Head and neck Flashcards
A young man is stabbed in the face, he sustains a jagged laceration extending from the mouth to the angle of the mandible. He presents to your ED with paralysis of muscles of the lower lip. Which nerve is most likely injured?
A Marginal mandibular branch
B Buccal mandibular branch
C Zygomatic mandibular branch
D Temporal mandibular branch
A
Explanation
Injury to the marginal mandibular branch of the CN VII may occur following an incision occurring along the inferior border of the mandible. This causes injury to the risoirus muscle, and muscles of the lower lip and chin (mentalis, depressor labii inferioris and depressor anguli oris)
The buccal branch of the facial nerve supplies the muscles of the upper lip (upper parts of the orbicularis oris and inferior fibres of levator labii superioris)
Note: in the prescribed textbook there is a table of the muscles of the scalp and face.
Muscles are mentioned and there corresponding nerve supply.
In this table the buccal branch of the CNVII supplies: procerus plus transverse part of nasalis, alar part of nasalis and levator labii superioris alaeque nasil, orbicularis oris, levator labii superioris, zygomaticus minor, buccinator, zygomaticus major, lavator anguli oris, RISORIUS.
The marginal mandibular branch supplies: depressor angularis oris, depressor labii inferioris and mentalis
A few pages later it describes the nerves in a paragraph and the muscles that it supplies.
The marginal mandibular branch- RISORIUS
Web search reports that the RISORIUS is supplied by the buccal branch.
Which is true regarding the development of the cranium?
A Eruption of permanent teeth is complete by year 15.
B The two halves of the mandible at birth fuse by the 5th year of life
C The sternocleidomastoid muscles help complete the development of the mastoid processes, which are absent at birth
D The bones of the calvaria and cranial base develop by intramembranous ossification only
C
Explanation
The bones of the calvaria and some parts of the cranial base develop by intramembranous ossification. Most parts of the cranial base develop by endochondral ossification. The facial aspect of the newborn is small compared to the calvaria (skull)-approximately one eighth of the cranium (because of the precocious growth and development of the brain and eyes). The adult facial skeleton forms one third of the cranium. There are no mastoid processes at birth, they form gradually during the first year of life as the sternocleidomastoid muscles complete their development and pull on the mastoid parts of the temporal bones. The mandible of the newborn consists of two halves of which the union begins in the first year and fusion occurs by the end of the second year. Eruption of permanent teeth is not complete until early adulthood. Growth of the face is associate with enlargement of the paranasal sinuses which adds to the final shape of the face and resonance to the voice
Which muscle controls vocal cord abduction in the larynx?
A Lateral cricoarytenoid
B Aryepiglottic
C Transverse arytenoid
D Posterior cricoarytenoid
D
Explanation
The posterior cricoarytenoid muscle is the most important muscle of the larynx as it is the only muscle that abducts the vocal folds and opens the glottis
Extra: The sole muscles responsible for abduction of the vocal cords are the posterior crico-arytenoid muscles. These muscles pull the muscular processes posteriorly, causing a lateral rotation of the vocal processes, resulting in the widening of the rima glottidis.
Which structures passes through the foramen spinosum
A Facial nerve
B Middle meningeal artery
C Internal carotid artery
D Mandibular branch of the trigeminal nerve
B
Explanation
The mandibular branch of the trigeminal nerve passes through the foramen ovale and the facial nerve passes through the internal acoustic maetus. Regarding the foracem lacerum, some sources say that the internal carotid artery emerges through a part of the foramen lacerum that is not occluded by cartilage. However, for the ACEM exams: the internal carotid artery and its accompanying sympathetic and venous plexuses actually pass horizontally acorss (rather than vertically through) the area of the foracem lacerum, an artifact of dry crania, which is closed by cartilage in life.
The Internal Carotid Arteries enter the cranial cavity through the carotid canal, in the petrous part of the temporal bone. The Facial Nerves emerge from the cranium through the stylomastoid foramen, located between the mastoid and styloid processes. The Mandibular Nerve (CN V3), is formed by the union of sensory fibres from the sensory ganglion on the motor root of CN V in the foramen ovale, in the greater wing of the sphenoid, through which CN V3 emerges from the cranium.
The meningeal branch of the mandibular nerve (CNV3) arises in the infratemporal fossa and returns to the cranial cavity via the foramen spinosum. The meningeal branch carries sensory fibers to innervate the dura mater in the posterior region of the middle cranial fossa.
The Middle Meningeal arteries, branches of the maxillary arteries, enter the floor of the middle cranial fossa through the foramen spinosum, run laterally in the fossa, and turn supero-anteriorly on the greater wing of the sphenoid, where it divides.
Which structure does not travel through the jugular foramen?
A Hypoglossal nerve
B Vagus nerve
C Accessory nerve
D Glossopharyngeal nerve
A
Explanation
The hypoglossal nerve passes through the hypoglossal canal.
Regarding the internal jugular vein, which of the following statements is correct?
A It runs from the angle of the jaw to the proximal end of the clavicle
B It runs in close proximity to the thoracic duct
C It runs deep to the two heads of sternocleidomastoid
D It lies medial to the carotid artery
C
Explanation
The IJV commences at the foramen in the posterior cranial fossa as the direct continuation of the sigmoid sinus. The vein descends in the carotid sheath accompanying the internal carotid artery superior to the to the carotid bifurcation and the common carotid artery and vagus nerve inferiorly. The vein lies laterally within the sheath, with the nerve located posteriorly. The thoracic duct crosses behind it on the left. The IJV leaves the anterior cervical region by passing deep to the SCM. The inferior end of the vein passes deep to the gap between the sternal and clavicular heads of this muscle. Posterior to the sternal end of the clavicle, the IJV merges with the subclavian vein to form the brachiocephalic vein
Older TB: In the lower part of sheath, the vessels are overlaid by the sloping SCM. The terminal part of the vein lies deep to the triangular interval between the sternal and triangular heads of the SCM.
