA arises from the vertebral artery before it merges into the basilar artery. It supplies the dorsolateral medulla and inferior part of the cerebellum. Its occlusion results in lateral medullary (Wallenberg’s) syndrome. The correct answer is b) Vertebral artery.
3) Occlusion of which artery causes medial medullary syndrome?
a) Anterior spinal artery
b) Posterior spinal artery
c) Basilar artery
d) Posterior inferior cerebellar artery
Explanation: Medial medullary syndrome occurs due to occlusion of the anterior spinal artery. It affects the pyramids, medial lemniscus, and hypoglossal nerve, leading to contralateral hemiplegia, loss of proprioception, and ipsilateral tongue paralysis. Hence, the correct answer is a) Anterior spinal artery.
4) Which artery does not directly contribute to the blood supply of the medulla?
a) Vertebral artery
b) Posterior cerebral artery
c) Basilar artery
d) Anterior spinal artery
Explanation: The posterior cerebral artery supplies the midbrain, thalamus, and occipital cortex, but not the medulla. The vertebral, basilar, and anterior spinal arteries all supply portions of the medulla. Hence, the correct answer is b) Posterior cerebral artery.
5) A patient presents with hoarseness, loss of gag reflex, and contralateral body sensory loss. Which artery is most likely affected?
a) Anterior spinal artery
b) Posterior inferior cerebellar artery
c) Basilar artery
d) Posterior cerebral artery
Explanation: These are classic features of lateral medullary (Wallenberg’s) syndrome due to occlusion of the PICA. It affects the nucleus ambiguus, spinal tract of the trigeminal nerve, and spinothalamic tract. Hence, the correct answer is b) Posterior inferior cerebellar artery.
6) The basilar artery is formed by the union of which arteries?
a) Internal carotid arteries
b) Vertebral arteries
c) Anterior spinal arteries
d) Posterior cerebral arteries
Explanation: The basilar artery is formed by the union of the two vertebral arteries at the level of the pontomedullary junction. It ascends on the ventral surface of the pons and gives off branches to the pons, cerebellum, and inner ear. Hence, the correct answer is b) Vertebral arteries.
7) A 60-year-old man presents with tongue deviation to one side and contralateral hemiplegia. The lesion involves which artery?
a) Basilar artery
b) Anterior spinal artery
c) Posterior inferior cerebellar artery
d) Posterior cerebral artery
Explanation: The symptoms indicate medial medullary syndrome due to occlusion of the anterior spinal artery. It damages the hypoglossal nerve, pyramid, and medial lemniscus. Tongue deviation occurs ipsilaterally, and contralateral weakness occurs due to corticospinal tract involvement. Correct answer: b) Anterior spinal artery.
8) Which of the following arteries supplies the dorsal medulla including the gracile and cuneate nuclei?
a) Posterior spinal artery
b) Anterior spinal artery
c) Vertebral artery
d) Basilar artery
Explanation: The posterior spinal arteries supply the dorsal medulla, particularly the gracile and cuneate nuclei. These arteries arise from either the vertebral arteries or posterior inferior cerebellar arteries. Their occlusion leads to sensory loss for fine touch and proprioception. Hence, the correct answer is a) Posterior spinal artery.
9) A stroke involving the vertebral artery may present with which of the following symptoms?
a) Contralateral limb paralysis and ipsilateral facial weakness
b) Dysphagia, hoarseness, and ataxia
c) Aphasia and hemianopia
d) Facial numbness and upper limb weakness
Explanation: Vertebral artery occlusion can cause lateral medullary syndrome with dysphagia, hoarseness, ataxia, and loss of pain and temperature sensation. These features result from involvement of the nucleus ambiguus and inferior cerebellar peduncle. The correct answer is b) Dysphagia, hoarseness, and ataxia.
10) Which artery is commonly affected in brainstem infarction at the pontomedullary junction?
a) Basilar artery
b) Posterior cerebral artery
c) Anterior spinal artery
d) Posterior inferior cerebellar artery
Explanation: The basilar artery supplies the pons and upper medulla at the pontomedullary junction. Infarction here may cause cranial nerve deficits (VI, VII) and contralateral motor weakness. The posterior cerebral artery does not supply this region. Hence, the correct answer is a) Basilar artery.
Chapter: Ear Anatomy; Topic: Middle Ear; Subtopic: Eustachian Tube
Keyword Definitions:
Eustachian Tube: A canal connecting the middle ear to the nasopharynx, which equalizes air pressure.
Middle Ear: The air-filled cavity containing ossicles (malleus, incus, stapes).
Nasopharynx: The upper part of the pharynx connecting with the nasal cavity.
Auditory Function: Refers to sound transmission and pressure equalization in the ear.
Lead Question - 2014
Length of Eustachian tube?
a) 12 mm
b) 24 mm
c) 36 mm
d) 48 mm
Explanation:
The Eustachian tube measures approximately 36 mm (3.6 cm) in adults, connecting the middle ear to the nasopharynx. It is divided into a bony (posterior one-third) and cartilaginous (anterior two-thirds) part. It helps equalize air pressure across the tympanic membrane and drains secretions from the middle ear. Hence, the correct answer is 36 mm (c).
1) Which part of the Eustachian tube is bony?
a) Anterior one-third
b) Posterior one-third
c) Entire tube
d) Only at the junction
The posterior one-third of the Eustachian tube is bony and lies in the petrous part of the temporal bone, while the anterior two-thirds are cartilaginous. This structure maintains patency and supports middle ear ventilation. Hence, the correct answer is b) Posterior one-third.
2) Which muscle helps in opening the Eustachian tube during swallowing?
a) Tensor tympani
b) Stapedius
c) Tensor veli palatini
d) Levator veli palatini
The tensor veli palatini muscle is the main opener of the Eustachian tube during swallowing and yawning. This action allows equalization of pressure between the middle ear and nasopharynx, essential for hearing balance. Hence, the correct answer is c) Tensor veli palatini.
3) Eustachian tube connects middle ear with?
a) Oropharynx
b) Nasopharynx
c) External auditory canal
d) Inner ear
The Eustachian tube connects the middle ear cavity to the nasopharynx. It ensures equal air pressure across both sides of the tympanic membrane and aids in drainage. Dysfunction may lead to otitis media or hearing issues. Hence, the correct answer is b) Nasopharynx.
4) Eustachian tube is lined by?
a) Stratified squamous epithelium
b) Simple squamous epithelium
c) Ciliated columnar epithelium
d) Cuboidal epithelium
The Eustachian tube is lined by ciliated columnar epithelium with goblet cells that help clear mucus and debris into the nasopharynx. This mucociliary clearance maintains ear health and prevents infection. Hence, the correct answer is c) Ciliated columnar epithelium.
