p.2
Pia Mater Characteristics
How is the pia mater applied to the brain?
The pia mater is closely applied to the surface of the brain.
p.3
Arachnoid Mater and Subarachnoid Space
What separates the arachnoid mater from the dura mater?
A potential subdural space filled by a film of serous fluid.
p.3
Arachnoid Mater and Subarachnoid Space
What separates the arachnoid mater from the pia mater?
The subarachnoid space, which contains cerebrospinal fluid (CSF) and cerebral blood vessels.
What are the three meninges that surround the brain and spinal cord?
The pia mater, the arachnoid mater, and the dura mater.
p.2
Pia Mater Characteristics
Where does the pia mater dip into?
The pia mater dips into the sulci of the brain.
p.3
Arachnoid Mater and Subarachnoid Space
What is the arachnoid mater?
A delicate membrane covering the brain.
p.2
Pia Mater Characteristics
What is the pia mater?
The pia mater is the innermost covering of the brain.
p.6
Dural Folds and Their Functions
What are dural folds and how are they formed?
Dural folds are formed where the inner meningeal layer of the dura mater is folded.
p.7
Dura Mater Layers and Functions
Where does the transition of the dura mater layers occur?
At the margin of the foramen magnum.
p.3
Arachnoid Mater and Subarachnoid Space
Where is the arachnoid mater located?
Between the pia mater internally and the dura mater externally.
p.4
Arachnoid Mater and Subarachnoid Space
Why is the subarachnoid space dilated at certain sites?
To provide more protection or accommodate a big structure.
What is the function of the dural venous sinuses?
They are spaces where the two layers of the dura mater split to enclose venous blood.
p.8
Dural Folds and Their Functions
What are dural folds?
Duplications (two layers) from the inner layer of the dura, acting as septa separating different parts of the brain to stabilize them.
p.7
Dura Mater Layers and Functions
What happens to the outer periosteal layer of the dura mater at the margin of the foramen magnum?
It becomes continuous with the periosteum on the outer surface of the skull.
p.11
Dural Folds and Their Functions
Where is the Tentorium Cerebelli located?
It stretches horizontally across the posterior cranial fossa, separating the cerebrum above from the cerebellum below.
p.4
Arachnoid Mater and Subarachnoid Space
Which subarachnoid cistern is located near the corpus callosum?
Cistern of corpus callosum.
p.8
Dural Folds and Their Functions
What is the function of the falx cerebelli?
It acts as a septum separating different parts of the brain to stabilize them.
p.7
Dura Mater Layers and Functions
What happens to the inner meningeal layer of the dura mater at the margin of the foramen magnum?
It becomes continuous with the spinal dura mater.
p.10
Dural Folds and Their Functions
What is the characteristic of the upper border of the falx cerebri?
It is convex and attached to the sutural ligament of the sagittal suture.
p.11
Dural Folds and Their Functions
What is the Tentorium Cerebelli?
It is a reduplication of the inner layer of the dura mater.
p.10
Dural Folds and Their Functions
What is the characteristic of the lower border of the falx cerebri?
It is concave, free, and related to the corpus callosum.
p.4
Arachnoid Mater and Subarachnoid Space
Name an example of a subarachnoid cistern located between the cerebellum and medulla.
Cerebellomedullary cistern (cisterna magna).
p.9
Dural Folds and Their Functions
What is the Falx Cerebri?
It is a reduplication of the inner layer of the dura mater.
p.12
Dural Folds and Their Functions
Where is the free border of the tentorium cerebelli attached anteriorly?
To the anterior clinoid process.
p.8
Dural Folds and Their Functions
What is the function of the cavum trigeminale?
It acts as a septum separating different parts of the brain to stabilize them.
p.6
Dura Mater Layers and Functions
What are the two layers of the dura mater?
Outer periosteal layer and inner meningeal layer.
p.6
Dura Mater Layers and Functions
Where are the two layers of the dura mater firmly adherent?
They are firmly adherent except where they split to enclose the venous sinuses and where the inner layer is folded to form the dural folds.
p.7
Dura Mater Layers and Functions
What is the function of the inner meningeal layer of the dura mater?
It forms the spinal dura mater.
p.10
Dural Folds and Their Functions
Where is the apex of the falx cerebri attached?
To the frontal crest and crista gali.
p.8
Dural Folds and Their Functions
What is the function of the tentorium cerebelli?