In the new TB, it states that the thoracic duct ascends through the aortic hiatus in the diaphragm into the posterior mediastinum, where it collects more parietal and visceral drainage, particularly from the upper left quadrant of the body. The duct ultimately ends by entering the venous system at the junction of the left subclavian and internal jugular veins (the left venous angle)
The diagram shows the duct passing behind the IJV entering the venous system. It does not appear to run in close proximity- as per one of the stems
Regarding the gag reflex, which of the following statements is correct?
A Vagus nerve for efferent and afferent
B Maxillary nerve for afferent, vagus nerve for efferent
C Glossopharyngeal nerve for afferent, vagus nerve for efferent
D Hypoglossal nerve for afferent, vagus nerve for efferent
C
Explanation
The gag refles occurs when the palate, tonsil and posterior pharyngeal wall are touched by an unfamiliar object, as when testing with a swab. The passage of food over the same area does not cause the reflex, due to conditional familiarity. The afferent side of the reflex is via the glossopharyngeal nerve to the nucleus of the tractus solitarius, and the efferent side is via the vagus.
Which of the following structures is not involved in vocal cord movement?
A Posterior cricoarytenoid
B Aryepiglottics
C Vocalis
D Thyroarytenoid
B
Explanation
The aryepiglottics approximate the aryepiglottic folds and close the laryngeal inlet.
Although the aryepiglottic muscle is formed by same fibres form the oblique arytenoids-continuing form the arytenoid apex into the aryepiglottic fold, reaching the the edge of the epiglottis. They do not cause any action on the vocal cords. They act more like sphincters and closs the laryngeal inlet in the presence of liquids or particles
All other options below including transverse and oblique arytenoids, lateral cricoarytenois and cricothyroid muscles either stretch, relax, tense, abduct, adduct vocal ligaments and folds
After a tonsillectomy, a patient complains of loss of taste from the posterior tongue. Which nerve has been damaged?
A Hypoglossal
B Vagus
C Glossopharangeal
D Lingual
C
Explanation
The facial nerve is involved in the anterior taste of the tongue.
Note: - The facial nerve supplies the anterior 2/3 of the tongue via the chorda tympani (VII) - for special taste sensations.
The lingual nerve (V3) also supplies the anterior 2/3 of the tongue- for touch and temperature.
The lingual branch of glossopharyngeal nerve (IX) supplies the posterior 1/3 of the tongue- for both general and special taste sensations.
Vagus nerve ALSO supplies fibres to a small section of the posterior 1/3 of the tongue, via the internal laryngeal nerve (X)- for both general and special sense.
Which of the following bones makes up part of the roof of the orbit?
A Temporal
B Ethmoid
C Frontal
D Maxillary
C
Explanation
The orbital surface of the frontal bone is the true roof
Note: in the current texts it is noted that the superior wall of the orbit (roof) is formed mainly by the orbital part of the frontal bone. Near the apex of the orbit, the lesser wing of the sphenoid forms the superior wall.
Which of the following is a branch of the anterior division of the mandibular nerve?
A Zygomaticotemporal
B Lateral pterygoid
C Infraorbital
D Infratrochlear
B
Explanation
Anterior divison branches include the deep temporal branches, masseteric branches, lateral pterygoid and buccal. Posterior division branches include the auriculotemporal, inferior alveolar and lingual chorda tympani
Note the lingual chorda tympani is a branch of CN VII (facial) which branches within the facial canal of the temporal bone. The chorda tympani travels through the middle ear, posterior to anterior passing between incus and malleus. It enters infratemporal fossa and joins with fibres of CN V3, Mandibular nerve.
Which nerve is not contained within the carotid sheath?
A Vagus nerve
B Cervical sympathetic trunk
C Upper part of the hypoglossal nerve
D Upper part of the accessory nerve
B
Explanation
The four major structures contained in the carotid sheath are:
The common caoritd and internal carotid arteries
Internal jugular vein
Vagus nerve (CN X)
Deep cervical lymph nodes
Other structures: carotid sinus nerve and sympathetic nerve fibres (carotid periarterial plxuses)
The carotid artery lies medial to the internal jugular vein, and the vagus nerve is situated posteriorly between the two vessels.
In the upper part, the carotid sheath also contains the glossopharyngeal nerve (CNIX), the accessory nerve (CNXI, and the hypoglossal nerve (CNXII) which pierce the fascia of the carotid sheath.
The ansa cervicalis is embedded in the anterior wall of sheath. It is formed by “descendens hypoglossi” (C1) and “descendens cervicalis” (C2-C3).
Which of the following structures exits the skull through the stylomastoid foramen?
A Occipital artery
B Temporal artery
C Facial nerve
D Trigeminal nerve
C
Explanation
The stylomastoid foramen is the termination of the facial canal and transmits the facial nerve and stylomastoid artery.
The posterior triangle of the neck contains all of the following except?
A Cervical lymph nodes
B Superior belly of omohyoid
C Accessory nervy
D Cervical plexus
B
Explanation
The boundaries of the lateral cervical region/posterior triangle are: sternocleidomastoid, trapezius and clavicle.
The contents of the posterior triangle are:
Muscles: splenius capitus, levator scapulae, middle scalene, posterior scalene.
Arteries: lateral branches of the thyrocervical trunk, subclavian (3rd part), suprascapular artery, cervicodorsal trunk, superficial cervical artery, dorsal scapular artery.
Veins: external jugular vein, subclavian vein, (cervicodorsal vein, suprascapular vein and anterior jugular vein filter into the EJV)
Nerves: spinal accessory nerve, roots of the brachial plexus, suprascapular nerve, roots of the cervical plexus, superior and inferior root of the ansa cervicalis, cutaneous branches of the cervical plexus-lesser occipital, great auricular, transverse cervical and supraclavicular nerves. It also contains the phrenic, accessory phrenic nerves and deep motor branches of the cervical plexus
Lymph nodes: superficial and deep cervical lymph nodes
The superior belly of the omohyoid muscle is found in the anterior cervical region
Note: in older textbooks and web sources, the occipital nodes seem to lie in the posterior triangle. The number is small-2 to 3. Current texts do not reflect this.
The superior belly of the omohyoid muscle is found in the anterior cervical region
Which of the following is not a branch of the opthalmic nerve?