5) The angle formed by the Eustachian tube with the horizontal plane in adults is approximately?
a) 10°
b) 20°
c) 30°
d) 45°
In adults, the Eustachian tube makes an angle of about 45° with the horizontal plane, while in children it is shorter and more horizontal. This anatomical difference predisposes children to middle ear infections. Hence, the correct answer is d) 45°.
6) (Clinical) Blockage of the Eustachian tube leads to?
a) Conductive hearing loss
b) Sensorineural hearing loss
c) Central hearing loss
d) Vestibular dysfunction
Blockage of the Eustachian tube causes conductive hearing loss due to fluid accumulation and pressure imbalance in the middle ear. This can occur during colds, allergies, or infections. It often resolves with decongestants or by treating underlying causes. Hence, the correct answer is a) Conductive hearing loss.
7) (Clinical) A child with recurrent ear infections most likely has a Eustachian tube that is?
a) Short and vertical
b) Long and horizontal
c) Short and horizontal
d) Long and vertical
Children have a short and horizontal Eustachian tube, which allows easier spread of infections from the nasopharynx to the middle ear. This anatomical factor is a key reason for recurrent otitis media in children. Hence, the correct answer is c) Short and horizontal.
8) (Clinical) Eustachian tube dysfunction causes which of the following symptoms?
a) Vertigo
b) Tinnitus
c) Diplopia
d) Nystagmus
Tinnitus, or ringing in the ears, is a common symptom of Eustachian tube dysfunction due to altered pressure dynamics and fluid buildup. It may accompany a feeling of fullness, muffled hearing, or popping sounds. Hence, the correct answer is b) Tinnitus.
9) (Clinical) Patulous Eustachian tube refers to?
a) Blocked tube
b) Permanently open tube
c) Shortened tube
d) Inflamed tube
A patulous Eustachian tube remains abnormally open, allowing voice and breathing sounds to be heard loudly in the ear (autophony). It may occur due to weight loss, hormonal changes, or dehydration. Hence, the correct answer is b) Permanently open tube.
10) (Clinical) In otitis media with effusion, which structure’s function is impaired?
a) Tympanic membrane
b) Cochlea
c) Eustachian tube
d) Semicircular canal
In otitis media with effusion, the Eustachian tube fails to ventilate and drain the middle ear, causing fluid buildup and muffled hearing. This dysfunction often follows infections or allergies. Treatment aims to restore tube patency. Hence, the correct answer is c) Eustachian tube.
Chapter: Nervous System; Topic: Cranial Nerves; Subtopic: Parasympathetic Pathways to Lacrimal Gland
Keyword Definitions:
Lacrimal gland: Exocrine gland that secretes tears to lubricate and protect the eye.
Parasympathetic supply: Autonomic fibers responsible for secretory stimulation of glands.
Greater petrosal nerve: A branch of the facial nerve that carries parasympathetic fibers to the lacrimal gland.
Pterygopalatine ganglion: A parasympathetic ganglion where preganglionic fibers from the facial nerve synapse before reaching the lacrimal gland.
Lead Question - 2014
Parasympathetic supply to lacrimal glands are passed through?
a) Lesser petrosal nerve
b) Chorda tympani
c) Greater petrosal nerve
d) Lingual nerve
Explanation:
The parasympathetic fibers to the lacrimal gland originate from the superior salivatory nucleus of the facial nerve. They travel via the greater petrosal nerve, synapse in the pterygopalatine ganglion, and then reach the lacrimal gland through the zygomatic and lacrimal nerves. This pathway controls tear secretion. Hence, the correct answer is c) Greater petrosal nerve.
1) Which ganglion is involved in the parasympathetic pathway to the lacrimal gland?
a) Ciliary ganglion
b) Otic ganglion
c) Pterygopalatine ganglion
d) Submandibular ganglion
The pterygopalatine ganglion (also called sphenopalatine) is where the preganglionic parasympathetic fibers from the greater petrosal nerve synapse. Postganglionic fibers then reach the lacrimal gland via the zygomatic branch of the maxillary nerve. Hence, the correct answer is c) Pterygopalatine ganglion.
2) The greater petrosal nerve is a branch of which cranial nerve?
a) Trigeminal
b) Facial
c) Glossopharyngeal
d) Vagus
The greater petrosal nerve arises from the facial nerve (cranial nerve VII) at the geniculate ganglion. It carries preganglionic parasympathetic fibers to the pterygopalatine ganglion, which later innervate the lacrimal and nasal glands. Hence, the correct answer is b) Facial nerve.
3) Which nerve carries postganglionic fibers to the lacrimal gland?
a) Zygomatic nerve
b) Auriculotemporal nerve
c) Lingual nerve
d) Nasociliary nerve
After synapsing in the pterygopalatine ganglion, postganglionic fibers travel via the zygomatic nerve (branch of V2) and join the lacrimal nerve (branch of V1) to reach the lacrimal gland. Hence, the correct answer is a) Zygomatic nerve.
4) Which cranial nucleus gives origin to fibers supplying the lacrimal gland?
a) Inferior salivatory nucleus
b) Superior salivatory nucleus
c) Edinger-Westphal nucleus
d) Dorsal motor nucleus of vagus
The superior salivatory nucleus of the pons provides preganglionic parasympathetic fibers that travel through the facial nerve and greater petrosal nerve to reach the lacrimal gland, promoting tear secretion. Hence, the correct answer is b) Superior salivatory nucleus.
5) (Clinical) Damage to the greater petrosal nerve results in?
a) Loss of taste
b) Dryness of eyes
c) Hyperlacrimation
d) Facial palsy
Injury to the greater petrosal nerve disrupts parasympathetic innervation to the lacrimal gland, leading to dryness of the eye due to reduced tear secretion. This may occur in facial nerve lesions proximal to the geniculate ganglion. Hence, the correct answer is b) Dryness of eyes.
6) (Clinical) A lesion at the geniculate ganglion affects which functions?
a) Lacrimation and taste
b) Hearing only
c) Facial sensation
d) Eye movements
A lesion at the geniculate ganglion affects both lacrimation (greater petrosal nerve) and taste (chorda tympani). Patients may present with dry eyes and loss of taste on the anterior two-thirds of the tongue. Hence, the correct answer is a) Lacrimation and taste.