It acts as a septum separating different parts of the brain to stabilize them.
Where is the inferior sagittal sinus located in relation to the falx cerebri?
In the posterior 2/3 of the lower border.
p.4
Arachnoid Mater and Subarachnoid Space
What increases in the subarachnoid cisterns?
The amount of cerebrospinal fluid (CSF).
p.7
Dura Mater Layers and Functions
What is the function of the outer periosteal layer of the dura mater?
It serves as the periosteum on the outer surface of the skull.
p.8
Dural Folds and Their Functions
Name the five dural folds.
Falx cerebri, Falx cerebelli, Tentorium cerebelli, Diaphragma sellae, Cavum trigeminale
p.12
Dural Folds and Their Functions
What is the function of the tentorial notch?
It surrounds the midbrain.
p.9
Dural Folds and Their Functions
Where is the Falx Cerebri located?
It occupies the median longitudinal fissure between the two cerebral hemispheres.
p.9
Dural Folds and Their Functions
What is the shape of the Falx Cerebri?
It is sickle-shaped, having an apex, base, two borders, and two surfaces.
Where is the superior sagittal sinus located in relation to the falx cerebri?
In the upper convex border.
p.18
Blood Supply and Nerve Supply of Dura Mater
Which artery is injured in an extradural hemorrhage due to a fracture in the region of the pterion?
Anterior division of the middle meningeal artery.
p.12
Dural Folds and Their Functions
What shape is the free border of the tentorium cerebelli?
U-shaped, surrounding the midbrain (tentorial notch).
What are dural venous sinuses?
Dilated venous channels between the inner and outer layers of the dura mater.
p.10
Dural Folds and Their Functions
Where is the base of the falx cerebri attached?
To the superior surface of the tentorium cerebelli.
What are the three sinuses related to the tentorium cerebelli?
Superior petrosal sinus, Transverse sinus, Straight sinus
p.15
Blood Supply and Nerve Supply of Dura Mater
What arteries supply the posterior cranial fossa of the dura mater?
Meningeal branches of occipital artery, vertebral artery, and ascending pharyngeal artery.
p.14
Dural Folds and Their Functions
What is the Cavum Trigeminale?
A reduplication of the inner layer of the dura mater that covers the trigeminal ganglion at the apex of the petrous part of the temporal bone.
What causes a subdural hemorrhage?
Tearing of the superior cerebral veins at their point of entrance into the superior sagittal sinus.
p.8
Dural Folds and Their Functions
What is the function of the diaphragma sellae?
It acts as a septum separating different parts of the brain to stabilize them.
p.12
Dural Folds and Their Functions
To which structures is the attached border of the tentorium cerebelli connected?
Posterior clinoid process, superior petrosal sulcus, and groove for transverse sinus.
Where is the straight sinus located in relation to the falx cerebri?
At the junction of the falx cerebri with the tentorium cerebelli.
p.16
Blood Supply and Nerve Supply of Dura Mater
Where does the middle meningeal artery lie within the dura mater?
Between the meningeal and endosteal layers of dura.
Do dural venous sinuses have muscular tissue?
No, they have no muscular tissue.
Where is the cavernous sinus located?
The cavernous sinus is located on either side of the sella turcica, a saddle-shaped depression in the sphenoid bone.
p.8
Dural Folds and Their Functions
What is the function of the falx cerebri?
It acts as a septum separating different parts of the brain to stabilize them.
p.15
Blood Supply and Nerve Supply of Dura Mater
Which nerves supply the middle cranial fossa of the dura mater?
Meningeal branches of maxillary nerve and mandibular nerve (trigeminal nerve).
p.17
Blood Supply and Nerve Supply of Dura Mater
In which direction does the posterior branch pass?
The posterior branch passes backward towards the lambda.
Can the origins of the transverse sinuses be reversed?
Yes, the reverse may occur.
Into what does the transverse sinus terminate?
It terminates as the sigmoid sinus.
p.35
Pia Mater Characteristics
What artery does the pia mater ensheathe?
The anterior spinal artery.
p.15
Blood Supply and Nerve Supply of Dura Mater
What arteries supply the middle cranial fossa of the dura mater?
Middle meningeal artery and accessory meningeal artery from maxillary artery.
What is the basilar plexus?
A network of veins located at the base of the skull.