A Infratrochlear nerve
B Supratrochlear nerve
C Infraorbital nerve
D Supraorbital nerve
C
Explanation
The following are the branches of the ophthalmic nerve: lacrimal nerve, supraorbital nerve, supratrochlear nerve, infratrochlear nerve, and external nasal nerve (nasociliary). The new TB also includes a tentorial nerve (meningeal branch)
The new TB-divisions
Tentorial nerve (a meningeal branch)
Lacrimal nerve-Communicating branch form the zygomatic nerve
Frontal nerve-Supra-orbital nerve and supra-trochlear nerve
Nasociliary nerve- Sensory root of ciliary ganglion, Short ciliary nerves, Long ciliary nerves, Anterior and posterior ethmoidal nerves, Infra-trochlear nerve
Regarding cerebral veins which of the following statements is correct?
A They are thin walled and have valves
B The great cerebral vein drains into the cavernous sinus
C They do not follow the arterial pattern
D The veins lie subdurally
C
Explanation
The cerebral veins are thin walled and have no valves. They emerge in the brain and lie in the subarachnoid space. They pierce the arachnoid matter and the meningeal layer in the dura and drain into the cranial venous sinuses. The venous return does not follow the arterial pattern. Unlike the cortical arteries, which tend to travel deep in the sulci, the cortical veins tend to travel superficially; adherent to the deep surface of the arachnoid mater that bridges each sulcus.
The cavernous sinus, a large venous plexus, is located on each side of the sella tursica on the upper surface of the body of the sphenoid, which contains the sphenoid sinus. It receives blood form the superior and inferior ophthalmic veins, superior middle cerebral vein, and sphenoparietal sinus.
The great cerebral vein together with the inferior sagittal sinus forms the straight sinus, which joins the confluence of sinuses, which drains, into the transverse sinuses.
Which of the following opens into the inferior meatus of the nose?
A Nasolacrimal duct
B Frontal sinus
C Inferior alveolar nerve
D Ethmoidal sinus
A
Explanation
The nasolacrimal duct, 2cm long, slopes downwards, backwards, and laterally in conformity with the pear shaped nasal cavity, to open high up in the anterior part of the inferior meatus, 2cm behind the nostril
The contents of the posterior triangle of the neck include which of the following?
A Cervical plexus
B Superior belly of omohyoid muscle
C Occipital lymph nodes
D Second part of the subclavian artery
A
Explanation
The boundaries of the lateral cervical region/posterior triangle are: sternocleidomastoid, trapezius and clavicle.
The contents of the posterior triangle are:
Muscles: splenius capitus, levator scapulae, middle scalene, posterior scalene.
Arteries: lateral branches of the thyrocervical trunk, subclavian (3rd part), suprascapular artery, cervicodorsal trunk, superficial cervical artery, dorsal scapular artery.
Veins: external jugular vein, subclavian vein, (cervicodorsal vein, suprascapular vein and anterior jugular vein filter into the EJV)
Nerves: spinal accessory nerve, roots of the brachial plexus, suprascapular nerve, roots of the cervical plexus, superior and inferior root of the ansa cervicalis, cutaneous branches of the cervical plexus-lesser occipital, great auricular, transverse cervical and supraclavicular nerves. It also contains the phrenic, accessory phrenic nerves and deep motor branches of the cervical plexus
Lymph nodes: superficial and deep cervical lymph nodes
The superior belly of the omohyoid muscle is found in the anterior cervical region
Note: in older textbooks and web sources, the occipital nodes seem to lie in the posterior triangle. The number is small-2 to 3. Current texts do not reflect this.
Which of the following cranial nerves are not mixed nerves (both sensory and motor)
A CN VII
B CN X
C CN IX
D CN VI
D
Explanation
CN: V, VII, IX, X are mixed nerves with both somatic motor and somatic sensory components.
CN III, IV, VI, XI, XII and the motor root of CN V are considered to be pure motor nerves that appear to have evolved from primordial anterior roots
A “different” way to remember it: “Some Say Marry Money, But My Brother Says Big Bras Matter Most”
S= Sensory M= Motor B=Both/Mixed motor and sensory
Which of the following muscles controls vocal cord abduction in the larynx?
A Thyroarytenoid
B Cricothyroid
C Aryepiglottic
D Posterior cricoarytenoid
D
Explanation
The posterior cricoarytenoid muscle is the most important muscle of the larynx as it is the only muscle that abducts the vocal folds and opens the glottis.
Aryepiglottic- approximates the aryepiglottic folds and closes the laryngeal inlet
Cricothyroid- its contraction makes the thyorid tilt slightly dowwards and forwards, thereby lengthening and tensing the vocal ligament
Thyroarytenoid- shortens and relaxes the vocal ligament, altering the pitch of the voice
Cell bodies for the motor supply of the facial nerve lie in which of the following areas?
A Floor of third ventricle
B Pons
C Hypothalamus
D Midbrain
B
Explanation
The motor nucleus of the facial nerve is a brachiomotor nucleus in the venterolateral part of the pons, while the cell bodies of the primary sensory neurons are in the geniculate ganglion. The central processes involved in taste end in the nuclei of the solitary tract in the medulla. Processes concerned with general sensations (thermal, pain, touch) end in the spinal nucleus of the trigeminal ganglion.
Note: the rules of four: first 4 nerves in midbrain, next 4 in pons and last 4 in medulla.
The rule of 4 of the brainstem: a simplified method for understanding brainstem anatomy and brainstem vascular syndromes. It is available on the Web
The infratrochlear nerve supplies which of the following areas?
A Skin of the lower eyelid
B Bridge of the nose
C Upper incisors
D Labial portion of the gum
B
Explanation
The infratrochlear nerve passes forward on the medial wall of the orbit just below the trochlea, supplies the lacrimal sac and conjuctiva, and continues above the medial palpebral ligament to the skin of the upper eye lid and bridge of the nose
Current textbook: infratrochlear nerve supplies: skin lateral to root of nose, skin and conjunctiva of eyelids adjacent to medial canthus, lacrimal sac and lacrimal caruncle. External nasal nerve supplies: skin of nasal ala, vestibule and dorsum of nose including apex
Note: old question- I have not adjusted it- see it as a learning experience.
