Head Practice Questions

Q: CSF Otorrhea is due to trauma of:

Petrous temporal bone. ***Petrous temporal bone*** - **CSF otorrhea** (leakage of cerebrospinal fluid from the ear) most commonly results from a fracture of the **petrous portion of the temporal bone**. - This bone forms part of the skull base and houses structures of the inner and middle ear, a fracture here can create a direct communication between the **subarachnoid space** and the external ear canal. *Tympanic membrane* - A rupture of the **tympanic membrane** alone would lead to **otorrhea** (ear discharge), but it would primarily involve blood or middle ear fluid, not CSF. - While a ruptured tympanic membrane is necessary for CSF to exit the ear canal, the source of the CSF leak itself is proximal to the middle ear. *Cribriform plate* - A fracture of the **cribriform plate** typically results in **CSF rhinorrhea** (CSF leakage from the nose), as it is located structurally above the nasal cavity. - It is not directly involved in CSF leakage from the ear. *Parietal bone* - Fractures of the **parietal bone** are typically associated with epidural or subdural hematomas or brain injury, depending on the extent of the trauma. - They are not a usual cause of CSF leakage from the ear since this bone does not contain CSF pathways that directly communicate with the ear.

Q: Which artery lies deep to the pterion?

Middle meningeal artery. ***Middle meningeal artery*** - The **pterion** is a weak area of the skull where four bones meet: the frontal, parietal, temporal, and sphenoid bones. The **middle meningeal artery** runs deep to this point. - A blow to the pterion can cause a rupture of the middle meningeal artery, leading to an **epidural hematoma**. *Temporal artery* - The **superficial temporal artery** is located more superficially, anterior to the ear, and is not deep to the pterion. - It is a branch of the **external carotid artery** and supplies the scalp. *Frontal artery* - The **frontal branch of the superficial temporal artery** supplies the forehead, but it does not run deep to the pterion. - The main frontal artery (part of the ophthalmic artery) is located within the orbit. *Parietal artery* - This term is non-specific; there isn't a single major artery referred to solely as the "parietal artery" in this context. - The **parietal branch of the superficial temporal artery** supplies the parietal region of the scalp but is superficial rather than deep to the pterion.

Q: Muscle in the lid attached to posterior tarsal margin is:

Muller's muscle. Muller's muscle - Also known as the **superior tarsal muscle**, it is a **smooth muscle** that originates from the underside of the levator palpebrae superioris and inserts directly onto the **superior tarsal plate (posterior tarsal margin)**. - Its sympathetic innervation helps maintain the **upper eyelid position** and contributes to eyelid elevation, with damage leading to **ptosis (Horner's syndrome)**. *Superior rectus* - This is an **extrinsic ocular muscle** responsible for **elevating the eyeball** and also contributes to adduction and intorsion [1]. - It does not insert on the tarsal margin but rather on the **sclera** of the eyeball. *Superior oblique* - This is another **extrinsic ocular muscle** primarily responsible for **intorsion** (medial rotation) of the eyeball and also contributes to depression and abduction [1]. - Its tendon passes through the **trochlea** and inserts on the **posterolateral superior aspect of the sclera**, not the eyelid. *Levator palpebrae superioris* - This **striated skeletal muscle** is the **primary elevator of the upper eyelid**, innervated by the oculomotor nerve (CN III). - While it is the main elevator, its fibrous aponeurosis inserts onto the anterior surface of the tarsal plate and the skin, and **Muller's muscle** arises from its undersurface and inserts directly into the posterior tarsal margin.

Q: The volume of the orbit is about:

30 cc. ***30 cc*** - The average **volume of the orbit** in adults is approximately **30 cubic centimeters (cc)** or 30 mL. - This volume accommodates the **eyeball** (approximately 7 cc), extraocular muscles, orbital fat, nerves (optic nerve), blood vessels, and lacrimal gland. - This is a standard anatomical measurement taught in medical education and used clinically for orbital imaging assessment. *40 cc* - This value **exceeds** the normal orbital volume by approximately 33%. - The actual orbital volume is closer to **30 cc**, not 40 cc. - This measurement does not represent the standard anatomical dimension. *50 cc* - This volume is significantly **larger** than the average orbital capacity. - It represents nearly **67% more** than the actual orbital volume. - This is not consistent with normal orbital anatomy. *60 cc* - This is **double** the actual average orbital volume. - Such a measurement far exceeds the normal anatomical dimensions of the human orbit. - The correct value is 30 cc, making this option clearly incorrect.

