cns 1st ch

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Which structure passes through the cribriform plate of the ethmoid bone besides the ethmoidal nerves and vessels?

Rootlets of the olfactory nerve (I).

The optic canal transmits the optic nerve (II) and which artery?

Ophthalmic artery.

Name the three cranial nerves that control eye movement and pass through the superior orbital fissure.

Oculomotor (III), trochlear (IV), and abducent (VI) nerves.

Which specific branches of the ophthalmic nerve ($V_{1}$) pass through the superior orbital fissure?

Lacrimal, frontal, and nasociliary nerves.

The superior orbital fissure transmits which venous structures?

Ophthalmic veins.

Which nerve is transmitted through the foramen rotundum?

Maxillary nerve ($V_{2}$).

Besides the maxillary nerve, what other structure passes through the foramen rotundum?

Middle meningeal vein.

The mandibular nerve ($V_{3}$) is transmitted through which skull foramen?

Foramen ovale.

"In the mnemonic 'ALE' for the foramen ovale, what does 'A' represent?"

Accessory meningeal artery.

"In the mnemonic 'ALE' for the foramen ovale, what does 'L' represent?"

Lesser superficial petrosal nerve.

"In the mnemonic 'ALE' for the foramen ovale, what does 'E' represent?"

Emissary vein.

Which artery is transmitted through the foramen spinosum?

Middle meningeal artery.

The nervus spinosus passes through which foramen in the skull?

Foramen spinosum.

Which nerve is found passing through the foramen lacerum?

Greater superficial petrosal nerve.

Which major artery is associated with the foramen lacerum?

Internal carotid artery.

The facial nerve (VII) and the vestibulo-cochlear nerve (VIII) both pass through which opening?

Internal auditory meatus.

Which artery accompanies the facial and vestibulo-cochlear nerves in the internal auditory meatus?

Internal auditory (labyrinthine) artery.

Name the three cranial nerves that exit the skull via the jugular foramen.

Glossopharyngeal (IX), vagus (X), and accessory (XI) nerves.

Which two venous sinuses pass through the jugular foramen?

Sigmoid and inferior petrosal sinuses.

The hypoglossal nerve (XII) passes through which specific opening in the skull?

Hypoglossal canal.

The foramen magnum marks the transition between the end of the medulla and the beginning of the _.

spinal cord

Which major paired arteries enter the skull through the foramen magnum?

Vertebral arteries.

Which nerve passes superiorly through the foramen magnum to enter the cranial cavity?

Spinal accessory nerve.

The apical ligament passes through which large skull opening?

Foramen magnum.

Which structure is transmitted through the foramen cecum?

Emissary vein.

The stylomastoid foramen transmits the facial nerve (VII) and the _ artery.

stylomastoid

Which nerves and vessels pass through the greater palatine canal?

Greater palatine nerve and vessels.

The internal carotid artery passes through which specific canal in the temporal bone?

Carotid canal.

How does the size of the cranium compare to the face in a neonatal skull?

The cranium is proportionately large while the face is small.

What is the bone structure characteristic of the neonatal skull regarding diploë?

It is smooth and unilaminar with no diploë.

At what age does the anterior fontanelle typically close?

18th month.

When does the posterior fontanelle typically close?

Between the 6th and 12th month.

What is the shape of the tympanic bone in a neonate?

Ring-shaped.

Which prominent feature of the adult temporal bone is absent in the neonatal skull?

Mastoid process.

What is the state of the neonatal mandible at the symphysis menti?

It is not united.

Describe the mandibular angle in a neonatal skull.

The angle is obtuse.

What are the two layers of the cranial dura mater?

Outer (endosteal) layer and inner (meningeal) layer.

The outer endosteal layer of the dura mater lines which structure?

The skull.

What is the primary function of the meningeal layer of the dura mater?

It covers the brain.

Where are the dural venous sinuses located in relation to the dural layers?

They are present between the two layers of the dura.

What characterizes the walls of dural venous sinuses regarding muscle tissue?

Their walls are devoid of muscular tissue.

Are dural venous sinuses valved or valveless?

Valveless.

Name the four dural folds formed by the inner layer of the dura mater.

Falx cerebri, tentorium cerebelli, falx cerebelli, and diaphragma sellae.

What is the shape and location of the falx cerebri?

It is sickle-shaped and located between the two cerebral hemispheres.

Where does the falx cerebri attach anteriorly?

Frontal crest and crista galli.

The posterior end of the falx cerebri attaches to the upper surface of which structure?

Tentorium cerebelli.

Which three dural sinuses are related to the falx cerebri?

Superior sagittal, inferior sagittal, and straight sinuses.