7) (Clinical) Which symptom indicates greater petrosal nerve damage in facial palsy?
a) Loss of corneal reflex
b) Decreased lacrimation
c) Hyperacusis
d) Vertigo
In facial palsy affecting the segment proximal to the greater petrosal nerve, decreased lacrimation occurs due to interruption of parasympathetic fibers to the lacrimal gland. Hence, the correct answer is b) Decreased lacrimation.
8) (Clinical) A patient with Bell’s palsy complains of dry eyes. Which structure is likely involved?
a) Chorda tympani
b) Greater petrosal nerve
c) Stapedius branch
d) Temporal branch of facial nerve
Dry eyes in Bell’s palsy suggest involvement of the greater petrosal nerve due to interruption of parasympathetic supply to the lacrimal gland. This differentiates proximal from distal facial nerve lesions. Hence, the correct answer is b) Greater petrosal nerve.
9) (Clinical) Which condition may cause excessive tearing (epiphora) despite normal nerve function?
a) Blocked nasolacrimal duct
b) Facial nerve palsy
c) Damage to pterygopalatine ganglion
d) Geniculate ganglion lesion
Excessive tearing, or epiphora, usually results from a blocked nasolacrimal duct, preventing proper tear drainage into the nasal cavity. The parasympathetic pathway remains intact. Hence, the correct answer is a) Blocked nasolacrimal duct.
10) (Clinical) Which condition is characterized by dry eyes and mouth due to autoimmune destruction of lacrimal and salivary glands?
a) Myasthenia gravis
b) Sjögren’s syndrome
c) Bell’s palsy
d) Sarcoidosis
Sjögren’s syndrome causes autoimmune destruction of lacrimal and salivary glands, leading to dry eyes (xerophthalmia) and dry mouth (xerostomia). Parasympathetic pathways remain intact, but glandular tissue is damaged. Hence, the correct answer is b) Sjögren’s syndrome.
Chapter: Head and Neck Anatomy; Topic: Paranasal Sinuses; Subtopic: Onodi Cells and Clinical Significance
Keyword Definitions:
Onodi cells: These are posterior ethmoidal air cells that extend close to or above the sphenoid sinus, sometimes surrounding the optic nerve.
Ethmoidal sinus: A collection of multiple small air cells between the nose and the orbit, divided into anterior and posterior groups.
Sphenoid sinus: A deep paranasal sinus located behind the nasal cavity near vital structures like the optic nerve and internal carotid artery.
Optic nerve: The second cranial nerve responsible for vision, vulnerable to injury during endoscopic sinus surgery involving Onodi cells.
Lead Question - 2014
Onodi cells are seen in?
a) Sphenoid sinus
b) Maxillary sinus
c) Anterior ethmoidal sinus
d) Posterior ethmoidal sinus
Explanation:
Onodi cells are specialized posterior ethmoidal air cells that extend posteriorly and may lie superior or lateral to the sphenoid sinus. Their proximity to the optic nerve makes them clinically significant, as inadvertent injury during sinus surgery can lead to visual loss. Hence, the correct answer is d) Posterior ethmoidal sinus.
1) Onodi cells are closely related to which cranial nerve?
a) Olfactory nerve
b) Optic nerve
c) Oculomotor nerve
d) Trochlear nerve
The optic nerve (cranial nerve II) lies in close proximity to the Onodi cells. Inflammation or surgical injury involving these posterior ethmoidal cells can cause optic neuritis or vision loss. Hence, the correct answer is b) Optic nerve.
2) The posterior ethmoidal sinus drains into which meatus?
a) Middle meatus
b) Superior meatus
c) Inferior meatus
d) Common nasal meatus
The posterior ethmoidal sinus drains into the superior meatus of the nasal cavity. This drainage pathway is clinically important as blockage may cause posterior ethmoid sinusitis, sometimes involving the optic canal region. Hence, the correct answer is b) Superior meatus.
3) Which imaging modality best visualizes Onodi cells?
a) Plain X-ray
b) MRI
c) CT scan (PNS)
d) Ultrasound
A CT scan of paranasal sinuses (PNS) is the best imaging tool to identify Onodi cells. It helps assess their relation to the optic nerve and sphenoid sinus before endoscopic sinus surgery. Hence, the correct answer is c) CT scan (PNS).
4) (Clinical) During endoscopic sinus surgery, which complication may arise due to unrecognized Onodi cells?
a) Diplopia
b) Vision loss
c) Epistaxis
d) Otitis media
Unrecognized Onodi cells can lead to inadvertent injury to the optic nerve during surgery, resulting in vision loss. This makes preoperative imaging critical for surgical safety. Hence, the correct answer is b) Vision loss.
5) (Clinical) A patient presents with retro-orbital pain and vision loss following sinus infection. Which sinus is likely involved?
a) Maxillary
b) Frontal
c) Posterior ethmoidal (Onodi cells)
d) Anterior ethmoidal
Infection involving Onodi cells (posterior ethmoidal sinus) can spread to the optic nerve causing retro-orbital pain and vision loss. This condition requires urgent management to prevent permanent blindness. Hence, the correct answer is c) Posterior ethmoidal (Onodi cells).
6) The sphenoid sinus opens into which region of the nasal cavity?
a) Superior meatus
b) Middle meatus
c) Sphenoethmoidal recess
d) Inferior meatus
The sphenoid sinus opens into the sphenoethmoidal recess above the superior concha. This anatomical relation helps distinguish it from the posterior ethmoidal sinus. Hence, the correct answer is c) Sphenoethmoidal recess.
7) (Clinical) Which artery is at risk during posterior ethmoidal sinus surgery?
a) Anterior ethmoidal artery
b) Posterior ethmoidal artery
c) Sphenopalatine artery
d) Facial artery
The posterior ethmoidal artery runs near the roof of the posterior ethmoidal sinus and may be injured during surgery, leading to epistaxis or orbital hematoma. Hence, the correct answer is b) Posterior ethmoidal artery.
8) Which sinus is most commonly infected in sinusitis?
a) Maxillary
b) Sphenoid
c) Posterior ethmoidal
d) Frontal
The maxillary sinus is the most commonly infected sinus due to its poor drainage and dependency on gravity. Ethmoidal and frontal sinus infections are less frequent but can have severe complications. Hence, the correct answer is a) Maxillary.
9) (Clinical) Orbital cellulitis due to ethmoidal sinusitis commonly spreads through?
a) Lamina papyracea
b) Nasolacrimal duct
c) Frontal recess
d) Cribriform plate
Ethmoidal sinusitis can spread to the orbit via the lamina papyracea, a thin bony wall separating the ethmoid sinus from the orbit. This can cause orbital cellulitis, a vision-threatening condition. Hence, the correct answer is a) Lamina papyracea.