What is the posterior extension of the cavernous sinus?
To the apex of the petrous part of the temporal bone.
Where is the superior sagittal sinus located?
In the upper convex border of falx cerebri.
Where does the superior sagittal sinus begin?
At foramen caecum opposite cresta galli.
What are the tributaries of the superior sagittal sinus?
Superior cerebral veins, emissary vein passing through the parietal foramen, and emissary vein passing through foramen caecum.
p.17
Blood Supply and Nerve Supply of Dura Mater
What area of the brain does the anterior branch correspond to?
The motor area of the brain.
Which sinuses are considered paired sinuses?
The sphenoparietal sinus, cavernous sinus, superior petrosal sinus, inferior petrosal sinus, transverse sinus, and sigmoid sinus are considered paired sinuses.
Which vein connects the superior sagittal sinus with the veins of the scalp?
The emissary vein passing through the parietal foramen.
p.16
Blood Supply and Nerve Supply of Dura Mater
Into which branches does the middle meningeal artery divide?
Anterior and posterior branches.
p.16
Blood Supply and Nerve Supply of Dura Mater
From which artery does the middle meningeal artery arise?
The 1st part of the maxillary artery in the infratemporal fossa.
p.14
Dural Folds and Their Functions
What is the Falx Cerebelli?
It is a reduplication of the inner layer of the dura mater between the two cerebellar hemispheres.
p.15
Blood Supply and Nerve Supply of Dura Mater
Which nerves supply the posterior cranial fossa of the dura mater?
Meningeal branch of vagus, meningeal branch of glossopharyngeal nerve, and first 3 cervical nerves.
p.18
Hydrocephalus and Its Causes
What are the potential symptoms of a hemorrhage in the brain?
Seizures, vomiting, and headache.
What is the function of the superior sagittal sinus?
It drains blood from the brain and the meninges.
Where is the straight sinus located?
In the posterior two-thirds of the lower border of falx cerebri.
Where does the superior sagittal sinus terminate?
It turns to the right and continues as the right transverse sinus.
Where does the sphenoparietal sinus terminate?
It opens into the anterior part of the cavernous sinus.
What does the cavernous sinus give at its posterior end?
Superior petrosal sinus and inferior petrosal sinus.
Where does the inferior petrosal sinus originate?
From the posterior end of the cavernous sinus.
How are dural venous sinuses connected to veins outside the cranial cavity?
By valveless emissary veins.
What is the anterior extension of the cavernous sinus?
From the medial end of the superior orbital fissure.
Where is the inferior sagittal sinus located?
At the junction of falx cerebri with tentorium cerebelli.
What is the role of the sigmoid sinus?
The sigmoid sinus drains blood from the transverse sinus to the internal jugular vein.
Where does the sphenoparietal sinus run?
Along the posterior free border of the lesser wing of the sphenoid.
How can an infection from the face lead to cavernous sinus thrombosis?
The infection can spread to the cavernous sinus, causing thrombosis.
Why can cavernous sinus thrombosis cause a squint?
Thrombosis can compress the nerves around the cavernous sinus, affecting eye movement and causing a squint.
What is the origin of the sigmoid sinus?
It is the direct continuation of the transverse sinus.
p.34
Arachnoid Mater and Subarachnoid Space
At what level does the spinal arachnoid mater end?
The level of the second sacral vertebra (S2).
p.36
Pia Mater Characteristics
What is the function of the denticulate ligaments?
They support the spinal cord.
p.37
Arachnoid Mater and Subarachnoid Space
Which veins are found in the subarachnoid space?
Corresponding spinal veins.
p.40
Brain Ventricles and Their Connections
What connects the 3rd and 4th ventricles?
The cerebral aqueduct of Sylvius.
p.44
Hydrocephalus and Its Causes
What is the definition of hydrocephalus?
An abnormal increase in the volume of the cerebrospinal fluid (CSF).
p.44
Hydrocephalus and Its Causes
What is another cause of hydrocephalus besides obstruction in circulation?
Thrombosis of the superior sagittal sinus.
p.41
Cerebrospinal Fluid (CSF) Composition and Functions
What are the main components of cerebrospinal fluid (CSF)?
Water (mainly), electrolytes, protein, lymphocytes, and glucose.
What is the function of the sphenoparietal sinus?