Corneal sensation pathway involves which ganglion?
A Trigeminal
B Ciliary
C Geniculate
D Optic
A
Explanation
The cornea is supplied by the short (mainly) and long ciliary nerves. To elicit the corneal reflex, touch the cornea (not the conjunctiva) with a wisp of cotton wool. A normal positive response is a blink (both eyes should shut). Absence of the response suggests a lesion of CN V1. A lesion of CN VII (the motor nerve to the orbicularis oculi) may also impair this reflex. The pathway is via the trigeminal ganglion to the main sensory nucleus, whence impulses pass by the way of the reticular formation to reach both facial nerve nuclei and so stimulate both orbicularis oculi to close the lids on both sides.
Extra: Corneal sensation is carried from the eye to the brain via the ophthalmic division of the trigeminal nerve. Fibres first travel to the ciliary ganglion via the short ciliary nerves.. These sensory fibres do not synapse in the ciliary ganglion (unlike the parasympathetic efferents controlling the sphincter pupillae and ciliary body). Instead they pass through it, and on to the trigeminal ganglion where their cell bodies lie. The fibres continue, now joined by sensory fibres from the maxillary and mandibular divisions, to enter the brain stem where they synapse with the mesencephalic, chief sensory, and spinal nuclei. As they are sensory somatic fibres, they do not synapse outside of the CNS.
The old question read: corneal sensation synapses in which ganglion?
All the following are branches of the external carotid except?
A Hypoglossal artery
B Ascending pharyngeal artery
C Lingual artery
D Facial artery
A
Explanation
Before the external carotid enters the parotid gland, it gives off six branches, three from in front, two from behind and one deep (medial). In front are the superior thyroid artery, lingual artery and facial artery. Behind are the occipital artery and the posterio-auricular artery. Medially is the ascending pharyngeal artery.
A nice mnemonic for the branches of the external carotid artery:
Some Anaesthetists Like Fun Others Prefer S and M
Superior Thyroid artery
Ascending pharyngeal artery
Lingual artery
Facial artery
Occipital artery
Posterior Auricular artery
Superficial temporal artery
Maxillary artery
To round out the explanation - the hypoglossal artery is a primitive artery not present in most adults. When present, it branches from the internal carotid and anastamoses with the basilar artery: https://radiopaedia.org/articles/persistent-hypoglossal-artery-2
While transversing the temporal bone within the facial canal, CN VII gives rise to following nerves except?
A Deep petrosal nerve
B Chorda tympani nerve
C Greater pertrosal nerve
D Nerve to the stapedius
A
Explanation
The facial nerve first gives off the greater petrosal nerve in the temporal bone. The deep petrosal nerve is the nerve that the greater petrosal nerve JOINS medially at the foramen lacerum, to form the nerve of the pterygoid canal. The deep petrosal nerve contains sympathetic fibres from the carotid plexus of the internal carotid artery.
Which of the following is a branch of the mandibular nerve?
A Auriculotemporal nerve
B Zygomaticofacial nerve
C Infraorbital nerve
D External nasal nerve
A
Explanation
The buccal, lingual nerve, inferior alveolar nerve, nerve to mylohyoid, inferior dental plexus and mental nerves are also branches of the mandibular nerve
The alar ligaments connect which of the following structures?
A Tips of adjacent spinous processes
B Adjacent vertebral bodies posteriorly
C Bodies of the axis to foramen magnum
D Dens to foramen magnum
D
Explanation
The alar ligaments extend from the sides of the dens to the lateral margins of the foramen magnum. The weak apical ligament joins the apex of the dens to the anterior margin of the foramen magnum and is a fibrous remnant of the notocord
All the following are boundaries of the named triangles with the exception of?
A Muscular and carotid triangles
B Muscular and digastric triangles
C Digastric and submental triangles
D Digastric and carotid triangles
B
Explanation
The submental triangle, inferior to the chin, is a suprahyoid area bounded inferiorly by the body of the hyoid and laterally by the right and left anterior bellies of the digastric muscles. the apex of the submental triangle is at the mandibular symphysis.
The mandibular triangle/digastric triangle boundaries include mandible, anterior and posterior bellies of digastric
The carotid triangle: sternocleidomastoid, posterior belly of digastric and superior belly of omohyoid
Muscular triangle: sternocleidomastoid, superior belly of omohyoid and midline from hyoid bone to jugular notch
Not a great question: The triangles need to share a common boundary. The muscular and digastric triangles do not share a common boundary.
The word boundary may not be the best term either as it means to separate, not share. I have left the question as is!
Which is true regarding subarachnoid cisterns?
A Pontocerebellar cistern is the largest cistern
B Ambient cistern contain parts of the great cerebral vein
C Ambient cistern is continous posteriorly with the quadrigeminal cistern
D Chiasmatic cistern is inferior and posterior to the optic chiasm
C
Explanation
Subarachnoid cisterns are openings in the subarachnoid space created by a separation of the arachnoid and pia mater. They contain CSF and soft tissue structures that anchor the brain. The cisterns are usually named according to the structures related to them.
Cerebellomedullary cistern-the largest of the cisterns located between the cerebellum and the medulla and receives CSF from the apertures of the 4th ventricle. It divides into a medial and lateral cerebellomedullary cistern.
Pontocerebellar cistern-an extensicve space ventral to the pons Interpeduncular cistern-located in the interpeduncular fossa
Chiasmatic cistern-inferior and anterior to the optic chiasm, the point of crossing of optic nerve fibres
Quadrigeminal cistern-contains parts of the great cerebral vein
Ambient cistern-located on the lateral aspect of the midbrain and is continuous posteriorly with the quadrageminal cistern.
Which zone of the neck is most commonly injured following a penetrating trauma?
A Zone Ia
B Zone III
C Zone I
D Zone II
D
Explanation
There are 3 zones of the neck. The zones give the doctors an understanding of the structures that are at risk with penetrating neck injuries.
Injuries to zones I and III- obstruct the airway; have the greatest risk of morbidity and mortality.