10) (Clinical) A surgeon accidentally damages the optic canal during sinus surgery. Which structure is most likely affected?
a) Ophthalmic artery
b) Oculomotor nerve
c) Optic nerve
d) Abducent nerve
The optic nerve and ophthalmic artery pass through the optic canal. Damage to this region during endoscopic sinus surgery, especially near Onodi cells, can result in immediate visual loss. Hence, the correct answer is c) Optic nerve.
Chapter: Ear, Nose, and Throat (ENT); Topic: Paranasal Sinuses; Subtopic: Anatomical Variations of Sinuses
Keyword Definitions:
Haller Cells: Infraorbital ethmoidal air cells located along the floor of the orbit that can narrow the maxillary sinus ostium.
Onodi Cells: Posterior ethmoidal cells that extend close to the optic nerve and sphenoid sinus.
Paranasal Sinuses: Air-filled spaces within facial bones surrounding the nasal cavity, including maxillary, frontal, ethmoidal, and sphenoidal sinuses.
Ethmoidal Sinus: Group of air cells between the nose and orbit divided into anterior and posterior groups.
Maxillary Sinus: Largest paranasal sinus, located within the maxilla, opening into the middle meatus of the nasal cavity.
Lead Question – 2014
Haller cells are seen in?
a) Roof of nose
b) Orbital floor
c) Lateral nasal wall
d) Maxillary sinus
Explanation: Haller cells are infraorbital ethmoidal air cells located along the orbital floor. They can impinge on the infundibulum and cause obstruction of the maxillary sinus. These cells are important in sinus surgery, as they increase the risk of orbital injury if not identified. Answer: b) Orbital floor.
1) Onodi cells are located near which important structure?
a) Optic nerve
b) Facial nerve
c) Olfactory bulb
d) Internal carotid artery
Explanation: Onodi cells are posterior ethmoidal air cells that extend near the optic nerve and sometimes the internal carotid artery, making surgical navigation in this region critical. Damage may result in visual loss. Answer: a) Optic nerve.
2) The largest paranasal sinus is:
a) Maxillary sinus
b) Frontal sinus
c) Ethmoid sinus
d) Sphenoid sinus
Explanation: The maxillary sinus, located in the body of the maxilla, is the largest of all paranasal sinuses. It drains into the middle meatus via the ostium. Infections here can cause pain in the upper jaw or toothache. Answer: a) Maxillary sinus.
3) Frontal sinus drains into which nasal meatus?
a) Superior meatus
b) Middle meatus
c) Inferior meatus
d) Common meatus
Explanation: The frontal sinus drains through the frontonasal duct into the middle meatus via the hiatus semilunaris. Obstruction may lead to frontal sinusitis. Answer: b) Middle meatus.
4) Which nerve provides sensory supply to maxillary sinus?
a) Infraorbital nerve
b) Nasociliary nerve
c) Auriculotemporal nerve
d) Greater petrosal nerve
Explanation: The maxillary sinus receives sensory innervation from the infraorbital and superior alveolar branches of the maxillary nerve (V2). Pain from sinusitis is often felt in the cheek or upper teeth. Answer: a) Infraorbital nerve.
5) The sinus most commonly infected due to poor drainage is:
a) Maxillary sinus
b) Ethmoidal sinus
c) Frontal sinus
d) Sphenoid sinus
Explanation: The maxillary sinus is most prone to infection because its opening is located high on the medial wall, making gravity drainage difficult. Upper respiratory infections or dental infections may spread here. Answer: a) Maxillary sinus.
6) A patient presents with diplopia after sinus surgery. Which cell was likely injured?
a) Haller cell
b) Agger nasi cell
c) Onodi cell
d) Frontal cell
Explanation: Diplopia after sinus surgery suggests orbital injury, which can occur due to inadvertent damage to a large Haller cell situated near the orbital floor. Its proximity to the orbit makes it a critical landmark. Answer: a) Haller cell.
7) Agger nasi cells are found in relation to which sinus?
a) Frontal sinus
b) Sphenoid sinus
c) Maxillary sinus
d) Ethmoid sinus
Explanation: Agger nasi cells are anterior ethmoidal air cells located just anterior to the frontal recess and are considered the most anterior ethmoidal cells. They can narrow the frontal recess, leading to frontal sinusitis. Answer: a) Frontal sinus.
8) Posterior ethmoidal cells open into:
a) Superior meatus
b) Middle meatus
c) Inferior meatus
d) Common meatus
Explanation: Posterior ethmoidal air cells open into the superior meatus, located below the superior nasal concha. They are near the sphenoid sinus and optic nerve. Answer: a) Superior meatus.
9) Sphenoid sinus opens into:
a) Sphenoethmoidal recess
b) Superior meatus
c) Middle meatus
d) Inferior meatus
Explanation: The sphenoid sinus opens into the sphenoethmoidal recess, located above the superior concha. This sinus is close to vital structures like the optic nerve and pituitary gland. Answer: a) Sphenoethmoidal recess.
10) A patient with chronic sinusitis shows mucosal thickening in infraorbital region on CT. Which cell is involved?
a) Haller cell
b) Onodi cell
c) Agger nasi cell
d) Frontal cell
Explanation: Infraorbital mucosal thickening on CT indicates Haller cell involvement. These cells can narrow the maxillary ostium and contribute to sinusitis and orbital symptoms if inflamed. Answer: a) Haller cell.
Chapter: Ear, Nose, and Throat (ENT); Topic: Lacrimal Apparatus; Subtopic: Anatomy and Physiology of Nasolacrimal Duct
Keyword Definitions:
Nasolacrimal Duct: A tubular passage that drains tears from the lacrimal sac into the inferior nasal meatus of the nasal cavity.
Hasner’s Valve: A mucosal fold at the opening of the nasolacrimal duct into the inferior meatus, preventing nasal reflux into the duct.
Lacrimal Apparatus: The structures involved in tear secretion and drainage including the lacrimal gland, canaliculi, sac, and nasolacrimal duct.
Dacryocystitis: Infection of the lacrimal sac, often due to blockage of the nasolacrimal duct, leading to pain and swelling near the medial canthus.
Canaliculi: Small channels that collect tears from the puncta and transport them to the lacrimal sac.
Lead Question – 2014
Which valve is present at the opening of nasolacrimal duct?
a) Hasner's valve
b) Heister valve
c) Spiral valve
d) None
Explanation: The valve of Hasner (plica lacrimalis) is a mucosal fold guarding the opening of the nasolacrimal duct into the inferior nasal meatus. It prevents reflux of nasal contents into the lacrimal system. In infants, its failure to open may lead to congenital nasolacrimal duct obstruction. Answer: a) Hasner’s valve.