Q: Which of the following muscles causes the forward movement of the condyle in the mandibular fossa?

Lateral pterygoid. ***Lateral pterygoid*** - The **lateral pterygoid muscle** (especially its inferior head) is primarily responsible for **protrusion (forward movement)** of the mandible, causing the condyle to slide anteriorly along the articular eminence in the temporomandibular joint. - Its superior head stabilizes the **articular disc** during jaw movements, while the inferior head produces the forward translation. *Masseter* - The **masseter muscle** is a powerful muscle of mastication primarily involved in **elevation (closing)** of the mandible. - While it can assist slightly in protrusion when both sides contract, it does not produce the forward gliding movement of the condyle. *Medial pterygoid* - The **medial pterygoid muscle** primarily functions in **elevating** the mandible and assists in **protrusion** and grinding movements. - While it contributes to protrusion, the **lateral pterygoid** is the primary muscle responsible for the forward movement of the condyle. *Temporalis* - The **temporalis muscle** is a strong elevator of the mandible and its posterior fibers act as a **retractor**, pulling the mandible backward. - It opposes forward movement and is responsible for retrusion, not protrusion of the condyle.

Q: A skull is classified as dolichocephalic when the cephalic index is

Below 75. ***Below 75*** - A **cephalic index below 75** signifies a **dolichocephalic skull**, which is characterized by a relatively **long and narrow head**. - This classification is derived from the ratio of the maximum breadth to the maximum length of the skull (breadth/length × 100). - Dolichocephalic individuals have a **cranial index < 75**, indicating the skull is longer than it is wide. *75-80* - A cephalic index between 75 and 80 signifies a skull classification of **mesocephalic**, meaning a head of **medium breadth and length**. - This is considered the average or intermediate head shape. - This range represents the transition between dolichocephalic and brachycephalic skull types. *Above 80* - A cephalic index above 80 indicates a **brachycephalic skull**, characterized by a relatively **short and broad head**. - This is on the opposite end of the spectrum from dolichocephalic skulls. - Brachycephalic skulls are wider relative to their length. *None of the options* - This option is incorrect because one of the provided options correctly defines a dolichocephalic skull. - The cephalic index below 75 is the accepted criterion for dolichocephaly in anatomical classification.

Q: Frankfort horizontal is a reference plane constructed by joining which of the following landmarks?

Porion and Orbitale. Frankfort horizontal is a reference plane constructed by joining which of the following landmarks? ***Porion and Orbitale*** - The **Frankfort horizontal plane** is a standard anatomical reference plane used in craniometry and orthodontics. - It is constructed by connecting the **uppermost point of the external auditory meatus (porion)** with the **lowest point on the inferior margin of the bony orbit (orbitale)**. *Porion and Nasion* - The **nasion** is the point where the frontal and nasal bones meet, and its connection to the porion does not define the Frankfort horizontal plane. - This line would represent a different cranial orientation, not the internationally recognized Frankfort plane. *Porion and Sella* - The **sella** (sella turcica) is a saddle-shaped depression in the sphenoid bone housing the pituitary gland, which is an internal landmark. - Connecting the porion to the sella would create an internal reference line, not a surface-based horizontal plane typically used for facial analysis. *Nasion and Sella* - The line connecting the **nasion** and **sella** is known as the **Sella-Nasion line**, a common reference line in cephalometric analysis. - This line represents the anterior cranial base and is used to assess jaw relationships and growth patterns, separate from the Frankfort horizontal plane.

Q: Which nerve arises by two roots that surround the middle meningeal artery?