Zone II is the most common injured zone. Morbidity and mortality are lower because the doctor can control vascular damage with direct pressure and the structures can be visualised and treated more easily by the surgeons
Zone I- root of the neck, extends form clavicle and the manubrium to the level of the inferior border of the cricoid cartilage. Structures at risk include the cervical pleurae, lung apices, thyroid and parathyroid glands, trachea, oesophagus, common carotid artery, jugular veins and the cervical region of the vertebral column.
Zone II- extends form cricoid cartilage to the level of the angle of mandible. Structures at risk include superior pole of thyroid gland, thyroid and cricoid cartilage, larynx, laryngopharynx, carotid arteries, jugular veins, oesophagus and the cervical region of the vertebral column
Zone III- occurs at the angle of the mandible superiorly. Structures at risk include the salivary glands, oral and nasal cavities, oropharynx and nasopharynx.
A man is punched in the right orbital region. He complains of numbness to his right cheek. Which nerve has been affected?
A Facial
B Maxillary
C Ophthalmic
D Trochlear
B
Explanation
Cutaneous nerves derived from the maxillary nerve (CNV2)
Infrarorbital- mucosa of maxillary sinus. Premolar, canine and incisor maxillary teeth. Skin and conjunctiva of inferior eyelid. Skin of check, lateral nose and antero- infero nasal septum. Skin and oral mucosa of superior lip
Zygomaticofacial- skin on prominence of cheek
Zygomaticotemporal- hairless skin anterior part of temporal fossa
Regarding the ventricles of the brain, which is incorrect?
A CSF drains form the 4th ventricle via the foramen of Magendis and Luschka into the subarachnoid space
B The lateral ventricles consist of a body and anterior, posterior and inferior horns
C The choroid plexuses are not found in the 4th ventricle
D The cerebral aqueduct connects the third and fourth ventricles
C
Explanation
Cerebrospinal fluid is produced by the choroid plexuses found in the lateral, third and fourth ventricles. The lateral ventricles consist of a body and anterior, posterior and inferior horns and each ventricle drains into the 3rd ventricle through the interventricular foramina. The CSF drains into tthe 4th ventricle via the cerebral aqueduct. It then drains into the subarachnoid space via the median foramen (of Magendie) and the two lateral foramens (of Luschka).
Which is not a common branch of the basilar artery?
A Superior cerebellar
B Labyrinthine artery
C Anterior inferior cerebellar artery
D Pontine branches
B
Explanation
The basilar artery is formed by the intracranial parts of the vertebral arteries that unite at the caudal border of the pons. The basilar artery runs up infront of the pons. The basilar artery is so named because of its close relationship to the cranial base. It ends by dividing into the two posterior cerebral arteries. The labyrinthine artery is a long slender branch of the anterior inferior cerebellar artery (85%-100% cases) or basilar artery (<15% cases).
Features of the scalp include all except?
A The auriculotemporal and occipital nerves innervate the posterior part of the scalp
B Arterial supply is by the internal and external carotids
C There are no lymphnodes within the scalp
D The arteries and nerves run in the second layer of the scalp
A
Explanation
The scalp extends from the supraorbital margins anteriorly to the highest nuchal lines at the back of the skull and down to the ears and zygomatic arches at the sides. The composition of the scalp-it has five layers: SCALP= skin, connective tissue, aponeurosis with muscles at the front and back, loose areolar tissue and pericranium. Blood vessels and nerves run in the second layer (the dense connective tissue). The muscles of the scalp-the occipitalis and frontalis are supplied by posterior auricular branch and temporal branch respectively. The blood supply is derived from the external carotid artery by the occipital, posterior auricular and the superficial temporal branches, and from the internal carotid artery by the supratrochlear and supraorbial branches. All these arteries anastomose freely with each other. They are attached to the dense connective tissue of the second layer of the scalp and tend to be held open and bleed profusely when cut. There are no lymph nodes within the scalp. Drainage is via the occipital and posterior auricular nodes form the posterior scalp and the preauricular (parotid) nodes anteriorly. Nerve supply: posteriorly is the greater occipital nerve and third occipital nerves. Lesser occipital nerve supplies skin behind the ear. The temple by the auriculotemporal and the zygomaticotemporal nerves and the forehead by the supratrochlear and supraorbital nerves
Note: The muscles of the scalp-the occipitalis and frontalis are supplied by posterior auricular branch and temporal branch respectively
Regrading the anterior spinal artery, which is CORRECT?
A There are two anterior spinal arteries and one posterior spinal artery that supply the spinal cord
B It is uniform in size throughout the length of the spinal cord
C It is a branch of the vertebral or posterior inferior cerebral artery
D The artery supplies the anterior grey and white columns of both sides
D
Explanation
The spinal cord is supplied by the (single) anterior and (right and left) posterior spinal arteries that descend from the level of the foramen magnum and form three longitudinal channels form which branches enter the cord.
The ASA: Formed from the vertebral artery. It is larger than the posterior spinal arteries and runs the whole length of the spinal cord. It becomes very small in places like the thoracic cord that it appears absent. It supplies the whole cord anterior to the posterior grey columns and the anterior grey and white columns of both sides
The PSA: Formed from the posterior inferior cerebellar or vertebral artery. There is connection between the two arteries and some scanty connections with the ASA. The PSA supplies the grey and white posterior columns of its own side.
By themselves the ASA and the 2 PSAs can supply only the short superior part of the spinal cord. The circulation to most of the spinal cord depends on segmental medullary and radicular arteries running along the spinal roots. The anterior and posterior segmental medullary arteries are derived from spinal branches of the ascending cervical, deep cervical, vertebral, posterior intercostal and lumbar arteries.
The following is true about the submandibualr gland EXCEPT?
A It is larger than the sublingual gland
B Lymphatic drainage is chiefly via the jugulo-omohyoid node
C Parasympathetic secretomotor fibres is supplied by vagus
D The submental arteries supply the gland
C
Explanation
The submandibular glands lie along the body of the mandible, partly superior and inferior to the posterior part of the mandible, and partly superficial and partly deep to the mylohyoid muscle. The arterial supply is from the submental arteries. The veins accompany the arteries. The gland is supplied by presynaptic parasympathetic secretomotor fibres conveyed form the facial to the lingual nerve by the chorda tympani nerve, which synapse with postsynaptic neurons in the submandibular ganglion. Lymphatic drainage is via the deep cervical lymphnodes, particularly the jugulo-omohyoid node. The sublingual glands are the smallest salivary glands
Regarding the nasal cavity. Which is INCORRECT?