1) The nasolacrimal duct opens into which part of the nasal cavity?
a) Superior meatus
b) Middle meatus
c) Inferior meatus
d) Sphenoethmoidal recess
Explanation: The nasolacrimal duct opens into the inferior nasal meatus beneath the inferior turbinate. This anatomical positioning allows tears to drain effectively into the nasal cavity. Obstruction may cause epiphora or infection. Answer: c) Inferior meatus.
2) Which structure acts as the reservoir for tears before they drain into the nasolacrimal duct?
a) Lacrimal gland
b) Lacrimal sac
c) Canaliculi
d) Inferior meatus
Explanation: The lacrimal sac acts as a temporary reservoir where tears accumulate from the canaliculi before draining via the nasolacrimal duct into the nasal cavity. Obstruction at this level causes dacryocystitis. Answer: b) Lacrimal sac.
3) The primary cause of congenital nasolacrimal duct obstruction is failure of:
a) Hasner’s valve to open
b) Canaliculus to form
c) Lacrimal gland secretion
d) Inferior turbinate to regress
Explanation: Congenital nasolacrimal duct obstruction occurs when Hasner’s valve fails to open after birth. This results in pooling of tears, recurrent discharge, and infection in infants. Answer: a) Hasner’s valve to open.
4) In dacryocystorhinostomy (DCR), the new opening is created between:
a) Lacrimal gland and nasal cavity
b) Lacrimal sac and nasal cavity
c) Lacrimal sac and conjunctiva
d) Canaliculus and nasal cavity
Explanation: Dacryocystorhinostomy (DCR) involves creating a direct opening between the lacrimal sac and the nasal cavity, bypassing the blocked nasolacrimal duct. This allows normal tear drainage and relieves chronic dacryocystitis. Answer: b) Lacrimal sac and nasal cavity.
5) Which nerve supplies parasympathetic fibers to the lacrimal gland?
a) Greater petrosal nerve
b) Lesser petrosal nerve
c) Auriculotemporal nerve
d) Infraorbital nerve
Explanation: The lacrimal gland receives parasympathetic fibers from the greater petrosal nerve, a branch of the facial nerve (VII). These fibers enhance tear secretion. Damage may cause dry eye. Answer: a) Greater petrosal nerve.
6) A 3-month-old infant presents with persistent watery discharge from the eye. Most likely diagnosis?
a) Congenital nasolacrimal duct obstruction
b) Conjunctivitis
c) Keratitis
d) Blepharitis
Explanation: Persistent tearing and discharge in infants typically indicate congenital nasolacrimal duct obstruction due to non-canalization of Hasner’s valve. It usually resolves spontaneously or with massage. Answer: a) Congenital nasolacrimal duct obstruction.
7) The bone forming the majority of the nasolacrimal canal is:
a) Maxilla
b) Lacrimal bone
c) Ethmoid bone
d) Inferior turbinate
Explanation: The nasolacrimal canal is formed mainly by the maxilla, while the lacrimal bone contributes partially. This canal houses the nasolacrimal duct, draining tears into the inferior meatus. Answer: a) Maxilla.
8) Which of the following valves prevents reflux of tears from the lacrimal sac to the canaliculi?
a) Valve of Rosenmüller
b) Valve of Hasner
c) Valve of Krause
d) Valve of Heister
Explanation: The valve of Rosenmüller is located at the junction of the common canaliculus and lacrimal sac, preventing backflow of tears from the sac into the canaliculi. Answer: a) Valve of Rosenmüller.
9) In chronic dacryocystitis, the common causative organism is:
a) Staphylococcus aureus
b) Streptococcus pneumoniae
c) Pseudomonas aeruginosa
d) E. coli
Explanation: Chronic dacryocystitis is commonly caused by Streptococcus pneumoniae or Staphylococcus species due to obstruction of tear drainage. Recurrent infection leads to mucopurulent discharge and swelling near the medial canthus. Answer: b) Streptococcus pneumoniae.
10) After DCR, persistent epiphora occurs due to obstruction at:
a) Common canaliculus
b) Hasner’s valve
c) Inferior meatus
d) Nasal cavity mucosa
Explanation: Persistent tearing after dacryocystorhinostomy often results from blockage at the common canaliculus or inadequate opening into the nasal cavity. Revision surgery may be required to restore patency. Answer: a) Common canaliculus.
Chapter: Ear, Nose and Throat (ENT); Topic: Nasal Cavity and Paranasal Sinuses; Subtopic: Anatomy of the Ethmoid Bone and Cribriform Plate
Keyword Definitions:
Cribriform Plate: A sieve-like part of the ethmoid bone that forms the roof of the nasal cavity and allows olfactory nerve fibers to pass through to the olfactory bulb.
Olfactory Region: The upper part of the nasal cavity containing olfactory receptors responsible for the sense of smell.
Ethmoid Bone: A light, spongy bone forming part of the anterior cranial fossa, nasal septum, and medial orbital wall.
Anterior Cranial Fossa: The front depression in the skull base housing the frontal lobes of the brain and supported by the ethmoid bone.
Olfactory Nerve (Cranial Nerve I): Transmits sensory input related to smell from the nasal mucosa to the brain via foramina in the cribriform plate.
Lead Question – 2014
Cribriform plate forms?
a) Roof of olfactory region
b) Floor of olfactory region
c) Nasal septum
d) All of the above
Explanation: The cribriform plate of the ethmoid bone forms the roof of the nasal cavity and the floor of the anterior cranial fossa. It is perforated by tiny foramina through which olfactory nerves pass. It supports the olfactory bulb and separates the nasal cavity from the cranial cavity. Answer: a) Roof of olfactory region.
1) Which structure lies directly above the cribriform plate?
a) Frontal lobe
b) Pituitary gland
c) Temporal lobe
d) Cerebellum
Explanation: The cribriform plate forms part of the anterior cranial fossa and lies just below the frontal lobe of the brain. The olfactory bulb rests on its superior surface, receiving sensory input from the nasal mucosa. Answer: a) Frontal lobe.
2) The olfactory nerve fibers pass through:
a) Optic canal
b) Superior orbital fissure
c) Foramina of cribriform plate
d) Foramen rotundum
Explanation: The olfactory nerve fibers pass through multiple small foramina in the cribriform plate of the ethmoid bone to reach the olfactory bulb. These openings allow direct communication between the nasal cavity and cranial cavity. Answer: c) Foramina of cribriform plate.