What is the function of the tentorium cerebelli?

It covers the cerebellum.

The free margin of the tentorium cerebelli forms the _, which surrounds the midbrain.

tentorial notch

To which three structures is the attached margin of the tentorium cerebelli fixed?

Posterior clinoid process, petrous bone, and transverse sulcus.

The tentorial notch is attached anteriorly to which bony process?

Anterior clinoid process.

Which four dural sinuses are related to the tentorium cerebelli?

Straight, transverse, superior petrosal, and inferior petrosal sinuses.

What is the shape and location of the falx cerebelli?

Small crescentic fold located between the two cerebellar hemispheres.

Where does the falx cerebelli attach?

Internal occipital crest.

Which sinus is related to the falx cerebelli?

Occipital sinus.

What is the function of the diaphragma sellae?

It covers the pituitary gland (hypophysis cerebri).

The diaphragma sellae is pierced by which structure?

Pituitary stalk (infundibulum).

Which sinuses are located in the margins of the diaphragma sellae?

Anterior and posterior inter-cavernous sinuses.

Which nerve pierces the dura at the point where the free and attached margins of the tentorium cerebelli cross?

Trochlear nerve (IV).

Where does the oculomotor nerve (III) pierce the dura in relation to the crossing of the tentorial margins?

In front of the crossing point.

Identify three examples of single (unpaired) dural venous sinuses.

Superior sagittal, inferior sagittal, straight, occipital, or inter-cavernous sinuses.

Identify three examples of paired dural venous sinuses.

Cavernous, transverse, sigmoid, superior petrosal, or inferior petrosal sinuses.

Where does the superior sagittal sinus begin?

At the apex of the falx cerebri above the crista galli.

The superior sagittal sinus usually continues as which sinus at the internal occipital protuberance?

Right transverse sinus.

What is the confluence of sinuses?

A dilatation at the internal occipital protuberance where several sinuses meet.

Where is the inferior sagittal sinus located?

Along the posterior half or two-thirds of the free margin of the falx cerebri.

The inferior sagittal sinus unites with the great cerebral vein to form which sinus?

Straight sinus.

The straight sinus is located at the junction of the falx cerebri and the _.

tentorium cerebelli

The straight sinus typically terminates by forming which sinus?

Left transverse sinus.

The sigmoid sinus is a direct continuation of which sinus?

Transverse sinus.

The sigmoid sinus ends by continuing as the _.

internal jugular vein

Through which compartment of the jugular foramen does the sigmoid sinus pass?

Posterior compartment.

"What is the 'circular sinus'?"

A venous circle formed by the cavernous and inter-cavernous sinuses around the hypophysis cerebri.

In which dural fold is the occipital sinus situated?

Attached margin of the falx cerebelli.

Where does the cavernous sinus extend from and to?

From the superior orbital fissure anteriorly to the apex of the petrous bone posteriorly.

What structures form the medial relation of the cavernous sinus?

Body of the sphenoid bone, sphenoidal air sinus, and pituitary gland.

Which part of the brain is located laterally to the cavernous sinus?

Uncus of the temporal lobe.

List the four nerves found in the lateral wall of the cavernous sinus from superior to inferior.

Oculomotor (III), trochlear (IV), ophthalmic ($V{1}$), and maxillary ($V{2}$) nerves.

Which two structures are located directly within the cavity of the cavernous sinus?

Abducent nerve (VI) and the internal carotid artery.

Name three venous tributaries of the cavernous sinus.

Superior ophthalmic vein, inferior ophthalmic vein, or central vein of the retina.

How does the cavernous sinus communicate with the facial vein?

Through the superior ophthalmic vein.

Through which foramina do emissary veins pass to connect the cavernous sinus with the pterygoid plexus?

Foramen ovale or foramen lacerum.

Where does the cavernous sinus drain via the superior petrosal sinus?

Transverse sinus.

Where does the cavernous sinus drain via the inferior petrosal sinus?

Internal jugular vein.

What clinical condition is defined by infection of the cavernous sinus?

Cavernous sinus thrombosis.

Why might cavernous sinus infection lead to eyeball edema?

Due to involvement of the ophthalmic veins.

What is ophthalmoplegia in the context of cavernous sinus pathology?

Paralysis of eye muscles due to complete compression of related cranial nerves.

Which clinical sign suggests an internal carotid artery affection within the cavernous sinus?

Pulsating exophthalmos.

Identify the site where the confluence of sinuses is located.

Internal occipital protuberance.

Which sinus is found on the clivus?

Basilar plexus of veins.

The spheno-parietal sinus is related to which bony landmark?

Lesser wing of the sphenoid.