A Mucosa lines the entire nasal cavity
B Nerve supply of the nasal cavity is only V1 and V2 of the trigeminal nerve
C Lymphnode drainage of the nasal cavity is to the deep cervical, submandibular and retropharyngeal nodes
D 5 arteries supply the nasal cavity with blood
A
Explanation
The nasal cavity is entered anteriorly through the nares. It opens posteriorly into the nasopharynx through the choanae.
Mucosa lines the nasal cavity except for the nasal vestibule, which is lined with skin.
The nasal cavity is bound by a roof, floor, medial wall and a lateral wall
The nasal cavity is divided into 5 passages
Nerve innervation: Trigeminal nerve branches V1(ophthalmic) and V2 (maxillary).
The olfactory nerve-concerned with smell, arise form cells in the olfactory epithelium in the superior part of the lateral and septal wall of the nasal cavity. The nerve does not innervate the nasal cavity.
Vascular supply: Anterior ethmoidal artery (from the ophthalmic artery), posterior ethmoidal artery (from the ophthalmic artery), sphenopalatine artery (from the maxillary artery), greater palatine artery (from the maxillary artery), septal branch of the superior labial artery (from the facial artery)
Lymph drainage: submandibular, retropharyngeal and deep cervical nodes
Kiesselbach area is supplied by all of the following arteries EXCEPT?
A Septal branch of the inferior labial artery
B Sphenopalatine artery
C Anterior ethmoidal artery
D Greater palatine artery
A
Explanation
The anterior part of the nasal septum is called Kiesselbach’s area. It is an anastomosing arterial complex involving all 5 arteries supplying the septum. They include
Anterior ethmoidal artery from the opthalmic artery
Posterior ethmoidal artery from the opthalmic artery
Sphenopalatine artery from the maxillary artery
Greater palatine artery from the maxillary artery
Septal branch of the superior labial artery from the facial artery
Which autonomic cranial ganglion distribution paring is INCORRECT?
A Ciliary ganglion: iris
B Pterygopalatine ganglion: lacrimal gland
C Submandibular: sublingual
D Otic ganglion: eye muscles
D
Explanation
Ciliary ganglion:
parasympathetic (PS)-iris ; CN III
sympathetic (S)-dilator of pupil and blood vessels of the eye ; internal carotid plexus
Pterygopalatine ganglion:
PS-lacrimal gland ; CN VII
S-vessels of nasal cavity, palate, and superior parts of pharynx ; internal carotid plexus and CN V2
Otic ganglion:
PS- parotid gland ; CN IX
S-parotid gland blood vessels; superior cervical ganglion
Submandibular:
PS-sublingual and submandibular glands; CN VII
S-sublingual and submandibular glands ; superior cervical ganglion
Which ciliary ganglion-cranial nerve pairing is CORRECT?
A Submandibular ganglion: CN IX
B Otic ganglion: CN X
C Ciliary ganglion: CN II
D Pterygopalatine ganglion: CN VII
D
Explanation
Ciliary ganglion:
Parasympathetic root (PR)= CN III,
sympathetic root (SR)= internal carotid plexus
Pterygopalatine ganglion:
PR= CN VII,
SR= internal carotid plexus and CNV2
Otic ganglion:
PR= CN IX,
SR= superior cervical ganglion
Submandibular ganglion:
PR= CN VII,
SR= superior cervical ganglion
Note: for cranial nerve contributions to the ganglion of the head and neck: COPS 3977 (i.e. ciliary CN III, otic CN IX, pterygopalatine CN VII, and submandibular CN VII)
If a herniation of a cervical disc occurs at the C5-C6 level, in what region would the pain most likely be refered?
A Shoulder
B Lateral arm
C Fingers
D Thumb
D
Explanation
The cervical spine nerves exit superior to the vertebra of the same number, so the numerical relationship of herniating disc to nerve affected is the same as the lower verterbra. If a disc is ruptured at C5-C6 level, the C6 spinal nerve will be compressed. If there is a C6-C7, the C7 spinal nerve will be compressed. The same does not hold below the cervical spine as the nerves exit inferior to the vertebrae.
C6- covers the lateral forearm (below elbow) and the thumb.
Extra:
Perhaps another way to explain why the numerical relationship is the same despite the above/below root exit is different. My understanding from the current books is that e.g. C4/5 affects C5 and L4/5 affects L5. The reason being that even though the nerve roots exit above in the C spine and below in the T and L spine, there are anatomical differences in the IV foramina between the regions. In the T and L spine, the foramina are partly bound by bone superiorly and disc inferiorly, and the nerve exits at the bony portion of the foramina, so a bulging disc at a given level can’t contact that nerve, and so compresses the nerve exiting at the next level. Whereas in the C spine the disc is more central (in a vertical sense) in the foramina, so a nerve exiting at that level must be contacted by the disc (it is not exiting along bone as with the lower segments) Therefore the numerical association ends up being the same, but for different anatomical reasons
Which of the following arteries are NOT DIRECTLY involved in causing an anterior nose bleed?
A Septal branch of the superior labial artery
B Anterior ethmoidal artery
C Sphenopalatine artery
D Maxillary artery
D
Explanation
The anterior part of the nasal septum is the site (Kiesselbach area) of an anastomotic arterial plexus involving 5 arteries
Anterior ethmoidal artery (from the ophthalmic artery)
Posterior ethmoidal artery (from the ophthalmic artery)
Sphenopalatine artery (from the maxillary artery)
Greater palatine artery (from the maxillary artery)
Septal branch of the superior labial artery (from the facial artery)
Which of the following nerves is NOT a cutaneous branch of the ophthalmic division of the trigeminal nerve CNV supplying the face and scull
A Supratrochlear
B Lacrimal
C Zygomaticotemporal
D External nasal
C
Explanation
CNV- Ophthalmic division cutaneous branches:
Supraorbital
Supratrochlear
Lacrimal
Infratrochlear
External nasal
CNV- Maxillary division-cutaneous branches:
Zygomaticotemporal
Infra-orbital
Zygomaticofacial
CNV- Mandibular division -cutaneous branches:
Auriculotemporal
Mental
Buccal
Which of the following eye muscles depresses, adducts and laterally rotates the eyeball?