3) Damage to the cribriform plate may result in:
a) Anosmia
b) Diplopia
c) Deafness
d) Loss of taste
Explanation: Fracture of the cribriform plate may sever olfactory nerve fibers, leading to anosmia (loss of smell). Cerebrospinal fluid rhinorrhea may also occur due to communication between subarachnoid space and nasal cavity. Answer: a) Anosmia.
4) The crista galli is a part of which bone?
a) Frontal bone
b) Ethmoid bone
c) Sphenoid bone
d) Maxilla
Explanation: The crista galli is a vertical projection of the ethmoid bone located above the cribriform plate. It serves as the attachment site for the falx cerebri, a dural fold separating the cerebral hemispheres. Answer: b) Ethmoid bone.
5) Which sinus lies posterior to the cribriform plate?
a) Frontal sinus
b) Sphenoid sinus
c) Ethmoidal air cells
d) Maxillary sinus
Explanation: The ethmoidal air cells lie posterior and lateral to the cribriform plate. These small cavities are part of the ethmoid bone and open into the nasal cavity through the middle and superior meatus. Answer: c) Ethmoidal air cells.
6) A 25-year-old patient presents with clear nasal discharge following head trauma. The likely diagnosis is:
a) CSF rhinorrhea
b) Sinusitis
c) Allergic rhinitis
d) Deviated nasal septum
Explanation: Fracture of the cribriform plate can cause leakage of cerebrospinal fluid (CSF) through the nasal cavity, presenting as clear watery rhinorrhea. This condition is termed CSF rhinorrhea and requires urgent evaluation to prevent meningitis. Answer: a) CSF rhinorrhea.
7) Which bone forms the largest portion of the nasal septum?
a) Vomer
b) Ethmoid
c) Maxilla
d) Palatine
Explanation: The nasal septum is mainly formed by the vomer (posterior and inferior part) and the perpendicular plate of the ethmoid bone (superior part). The septal cartilage completes the anterior portion. Answer: a) Vomer.
8) Which cranial nerve passes through the cribriform plate?
a) CN I
b) CN II
c) CN V
d) CN VII
Explanation: The olfactory nerve (CN I) passes through the small foramina of the cribriform plate to connect the nasal mucosa with the olfactory bulb. It is responsible for the sensation of smell. Answer: a) CN I.
9) Which part of the skull base is most commonly fractured in nasal trauma?
a) Cribriform plate
b) Sella turcica
c) Foramen magnum
d) Mastoid process
Explanation: The thin cribriform plate of the ethmoid bone is highly susceptible to fracture in nasal and facial trauma due to its delicate structure, resulting in CSF rhinorrhea or olfactory loss. Answer: a) Cribriform plate.
10) A patient with anosmia after head injury most likely has damage to:
a) Cribriform plate
b) Optic chiasma
c) Maxilla
d) Zygomatic bone
Explanation: Trauma to the cribriform plate can sever olfactory nerve fibers as they pass through its foramina, resulting in anosmia. This may accompany CSF leakage or infection risk due to cranial-nasal communication. Answer: a) Cribriform plate.
Chapter: Ear, Nose and Throat (ENT); Topic: Larynx; Subtopic: Nerve Supply of the Larynx and Galen’s Anastomosis
Keyword Definitions:
Galen’s Anastomosis: A neural communication between the internal laryngeal nerve and recurrent laryngeal nerve, forming a network supplying sensory and motor innervation to the larynx.
Recurrent Laryngeal Nerve: A branch of the vagus nerve that supplies all intrinsic laryngeal muscles except the cricothyroid and provides sensory supply below the vocal cords.
Internal Laryngeal Nerve: A branch of the superior laryngeal nerve that carries sensory fibers from the mucosa of the larynx above the vocal cords.
External Laryngeal Nerve: A motor branch of the superior laryngeal nerve that supplies the cricothyroid muscle.
Vagus Nerve (Cranial Nerve X): A mixed cranial nerve that provides motor and sensory innervation to structures in the neck, thorax, and abdomen including the larynx.
Lead Question – 2014
Galen’s anastomosis is between?
a) Recurrent laryngeal nerve and external laryngeal nerve
b) Recurrent laryngeal nerve and internal laryngeal nerve
c) Internal laryngeal nerve and external laryngeal nerve
d) None of the above
Explanation: Galen’s anastomosis is a neural communication between the recurrent laryngeal nerve and internal laryngeal nerve. It provides an important sensory and motor coordination within the larynx, ensuring the protection of the airway and phonation. It lies near the posterior cricoarytenoid muscle and maintains reflex connections for vocal cord movement. Answer: b) Recurrent laryngeal nerve and internal laryngeal nerve.
1) The internal laryngeal nerve pierces which membrane?
a) Thyrohyoid membrane
b) Cricothyroid membrane
c) Quadrangular membrane
d) Vocal ligament
Explanation: The internal laryngeal nerve pierces the thyrohyoid membrane along with the superior laryngeal artery to supply sensory fibers to the mucosa of the larynx above the vocal cords and the epiglottis. It also carries taste fibers from the epiglottis. Answer: a) Thyrohyoid membrane.
2) Which muscle of the larynx is supplied by the external laryngeal nerve?
a) Posterior cricoarytenoid
b) Cricothyroid
c) Thyroarytenoid
d) Lateral cricoarytenoid
Explanation: The external laryngeal nerve provides motor supply exclusively to the cricothyroid muscle, which tenses and elongates the vocal cords, aiding in pitch modulation. Injury to this nerve causes voice fatigue and inability to produce high-pitched sounds. Answer: b) Cricothyroid.
3) The recurrent laryngeal nerve supplies sensation to:
a) Above vocal cords
b) Below vocal cords
c) Entire pharynx
d) Nasal cavity
Explanation: The recurrent laryngeal nerve supplies sensory innervation to the mucosa of the larynx below the vocal cords and motor innervation to all intrinsic muscles except cricothyroid. It also provides fibers to the trachea and esophagus. Answer: b) Below vocal cords.
4) Which nerve carries taste sensation from the epiglottis?
a) Glossopharyngeal
b) Internal laryngeal
c) External laryngeal
d) Lingual
Explanation: The internal laryngeal nerve carries both sensory and special taste fibers from the epiglottis and root of the tongue. These fibers are connected to the nucleus tractus solitarius through the vagus nerve. Answer: b) Internal laryngeal.
5) A patient with hoarseness of voice following thyroid surgery likely has injury to:
a) Recurrent laryngeal nerve
b) Internal laryngeal nerve
c) Hypoglossal nerve
d) Facial nerve
Explanation: During thyroid surgery, the recurrent laryngeal nerve is vulnerable to injury due to its close relation to the inferior thyroid artery. Damage results in paralysis of vocal cords leading to hoarseness or voice loss. Answer: a) Recurrent laryngeal nerve.
