Meninges and Intracranial Venous Sinuses Flashcards
What are the three meningeal layers that cover and protect the brain and spinal cord?
Pia mater (innermost layer)
Arachnoid mater (middle layer)
Dura mater (outermost layer)
What is the function of the arachnoid villi and arachnoid granulations?
Arachnoid villi and granulations filter cerebrospinal fluid (CSF) into the intracranial venous sinuses, allowing CSF to re-enter the bloodstream.
What is the subarachnoid space, and what does it contain?
The subarachnoid space is the area between the pia mater and arachnoid mater. It contains cerebrospinal fluid (CSF), arachnoid trabeculae, cerebral and spinal vessels, and cranial and spinal nerve roots.
What are the denticulate ligaments, and what is their function?
Denticulate ligaments are 21 paired lateral extensions of the pia mater that anchor the spinal cord to the dura mater, providing stability along the length of the spinal cord.
What is the filum terminale, and where does it end?
The filum terminale is a thin extension of the pia mater that extends inferiorly from the conus medullaris in the subarachnoid space. It pierces the dura mater at the S2 vertebral level and ends at the coccyx.
What are the meningeal spaces, and what are their names?
Subarachnoid space (between pia and arachnoid)
Subdural space (potential space between dura and arachnoid)
Epidural/Extradural space (outside the dura)
Where is the Superior sagittal sinus located
The superior sagittal sinus is an intracranial venous sinus that runs along the attached margin of the falx cerebri. It is located between the endosteal and meningeal layers of the dura mater.
What is the cavernous sinus, and what structures does it contain?
Internal carotid artery (cavernous portion)
Cranial nerves: III (oculomotor), IV (trochlear), VI (abducens), V1 (ophthalmic), and V2 (maxillary)
Veins: Superior and inferior ophthalmic veins, superficial middle cerebral vein, and others.
What is the confluence of sinuses, and which sinuses meet there?
Superior sagittal sinus
Straight sinus
Occipital sinus
Two transverse sinuses
What is cavernous sinus thrombosis, and what are its symptoms?
Cavernous sinus thrombosis is a condition where the cavernous sinus becomes blocked by a blood clot. Symptoms include:
Severe headache
Swelling, redness, or irritation around the eyes
Drooping eyelids
Inability to move the eye
Fever
Vision loss or double vision
What is the lumbar cistern, and what does it contain?
The lumbar cistern is an enlarged portion of the subarachnoid space located at the lower part of the spinal canal, beyond the conus medullaris. It contains the filum terminale and the cauda equina.
What is the tentorium cerebelli, and what is its function?
The tentorium cerebelli is a fold of the dura mater that forms a roof over the cerebellum. It separates the cerebellum from the occipital lobes of the cerebrum.
What is the falx cerebri, and what does it separate?
The falx cerebri is a fold of the dura mater that separates the two cerebral hemispheres of the brain.
What is the diaphragma sellae, and what does it cover?
The diaphragma sellae is a fold of the dura mater that forms a roof over the pituitary gland in the sella turcica.
What is the inferior sagittal sinus, and where is it located?
The inferior sagittal sinus is an intracranial venous sinus that runs in the inferior free margin of the falx cerebri. It drains into the straight sinus.
What is the straight sinus, and what are its tributaries?
The straight sinus is located between the posterior end of the falx cerebri and the middle of the tentorium cerebelli. Its tributaries include:
Inferior sagittal sinus
Great cerebral vein of Galen
Posterior cerebral veins
Superior cerebellar veins
What is the sigmoid sinus, and where does it drain?
The sigmoid sinus is a continuation of the transverse sinus. It drains into the internal jugular vein via the jugular foramen.
What is the epidural space, and what does it contain in the spinal region?
The epidural space is located between the vertebrae and the dura mater. In the spinal region, it contains spinal nerve roots, adipose tissue, and epidural vessels.
What is the danger area of the face, and why is it significant?
The danger area of the face refers to the region where infections can spread to the cavernous sinus via the facial veins. This can lead to serious complications like cavernous sinus thrombosis.
What is the lumbar puncture, and where is it performed?
A lumbar puncture is a medical procedure where a needle is inserted into the lumbar cistern (in the lower part of the subarachnoid space) to collect cerebrospinal fluid (CSF) for diagnostic or therapeutic purposes.
What are meningiomas, and what symptoms can they cause?
Meningiomas are tumors that arise from the arachnoid layer of the meninges. They can compress parts of the brain, spinal cord, or nerves, leading to symptoms like paralysis or sensory deficits.
What is the difference between extradural, subdural, and subarachnoid hemorrhage?
Extradural hemorrhage: Bleeding between the skull and dura mater, often due to trauma.
Subdural hemorrhage: Bleeding between the dura mater and arachnoid mater, usually caused by tearing of bridging veins.
Subarachnoid hemorrhage: Bleeding into the subarachnoid space, often due to a ruptured aneurysm.
What is the inferior petrosal sinus, and where does it drain?
The inferior petrosal sinus is a paired sinus that drains the cavernous sinus into the internal jugular vein.
What is the superior petrosal sinus, and where does it drain?
The superior petrosal sinus is a paired sinus that runs along the upper border of the petrous temporal bone. It drains into the sigmoid sinus.
What is the basilar sinus, and where is it located?
The basilar sinus is a venous plexus located at the base of the skull. It connects the cavernous sinuses and drains into the vertebral veins.
What is the intercavernous communication, and what is its function?
The intercavernous communication is a connection between the left and right cavernous sinuses. It allows for the exchange of blood between the two sinuses.
Where does the sphenoparietal sinus drain into
The sphenoparietal sinus is a small sinus that drains into the cavernous sinus. It is located near the sphenoid bone.
What is the clinical significance of the subdural space?
The subdural space is a potential space that can fill with blood after trauma, leading to a subdural hemorrhage.
What is the clinical significance of the epidural space?
The epidural space contains spinal nerve roots and adipose tissue. It is used for epidural anesthesia and can also be a site for epidural hematoma.
What is meningitis, and what are its symptoms?
Meningitis is inflammation of the meninges, often caused by infection. Symptoms include headache, fever, and stiff neck.
What is an epidural hematoma, and what causes it?
An epidural hematoma is a collection of blood in the epidural space, often due to a skull fracture. It can cause increased intracranial pressure and requires urgent treatment.
What is a subarachnoid hemorrhage, and what is a common cause?
A subarachnoid hemorrhage is bleeding into the subarachnoid space, often caused by a ruptured cerebral aneurysm. It presents with a sudden, severe headache.
What is hydrocephalus, and what causes it?
Hydrocephalus is a condition where there is an abnormal accumulation of cerebrospinal fluid (CSF) in the brain, leading to increased intracranial pressure. It can be caused by obstruction of CSF flow or impaired CSF reabsorption.
What is the pia mater, and what is its function?
The pia mater is the innermost meningeal layer, highly vascular, and provides nourishment to the brain and spinal cord. It follows the contours of the brain, covering the gyri and lining the sulci.
Where does the arachnoid mater line sulci
In the longitudinal fissure
Where does the leptomeninx develop from
Neural crest cells