A Superior oblique
B Inferior oblique
C Inferior rectus
D Superior rectus
C
Explanation
Superior oblique: Abducts, depresses and medially rotates the eyeball
Inferior oblique: Abducts, elevates and laterally rotates the eyeball
Superior rectus: Adducts, elevate and medially rotates the eyeball
Inferior rectus: Adducts, depress and laterally rotates the eyeball
Which of the following branches of the external carotid artery do not arise in the carotid triangle?
A Occipital artery
B Lingual artery
C Posterior auricular artery
D Ascending pharyngeal artery
C
Explanation
Arising in the carotid triangle:
Superior thyroid artery
Ascending pharyngeal artery
Lingual artery
Facial artery
Occipital artery
Separate to the carotid sheath
Posterior auricular artery does not arise in the carotid triangle
Terminal branches:
Maxillary artery
Superficial temporal artery
The anterior triangle of the neck is divided into 4 smaller triangles. Which of the following smaller triangles is INCORRECT?
A Carotid triangle
B Digastric triangle
C Hyoglossus triangle
D Muscular triangle
C
Explanation
The anterior triangle (anterior cervical region) boundaries:
Sternocleidomastoid,
Mandible
Midline
The triangle is subdivided into 4 smaller triangles:
Carotid
Digastric (aka submandibular)
Submental
Muscular
Below are the contents of the first three triangles:
Muscles:
Suprahyoid muscles
Mylohyoid, genihyoid, stylohyoid, digastric
Infrahyoid muscles
Sternohyoid, sternothyroid, thyrohyoid, omohyoid
Arteries:
Carotid system of arteries
CC, IC, EC
Submandibualr branches
Submental vessels
Mylohyoid vessels
External carotid branches
Ascending pharyngeal
Occipital
Posterior auricular (not included)
Superior thyroid
Lingual
Facial
Veins:
Tributaries of the IJV
Nerves:
Transverse cervical
Hypoglossal
Branches of the glossopharyngeal
Branches of the vagus nerve
Laryngeal nerve
Mylohoid nerve
Ansa cervacalis
Lymph nodes:
Jugulo digastric
Glands:
Submandibular
Muscular triangle contents: parts of larynx, trachea, pharynx, oesophagus, thyroid and parathyroid glands-their vessels, nerves and glands
The infra-orbital nerve innervates all of the following parts of the face EXCEPT?
A Conjunctiva of the inferior eye lid.
B Skin of the oral mucosa of superior lip
C Mucosa of incisor maxillary teeth
D Dorsum and apex of the nose
D
Explanation
The infra-orbital nerve innervates the mucosa of the maxillary sinus. Mucosa of the premolar, canine and incisor maxillary teeth. Skin and conjunctiva of the inferior eye lid. Skin of the cheek, lateral nose and anteroinferior nasal septum. Skin of the oral mucosa of superior lip.
The alae of the nose are supplied by the nasal branches of the infraorbital nerve V2
The dorsum and apex of the nose is supplied by the CN V1 (via the infratrochlear nerve and the external nasal branch of the anterior ethmoidal nerve). The anterior superior portion is also supplied by the CN V1 (ophthalmic) via the anterior and posterior ethmoidal nerves.
Note: Innervation of the teeth: by the superior alveolar nerves form the maxillary nerve (V2). The lower teeth by the inferior alveolar branch of the mandibular nerve (V3)
Which fascia encloses the retropharyngeal space anteriorly?
A Investing fascia
B Alar fascia
C Deep cervical fascia
D Buccopharyngeal fascia
D
Explanation
The retropharyngeal space (RPS) is the largest and most important interfacial space in the neck. This potential space consists of loose connective tissue between the visceral part of the prevertebral layer of the deep cervical fascia and the buccopharyngeal fascia (pre-tracheal layer) surrounding the pharynx superficially. The alar fascia forms a further subdivision of the retropharyngeal space. The RPS permits movement of the pharynx, oesophagus, larynx and trachea relative to the vertebral column during swallowing. The space s closed superiorly by the cranial base and on each side by the carotid sheath. It opens inferiorly into the superior mediastinum.
Which of the following cranial foramina and contents is INCORRECT?
A Foramen rotundum = Ophthalmic nerve (CN V1)
B Jugular foramen = CN X
C Foramen spinosum = Middle meningeal artery
D Foramen ovale = Mandibular nerve (CN V3)
A
Explanation
This question was created to ensure you review all the cranial foramina and their contents. An EMQ is easily created. Note the bones of the cranium which create the foramina as well.
Foramen rotundum = Maxillary nerve (CNV2)
Which of the following cranial nerves (Cn) has its nucleus outside the brainstem?
A CN XI
B CN X
C CN VII
D CN V
A
Explanation
CN I and II = Forebrain
CN III, IV = Midbrain
CN V, VI, VII, VIII, IX, X, XII = Brainstem
CN XI = Superior spinal cord
Which nerve supplies the pinna of the ear?
A Maxillary nerve
B Mandibular nerve
C Vagus nerve
D Facial nerve
B
Explanation
The auricle is the visible part of the ear that resides outside the head. Also called the pinna
The main nerves to the skin of the auricle are great auricular and auriculotemporal nerves. The great auricular nerve (originating from the cervical plexus-composed of nerves form C2 and C3) supplies the cranial (medial) surface-commonly the back of the ear-and the posterior part (helix, antihelix and lobule) of the lateral surface (front). The auriculotemporal nerve, a branch of V3, supplies the skin of the auricle anterior to the acoustic meatus.
I think the majority of the ear is innervated by the great auricular nerve, but the options given only allow the mandibular (V3) nerve and its branch the auriculotemporal nerve.