6) A patient presents with inability to produce high-pitched sounds after thyroid surgery. Which nerve is likely injured?
a) External laryngeal nerve
b) Recurrent laryngeal nerve
c) Internal laryngeal nerve
d) Glossopharyngeal nerve
Explanation: Injury to the external laryngeal nerve affects the cricothyroid muscle, which modulates tension on the vocal cords. This results in a monotonous voice and loss of high-pitched tone, while other vocal cord movements remain intact. Answer: a) External laryngeal nerve.
7) Which branch of the vagus nerve supplies all intrinsic muscles of the larynx except one?
a) Recurrent laryngeal
b) Internal laryngeal
c) External laryngeal
d) Superior laryngeal
Explanation: The recurrent laryngeal nerve supplies all intrinsic laryngeal muscles except the cricothyroid, which is innervated by the external laryngeal nerve. It controls vocal cord abduction, adduction, and relaxation. Answer: a) Recurrent laryngeal.
8) During carotid artery surgery, loss of cough reflex and aspiration may occur due to injury of:
a) Internal laryngeal nerve
b) External laryngeal nerve
c) Recurrent laryngeal nerve
d) Accessory nerve
Explanation: The internal laryngeal nerve provides sensation above the vocal cords and mediates the cough reflex. Damage during carotid or thyroid procedures may lead to aspiration and loss of protective airway reflexes. Answer: a) Internal laryngeal nerve.
9) A 45-year-old male presents with aspiration and hoarseness. Both recurrent laryngeal nerves are involved. Expected finding?
a) Bilateral vocal cord paralysis in adduction
b) Bilateral vocal cord paralysis in abduction
c) Vocal cords fixed in cadaveric position
d) Spasmodic dysphonia
Explanation: Bilateral injury to the recurrent laryngeal nerves causes paralysis of most intrinsic muscles of the larynx, fixing the cords in the paramedian (cadaveric) position. This results in airway obstruction and hoarseness. Answer: c) Vocal cords fixed in cadaveric position.
10) Galen’s anastomosis ensures coordination between:
a) Motor and sensory innervation of the larynx
b) Taste and smell reflexes
c) Cochlear and vestibular pathways
d) Pharyngeal constrictor synchronization
Explanation: Galen’s anastomosis interconnects the internal and recurrent laryngeal nerves, forming a loop that coordinates sensory and motor control of the larynx. It contributes to laryngeal reflexes like cough, swallowing, and phonation by integrating feedback between superior and inferior laryngeal nerves. Answer: a) Motor and sensory innervation of the larynx.
Chapter: Ear, Nose and Throat (ENT); Topic: Paranasal Sinuses; Subtopic: Ethmoidal Sinus and Lamina Papyracea
Keyword Definitions:
Lamina Papyracea: A thin bony plate forming the medial wall of the orbit and lateral wall of the ethmoid sinus, separating both structures.
Ethmoid Sinus: Air cells located between the nasal cavity and orbit, forming part of the ethmoid bone.
Orbit: The bony cavity that houses the eyeball, ocular muscles, nerves, and vessels.
Paranasal Sinuses: Air-filled cavities in the skull that lighten bone weight, produce mucus, and enhance voice resonance.
Orbital Cellulitis: A serious infection that can spread from the ethmoid sinus to the orbit through the lamina papyracea.
Lead Question – 2014
Lamina papyracea is between?
a) Optic nerve and orbit
b) Maxillary sinus and orbit
c) Ethmoid sinus and orbit
d) Cranial cavity and orbit
Explanation: Lamina papyracea is the delicate bony plate that forms the medial wall of the orbit and the lateral wall of the ethmoid sinus. It separates these two cavities and is extremely thin, allowing infections from the ethmoid sinus to easily spread into the orbit, leading to orbital cellulitis. Answer: c) Ethmoid sinus and orbit.
1) Which sinus infection most commonly leads to orbital cellulitis?
a) Maxillary sinus
b) Frontal sinus
c) Ethmoid sinus
d) Sphenoid sinus
Explanation: The ethmoid sinus is separated from the orbit by the thin lamina papyracea. Hence, ethmoid sinusitis can easily spread to the orbital cavity causing orbital cellulitis, especially in children. The close proximity makes this the most frequent site of orbital infection. Answer: c) Ethmoid sinus.
2) The lamina papyracea forms which wall of the orbit?
a) Roof
b) Floor
c) Medial wall
d) Lateral wall
Explanation: The lamina papyracea forms the medial wall of the orbit and is a part of the ethmoid bone. It separates the orbital cavity from the ethmoidal air cells. Due to its thinness, fractures or infections can easily penetrate it. Answer: c) Medial wall.
3) Which bone forms the lamina papyracea?
a) Maxilla
b) Ethmoid
c) Sphenoid
d) Frontal
Explanation: The lamina papyracea is a part of the ethmoid bone, specifically forming the lateral wall of the ethmoid labyrinth. It contributes to the medial orbital wall. Its paper-thin nature gives it the name “papyracea.” Answer: b) Ethmoid.
4) In a CT scan, erosion of the lamina papyracea is most commonly seen in:
a) Maxillary cyst
b) Ethmoid sinusitis
c) Deviated nasal septum
d) Nasal polyps
Explanation: Chronic ethmoid sinusitis can cause thinning or erosion of the lamina papyracea due to persistent inflammation. This may lead to orbital complications like subperiosteal abscess or orbital cellulitis. Imaging is crucial to identify early bone breach. Answer: b) Ethmoid sinusitis.
5) A child presents with periorbital swelling and fever following sinusitis. The most likely structure involved is:
a) Lamina papyracea
b) Frontal bone
c) Zygomatic bone
d) Nasal septum
Explanation: In pediatric patients, infection from ethmoid sinus can easily spread through the lamina papyracea into the orbit causing orbital cellulitis. The bone’s thinness and vascular connections facilitate this spread. Answer: a) Lamina papyracea.
6) Which of the following sinuses lies superior to the orbit?
a) Sphenoid
b) Maxillary
c) Frontal
d) Ethmoid
Explanation: The frontal sinus lies above the orbit and drains into the middle meatus through the frontonasal duct. In contrast, the ethmoid sinus lies medially, the maxillary below, and the sphenoid posteriorly. Answer: c) Frontal.