The sphenoparietal sinus drains blood from the brain and meninges into the cavernous sinus.
What is the function of the inferior petrosal sinus?
The inferior petrosal sinus drains blood from the cavernous sinus to the internal jugular vein.
Which vein connects the superior sagittal sinus with the veins of the nose?
The emissary vein passing through foramen caecum.
Where does the basilar plexus of sinuses lie?
Over the clivus of the skull.
What veins connect the cavernous sinus with the facial vein at its anterior end?
Ophthalmic veins (superior and inferior).
What vein does the cavernous sinus receive from above?
Superficial middle cerebral vein.
p.13
Dural Folds and Their Functions
What is the significance of the point of decussation between the free border and attached border of the tentorium cerebelli?
It determines the sites where the oculomotor, trochlear, and trigeminal nerves pierce the dura.
p.15
Blood Supply and Nerve Supply of Dura Mater
What blood vessels supply the anterior cranial fossa of the dura mater?
Anterior and posterior ethmoidal blood vessels (ICA).
p.15
Blood Supply and Nerve Supply of Dura Mater
Which nerve supplies the anterior cranial fossa of the dura mater?
Anterior ethmoidal nerve (trigeminal nerve).
p.17
Blood Supply and Nerve Supply of Dura Mater
Where does the anterior branch of the artery run?
The anterior branch runs up to the pterion, then passes upward and backward, corresponding to the motor area of the brain.
p.14
Dural Folds and Their Functions
What is the Diaphragma Sellae?
A reduplication of the inner layer of the dura mater that covers the pituitary gland.
Where is the inferior sagittal sinus located?
It is located in the lower margin of the falx cerebri.
Where is the cavernous sinus located?
At the sides of the body of the sphenoid.
p.27
Pituitary Gland Relations
What structures are located medially to the pituitary gland?
Pituitary gland and sphenoidal air sinus.
p.27
Pituitary Gland Relations
What structures are located superiorly to the pituitary gland?
Optic chiasma and internal carotid artery.
Where is the occipital sinus located?
In the attached margin of falx cerebelli.
Where does the superior petrosal sinus terminate?
At the junction of the transverse sinus and sigmoid sinus.
p.38
Dura Mater Layers and Functions
What are the components of the epidural space?
Loose fatty tissue and the internal vertebral venous plexus.
p.40
Brain Ventricles and Their Connections
Where are the lateral ventricles located?
In the brain hemispheres.
p.40
Brain Ventricles and Their Connections
What connects the lateral ventricles and the 3rd ventricle?
The interventricular foramen of Monro.
p.43
Cerebrospinal Fluid (CSF) Composition and Functions
What is one of the primary protective functions of cerebrospinal fluid (CSF)?
It acts as a shock absorber, cushioning the brain between the brain and cranium.
p.41
Cerebrospinal Fluid (CSF) Composition and Functions
What is the main source of cerebrospinal fluid (CSF) formation?
The choroid plexus of the lateral ventricle (70%) and less in the 3rd and 4th ventricles.
p.42
Cerebrospinal Fluid (CSF) Composition and Functions
Through which structures does the CSF drain into the dural venous sinuses?
Arachnoid villi and granulations.
p.18
Dura Mater Layers and Functions
What is the significance of the pterion in relation to skull fractures?
It is a region where a minor blow can cause a fracture leading to an extradural hemorrhage.
From where do dural venous sinuses receive tributaries?
The brain, diploic veins of the skull, the orbit, and the inner ear.
Where do dural venous sinuses finally drain blood?
Into the internal jugular vein.
What is the role of the superior petrosal sinus?
The superior petrosal sinus drains blood from the cavernous sinus to the transverse sinus.
p.27
Pituitary Gland Relations
What structures are located laterally to the pituitary gland?
Uncus of the temporal lobe of the brain and trigeminal ganglion (postero-inferior).
What structures are found in the floor of the cavernous sinus?
Internal carotid artery and sympathetic plexus around it, and the abducent nerve (6th) which lies inferolateral to the artery.
What is cavernous sinus thrombosis?
It is a condition where an infection from the face reaches the cavernous sinus, leading to its thrombosis.
What is proptosis and how is it related to cavernous sinus thrombosis?
Proptosis is the bulging of the eye, and it can be a manifestation of cavernous sinus thrombosis.
What is the role of the straight sinus?