Auriculotemporal Nerve. ***Auriculotemporal Nerve*** - The **auriculotemporal nerve** typically arises from two roots that encircle the **middle meningeal artery**. - These two roots then unite to form a single trunk that continues superiorly. *Facial Nerve* - The **facial nerve (CN VII)** is a cranial nerve that emerges from the brainstem and exits the skull through the **stylomastoid foramen**. - It does not have roots that surround the middle meningeal artery. *Jacobson's Nerve* - **Jacobson's nerve** is the tympanic branch of the **glossopharyngeal nerve (CN IX)**. - It supplies sensory innervation to the middle ear and forms the **tympanic plexus**, not associating with the middle meningeal artery in this manner. *Maxillary Nerve* - The **maxillary nerve (CN V2)** is a branch of the trigeminal nerve and exits the skull through the **foramen rotundum**. - It does not involve roots surrounding the middle meningeal artery.

Q: Length of intraorbital part of the optic nerve is

25-30 mm. ***25-30 mm*** - The **intraorbital part** of the optic nerve is typically longer than the straight distance from the globe to the optic canal. - This extra length allows for **ocular movements** without stretching or damaging the nerve. *20-24 mm* - This range is **shorter** than the actual anatomical length of the intraorbital optic nerve. - An optic nerve of this length would be **taut** and vulnerable to damage during eye movements. *10-12 mm* - This measurement is significantly **too short** for the intraorbital segment. - It does not account for the **slack** needed for ocular motility. *35-40 mm* - This length is generally **too long** for the intraorbital portion of the optic nerve. - While some individual variation exists, this range falls outside the typical anatomical average.

Q: Which of the following extraocular muscles is not supplied by oculomotor nerve?

Lateral rectus. ***Lateral rectus*** - The **lateral rectus muscle** is innervated by the **abducens nerve (CN VI)**, not the oculomotor nerve (CN III). [1] - Its primary action is **abduction** of the eye, moving it laterally away from the midline. [1] *Inferior oblique* - The **inferior oblique muscle** is innervated by the **oculomotor nerve (CN III)**. [1] - Its actions include **extorsion**, elevation, and abduction of the eye. [1] *Medial rectus* - The **medial rectus muscle** is innervated by the **oculomotor nerve (CN III)**. [1] - Its primary action is **adduction** of the eye, moving it medially towards the midline. [1] *Inferior rectus* - The **inferior rectus muscle** is innervated by the **oculomotor nerve (CN III)**. [1] - Its actions include **depression**, extorsion, and adduction of the eye. [1]

Question 1

CSF Otorrhea is due to trauma of:

Accepted Answer

Petrous temporal bone

Answer

Tympanic membrane

Answer

Cribriform plate

Answer

Parietal bone

Question 2

Which artery lies deep to the pterion?

Accepted Answer

Middle meningeal artery

Answer

Temporal artery

Answer

Frontal artery

Answer

Parietal artery

Question 3

Muscle in the lid attached to posterior tarsal margin is:

Accepted Answer

Muller's muscle

Answer

Superior rectus

Answer

Superior oblique

Answer

Levator palpebrae superioris

Question 4

The volume of the orbit is about:

Accepted Answer

30 cc

Answer

40 cc

Answer

60 cc

Answer

50 cc

Question 5

Which of the following muscles causes the forward movement of the condyle in the mandibular fossa?

Accepted Answer

Lateral pterygoid

Answer

Masseter

Answer

Medial pterygoid

Answer

Temporalis

Question 6

A skull is classified as dolichocephalic when the cephalic index is

Accepted Answer

Below 75

Answer

75-80

Answer

Above 80

Answer

None of the options

Question 7

Frankfort horizontal is a reference plane constructed by joining which of the following landmarks?

Accepted Answer

Porion and Orbitale

Answer

Porion and Nasion

Answer

Porion and Sella

Answer

Nasion and Sella

Question 8

Which nerve arises by two roots that surround the middle meningeal artery?

Accepted Answer

Auriculotemporal Nerve

Answer

Facial Nerve

Answer

Jacobson's Nerve

Answer

Maxillary Nerve

Question 9

Length of intraorbital part of the optic nerve is

Accepted Answer

25-30 mm

Answer

20-24 mm

Answer

10-12 mm

Answer

35-40 mm

Question 10

Which of the following extraocular muscles is not supplied by oculomotor nerve?

Accepted Answer

Lateral rectus

Answer

Inferior oblique

Answer

Medial rectus

Answer

Inferior rectus

Head — MCQs

Head — MCQs

On this page

Practice by Chapter

Want unlimited practice?