7) A blow-out fracture of the orbit commonly involves which wall?
a) Roof
b) Floor
c) Medial wall (Lamina papyracea)
d) Lateral wall
Explanation: The floor of the orbit is the most common site for blow-out fractures, often involving the maxillary bone. However, the medial wall (lamina papyracea) can also fracture due to increased intraorbital pressure. Answer: b) Floor.
8) During endoscopic sinus surgery, the lamina papyracea should be preserved to prevent:
a) Orbital injury
b) CSF leak
c) Nasal obstruction
d) Epistaxis
Explanation: The lamina papyracea separates the ethmoid sinus from the orbit. Accidental damage during endoscopic sinus surgery can lead to orbital injury, hematoma, or diplopia due to extraocular muscle entrapment. Hence, it must be carefully preserved. Answer: a) Orbital injury.
9) A CT scan showing an abscess between lamina papyracea and periorbita indicates:
a) Orbital cellulitis
b) Subperiosteal abscess
c) Pott’s puffy tumor
d) Ethmoidal mucocele
Explanation: A subperiosteal abscess occurs when pus collects between the lamina papyracea and the orbital periosteum. It is a complication of ethmoid sinusitis and presents with proptosis and restricted eye movements. Answer: b) Subperiosteal abscess.
10) Which artery is closely related to the lamina papyracea?
a) Anterior ethmoidal artery
b) Posterior ethmoidal artery
c) Maxillary artery
d) Ophthalmic artery
Explanation: The anterior and posterior ethmoidal arteries pass through foramina in the lamina papyracea to supply the ethmoid air cells and nasal cavity. These vessels are branches of the ophthalmic artery and may cause severe bleeding if damaged during sinus surgery. Answer: a) Anterior ethmoidal artery.
Chapter: Head and Neck Anatomy; Topic: Muscles of the Neck; Subtopic: Sternocleidomastoid Muscle
Keyword Definitions:
• Sternocleidomastoid: A paired muscle in the neck that helps in rotation and flexion of the head.
• Accessory Nerve (XI): Provides motor supply to sternocleidomastoid and trapezius muscles.
• Mastoid Process: A conical projection from the temporal bone, providing attachment for sternocleidomastoid.
• Neck Movements: Include flexion, extension, and rotation of the head via cervical muscles.
Lead Question – 2014
False about sternocleidomastoid?
a) Arises from sternum and clavicle
b) Insertes on mastoid process
c) Motor supply by spinal accessory nerve
d) Tilt the head on opposite side
Explanation:
The sternocleidomastoid arises from the manubrium of sternum and medial clavicle, and inserts on the mastoid process. It is supplied by the spinal accessory nerve (motor) and C2–C3 (proprioception). It tilts the head to the same side and rotates to the opposite side. Hence, option (d) is false.
1) Which muscle forms the posterior triangle’s anterior boundary?
a) Trapezius
b) Sternocleidomastoid
c) Platysma
d) Omohyoid
Explanation:
The posterior triangle of the neck is bounded anteriorly by the posterior border of the sternocleidomastoid, posteriorly by the anterior border of the trapezius, and inferiorly by the middle third of the clavicle. The sternocleidomastoid thus forms the anterior boundary. Answer: (b).
2) Which nerve injury causes weakness in turning the head to the opposite side?
a) Hypoglossal nerve
b) Spinal accessory nerve
c) Facial nerve
d) Vagus nerve
Explanation:
The spinal accessory nerve supplies the sternocleidomastoid and trapezius. Injury to this nerve causes weakness in turning the head to the opposite side (due to SCM paralysis) and difficulty elevating the shoulder. Hence, (b) is correct.
3) Which of the following structures is deep to the sternocleidomastoid?
a) Internal jugular vein
b) External jugular vein
c) Platysma
d) Transverse cervical vein
Explanation:
The internal jugular vein lies deep to the sternocleidomastoid, while the external jugular vein runs superficially over it. This relationship is important during venipuncture and neck surgery. Answer: (a).
4) A patient with torticollis has which muscle affected?
a) Trapezius
b) Sternocleidomastoid
c) Platysma
d) Omohyoid
Explanation:
Congenital torticollis results from fibrosis or injury to the sternocleidomastoid, leading to tilting of the head toward the affected side and rotation to the opposite side. The primary involved muscle is sternocleidomastoid. Answer: (b).
5) Which artery crosses the sternocleidomastoid superficially?
a) Superior thyroid artery
b) Occipital artery
c) Transverse cervical artery
d) Suprascapular artery
Explanation:
The occipital artery, a branch of the external carotid artery, crosses the sternocleidomastoid superficially near its upper part before reaching the posterior scalp. This is an important surgical landmark. Answer: (b).
6) Clinical Case: A 35-year-old man develops neck stiffness and pain after whiplash injury. Which muscle is most likely strained?
a) Splenius capitis
b) Sternocleidomastoid
c) Trapezius
d) Levator scapulae
Explanation:
Whiplash injury causes overstretching of anterior neck muscles, mainly the sternocleidomastoid, due to rapid hyperextension and flexion. The patient presents with pain on head rotation and tenderness along the muscle belly. Hence, (b) is correct.
7) Clinical Case: A surgeon performing lymph node biopsy accidentally damages a nerve under the SCM. What symptom develops?
a) Difficulty swallowing
b) Shoulder droop
c) Loss of facial expression
d) Loss of tongue movement
Explanation:
The spinal accessory nerve runs deep to the sternocleidomastoid before supplying the trapezius. Injury causes shoulder droop due to trapezius weakness. Therefore, shoulder droop (b) occurs post-surgery.
8) Clinical Case: An infant presents with head tilted to one side since birth. Which is the most probable cause?
a) Fracture of clavicle
b) Injury to sternocleidomastoid during delivery
c) Facial nerve palsy
d) Atlantoaxial dislocation
Explanation:
Birth injury to the sternocleidomastoid causes fibrosis and shortening, leading to congenital torticollis with the head tilted toward the affected side. Hence, (b) is correct.
9) Clinical Case: A man complains of inability to rotate head to the left. Which side of SCM is paralyzed?
a) Left
b) Right
c) Both
d) None
Explanation:
Each sternocleidomastoid rotates the face to the opposite side. Therefore, inability to turn head to the left indicates right SCM paralysis. Hence, (b) is correct.
10) Clinical Case: Swelling beneath the sternocleidomastoid along the carotid sheath indicates infection in which space?
a) Retropharyngeal space
b) Parapharyngeal space
c) Pretracheal space
d) Carotid space
Explanation:
The carotid sheath lies deep to the sternocleidomastoid and contains the carotid artery, internal jugular vein, and vagus nerve. Infection in this space appears as swelling beneath the SCM. Hence, (d) is correct.