It connects the inferior sagittal sinus to the confluence of sinuses.
What is the function of the intercavernous sinus?
It connects the cavernous sinuses on either side of the pituitary gland.
How does the inferior sagittal sinus terminate?
It usually turns to the left to form the left transverse sinus.
Where does the transverse sinus drain blood?
The transverse sinus drains blood from the confluence of sinuses to the sigmoid sinus.
p.27
Pituitary Gland Relations
What structures are located inferiorly to the pituitary gland?
Body of sphenoid and sphenoidal air sinus.
What are the manifestations of cavernous sinus thrombosis?
Black eye, squint, fever, and proptosis.
Where does the superior petrosal sinus originate?
From the posterior end of the cavernous sinus.
What connects both cavernous sinuses together medially?
Two intercavernous sinuses (anterior and posterior).
What is the origin of the left transverse sinus?
It is a continuation of the straight sinus.
Where may both transverse sinuses begin from?
From the confluence of the sinuses.
p.34
Dura Mater Layers and Functions
What is the spinal dura mater formed of?
A single layer (meningeal).
p.34
Arachnoid Mater and Subarachnoid Space
How does the spinal arachnoid mater compare to that of the brain?
It is more delicate than that of the brain.
p.36
Pia Mater Characteristics
From where to where do the denticulate ligaments extend?
From the foramen magnum to the first lumbar nerve (L1).
p.37
Arachnoid Mater and Subarachnoid Space
Where is the subarachnoid space located?
Between the arachnoid and pia mater.
p.37
Arachnoid Mater and Subarachnoid Space
Which arteries are found in the subarachnoid space?
Anterior and posterior spinal arteries.
p.39
Arachnoid Mater and Subarachnoid Space
Why is the lumbar cistern a perfect site for lumbar puncture?
Because it is filled with CSF and does not contain the spinal cord.
p.43
Cerebrospinal Fluid (CSF) Composition and Functions
How does cerebrospinal fluid (CSF) contribute to waste management in the brain?
CSF aids in the drainage of waste products from the brain.
How does the straight sinus terminate?
It ends by joining the great cerebral vein to form the straight sinus.
Name the single dural venous sinuses.
Superior sagittal sinus, Inferior sagittal sinus, Straight sinus, Occipital sinus, Basilar plexus, Intercavernous sinus.
Name the paired dural venous sinuses.
Sphenoparietal sinus, Cavernous sinus, Superior petrosal sinus, Inferior petrosal sinus, Transverse sinus, Sigmoid sinus.
What is the function of the intercavernous sinuses?
They connect the two cavernous sinuses on both sides.
What connects the cavernous sinus with the pharyngeal plexus of veins from below?
2-3 emissary veins through foramen lacerum.
Describe the shape and path of the sigmoid sinus.
It is an S-shaped sinus that runs in the sigmoid sulcus.
p.39
Arachnoid Mater and Subarachnoid Space
What is the lumbar cistern?
A sac of the subarachnoid space filled with CSF without the spinal cord.
p.43
Cerebrospinal Fluid (CSF) Composition and Functions
How does cerebrospinal fluid (CSF) help regulate the central nervous system (CNS)?
It regulates intracranial pressure and maintains the homeostatic environment of the CNS.
p.43
Cerebrospinal Fluid (CSF) Composition and Functions
By how much does cerebrospinal fluid (CSF) reduce the weight of the brain?
CSF reduces the weight of the brain 60 folds, from 1400 grams to 50 grams.
p.23
Arachnoid Mater and Subarachnoid Space
What is the function of the arachnoid villi and granulations in the superior sagittal sinus?
They project into the sinus through its wall to filter CSF into the venous stream.
What does the basilar plexus of sinuses connect?
The two inferior petrosal sinuses to each other.
What is the 'dangerous area of the face' in relation to cavernous sinus thrombosis?
It refers to the area of the face where infections can easily spread to the cavernous sinus, leading to thrombosis.
Where does the transverse sinus run?
Along the transverse sulcus.
How are the superior and inferior petrosal sinuses connected?
By the basilar venous plexus.
p.38
Arachnoid Mater and Subarachnoid Space
What is the subdural space?
A potential space between the dura and arachnoid.
p.38
Dura Mater Layers and Functions
What is the epidural space?