Extra:
The mandibular nerve (CN V3) is the inferior and largest division of the trigeminal nerve. It is formed by the union of sensory fibers from the sensory ganglion and the motor root of CN V in the foramen ovale in the greater wing of the sphenoid, through which CN V3 emerges from the cranium. CN V3 has three sensory branches that supply the area of skin derived from the embryonic mandibular prominence. It also supplies motor fibers to the muscles of mastication. CN V3 is the only division of CN V that carries motor fibers. The major cutaneous branches of CN V3 are the auriculotemporal, buccal, and mental nerves. En route to the skin, the auriculotemporal nerve passes deep to the parotid gland, conveying secretomotor fibers to it from a ganglion associated with this division of CN V.
A 65-year-old woman suffers a CVA and presents with right-sided hemiparesis. Where is the lesion?
A Posterior cerebral artery
B Posterior communicating artery
C ACA
D MCA
D
Explanation
ACA strokes typically present with weakness predominately affecting the leg/foot of the opposite side, due to involvement of the leg part of the motor cortex.
MCA involvement more typically gives a hemiparesis/hemisensory loss picture on the contralateral side.
An 18-year-old male presents to the emergency department after being punched in the right eye. He complains of numbness to his right cheek. A branch of which nerve is likely damaged?
A Vagus
B Facial
C Mandibular
D Maxillary
D
Explanation
The infra-orbital nerve is a branch of the maxillary division of the trigeminal nerve.
A 24-year-old man has been punched to the upper lip and requires repair of a lip laceration in the emergency department. Blockade of which nerve will provide appropriate sensory anaesthesia?
A Mandibular
B Buccal
C Infra-orbital
D Intra-trochlear
C
Explanation
The infra-orbital nerve, a branch of CNV2, gives sensory supply to the inferior eyelid, lateral nose/cheek, mucosa of the maxillary sinus, upper medial teeth, and skin and oral mucosa of the upper lip.
A rugby player requires repair of a laceration to his pinna in the emergency department. Blockade of which nerve will provide appropriate sensory anaesthesia?
A Mandibular
B Facial
C Maxillary
D Vagus
A
Explanation
Branch of the mandibular nerve supplies sensation to the pinna of the ear.
As per earlier an earlier explanation- two nerves supply the pinna of the ear.
Auriculotemporal nerve, a branch of the mandibular (V3) nerve.
The great auricular nerve originates from the cervical plexus, composed of branches of spinal nerves C2 and C3.
Extra
Motor innervation to muscles of the external ear is supplied by branches of the facial nerve (CN VII)
Which nerve passes through the jugular foramen?
A CN XII
B CN IX
C CN V
D CN VII
B
Explanation
Structures passing through the jugular foramen include CN IX, X, XI; inferior petrosal and sigmoid sinuses; ascending pharyngeal and occipital arteries.
The straight sinus is formed by:
A Super sagittal sinus and great cerebral veins
B Super sagittal sinus and inferior sagittal sinus
C Inferior sagittal sinus and great cerebral veins
D Superior sagittal sinus and great vertebral veins
C
Explanation
The inferior sagittal sinus and greater cerebral veins form the straight sinus, which meets the superior sagittal sinus at the confluence of sinuses and drains into the transverse sinuses bilaterally.
Which cell is responsible for myelin formation in the CNS?
A Dendrites
B Astrocytes
C Oligodendrocytes
D Schwann cells
C
Explanation
Schwann cells make myelin in the peripheral nervous system (PNS: nerves) and oligodendrocytes in the central nervous system (CNS: brain and spinal cord).
The primary motor centre is found in which lobe?
A Occipital
B Temporal
C Parietal
D Frontal
D
Explanation
The primary motor cortex (M1) is in the precentral gyrus of the frontal lobe, extending into the central sulcus. The primary somatosensory cortex is in the postcentral gyrus of the parietal lobe.
A gentleman presents with shingles across his right cheek, which nerve in likely involved?
A Infraorbital
B Supraorbital
C Buccal
D Zygomatic
A
Explanation
The infra-orbital nerve (derived from maxillary nerve V2) supplies the mucosa of maxillary sinus, pre-molar canine, incisor of maxillary teeth, skin and conjunctiva of inferior eyelid, skin of cheek, lateral nose, and antero-inferior nasal septum, skin and oral mucosa of superior lip
A patient sustains a laceration to the inferior mandible. Which nerve is most likely to be affected?
A Zygomatic nerve
B Marginal mandibular nerve
C Buccal nerve
D Cervical nerve
B
Explanation
The marginal mandibular branch of CN VII supplies the risorius and muscles of the lower lip and chin. It emerges from the inferior border of the parotid gland and crosses the inferior border of the mandible deep to the platysma to reach the face. In approximately 20% of people, this branch passes inferior to the angle of the mandible.
The cervical branch of CN VII passes inferiorly from the inferior border of the parotid gland and runs posterior to the mandible to supply the platysma. Looking at the picture showing the distribution of terminal branches of CN VII, the cervical branch appears to innervate more of the neck than the area over the mandible
What is the afferent pathway for the sneeze reflex?
A Glossopharyngeal
B Vagus
C Maxillary nerve
D Mandibular
C
Explanation
Pathophysiology
The sneezing reflex may be divided into two phases. The first is a nasal or sensitive phase, following stimulation of the nasal mucosa by chemical or physical irritants. Many distal branches of trigeminal nerve terminate in the facial skin transmitting tactile, pain and temperature sensations, while some branches distribute in the nasal mucosal epithelium [Nishino, 2000]. These branches are myelinated sensory fibres of small diameter, which terminate with receptor endings. Some of these receptors are triggered by chemical stimuli while others are sensitive to tactile and mechanical stimuli [Nishino, 2000]. Afferent neural stimuli are transmitted to the trigeminal ganglion via anterior ethmoidal, posterior nasal, infraorbital and ophthalmic branches of the trigeminal nerve. Through the trigeminal ganglion the stimuli reach the sneezing centre in the lateral medulla.
It seems that both V1 abd V2 are involved in sneezing. but, V1-Opthalmic nerve is not given as an option. Therefore V2-Maxilary nerve is the next best.
Source: https://journals.sagepub.com/doi/pdf/10.1177/1753465809340571