A space containing loose fatty tissue and the internal vertebral venous plexus.
p.40
Brain Ventricles and Their Connections
Where is the 4th ventricle located?
Between the pons, open medulla, and the cerebellum.
p.41
Cerebrospinal Fluid (CSF) Composition and Functions
What is the total volume of cerebrospinal fluid (CSF) in the body?
130 ml (30 ml in ventricles and 100 ml in subarachnoid space).
p.42
Brain Ventricles and Their Connections
After the fourth ventricle, where does the CSF flow?
Into the subarachnoid space of the brain and spinal cord.
Which dural venous sinus is especially involved in draining CSF?
The superior sagittal sinus (SSS).
List the structures found in the lateral wall of the cavernous sinus from above downwards.
Oculomotor nerve (3rd), trochlear nerve (4th), ophthalmic nerve (5th), maxillary nerve (5th).
Where does the superior petrosal sinus run?
Along the upper border of the petrous part of the temporal bone in the attached border of the tentorium cerebelli.
Where does the inferior petrosal sinus run?
Along the inferior petrosal sulcus.
What connects the cavernous sinus with the pterygoid venous plexus from below?
Emissary vein through foramen ovale.
Where does the inferior petrosal sinus terminate?
Passes through the jugular foramen and joins the internal jugular vein just below the skull.
What is unique about the termination of the inferior petrosal sinus?
It is the only sinus to end outside the skull.
What are the three meninges that surround the spinal cord?
Pia mater, arachnoid mater, and dura mater.
What is the origin of the right transverse sinus?
It is a continuation of the superior sagittal sinus.
p.34
Dura Mater Layers and Functions
With which layer is the spinal dura mater continuous?
The meningeal layer of the cranial dura.
p.34
Dura Mater Layers and Functions
At what level does the spinal dura mater end?
The level of the second sacral vertebra (S2).
p.35
Pia Mater Characteristics
Where does the pia mater enter after ensheathing the anterior spinal artery?
The anterior median fissure.
p.36
Pia Mater Characteristics
What are the two ligaments formed by the pia mater?
Filum terminale and denticulate ligaments.
p.36
Pia Mater Characteristics
How many serrated processes do the denticulate ligaments have?
21 serrated (tooth-like) processes.
p.39
Arachnoid Mater and Subarachnoid Space
Between which vertebral levels does the lumbar cistern extend?
From L2 to S2 vertebral levels.
p.39
Arachnoid Mater and Subarachnoid Space
What are the contents of the lumbar cistern?
CSF, cauda equina, and filum terminale.
p.41
Cerebrospinal Fluid (CSF) Composition and Functions
What is cerebrospinal fluid (CSF)?
It is the fluid that fills the ventricles of the brain and the subarachnoid space.
p.43
Cerebrospinal Fluid (CSF) Composition and Functions
What role does cerebrospinal fluid (CSF) play in nutritional exchange within the CNS?
CSF serves as a medium for nutritional exchange in the CNS.
p.41
Cerebrospinal Fluid (CSF) Composition and Functions
What are the other sources of cerebrospinal fluid (CSF) formation?
Ependymal and pia cells (30%).
p.42
Brain Ventricles and Their Connections
Where does the cerebrospinal fluid (CSF) circulation start?
In the lateral ventricles.
p.42
Brain Ventricles and Their Connections
What connects the third ventricle to the fourth ventricle?
The cerebral aqueduct of Sylvius.
p.42
Brain Ventricles and Their Connections
What is the Foramen of Magendie?
A median aperture in the fourth ventricle through which CSF flows into the subarachnoid space.
Where does the sigmoid sinus terminate?
It passes through the jugular foramen, where it continues with the internal jugular vein.
p.36
Pia Mater Characteristics
Where does the filum terminale extend from and to?
From the lower end of the conus medullaris to the back of the coccyx.
p.36
Pia Mater Characteristics
How do the denticulate ligaments extend?
They extend from the pia mater laterally, pierce the arachnoid, and attach to the dura mater.
p.38
Arachnoid Mater and Subarachnoid Space
What does the subdural space contain?
A very thin film of serous fluid.
p.42
Brain Ventricles and Their Connections
What is the Foramen of Monro also known as?
Interventricular foramen.
p.42
Brain Ventricles and Their Connections
What are the Foramina of Luschka?
Two lateral apertures in the fourth ventricle through which CSF flows into the subarachnoid space.
