N4 CNS Meninges, Ventricles, Blood Supply Flashcards
The meninges of the brain are ____
Connective tissue layers
What are the three meningeal spaces and what are their features?
Epidural: above dura matter
Subdural: between dura and arachnoid
Subarachnoid: inside arachnoid layer, filled with CSF and blood vessels
Two meningeal spaces are considered potential spaces while the other is a real space, which are which?
Epidural and subdural are potential while subarachnoid is an actual space
What are the three layers of meninges?
Dura matter (thickest)
Arachnoid (web like)
Pia matter (thin)
These are listed from outside to inside
The spinal cord is also surrounded by meningeal layers, these are ….
Dura matter
Arachnoid matter
Pia matter
These are the same as the brain
The spinal cord has two special connections that help maintain its position, what are they and what are their connections?
- Filum terminale internum: anchors spinal cord to dural sac, inside meningeal layer
- Filum terminale externum: anchors dural sac to vertebral column, outside meningeal layer
The spinal cord also contains a meningeal space that is filled with CSF, what is the space called?
Subarachnoid
What are dural reflections?
Areas where dura matter separates part of the brain
What are the three main dural reflections?
Falx cerebri: separates the cerebral hemispheres into left and right
Tentorium cerebelli: separates the occipital lobe and the cerebellum
Falx cereblli: separates the cerebellum into left and right hemispheres
What are the unpaired dural venous sinuses?
Superior sagittal sinus, inferior sagittal sinus, vein of Galen, straight sinus and confluence of sinuses
What are the paired dural venous sinuses?
Transverse sinus, sigmoid sinus, cavernous sinus
What is the purpose of the dural venous sinuses?
Drain blood from the brain back to the heart
The internal jugular vein is where the majority of the blood drains back to the ___
Heart
What path does blood follow through the dural venous sinuses?
Superior sagittal sinus > Inferior sagittal sinus > confluence of sinuses > transverse sinus > sigmoid sinus > internal jugular vein
How does CSF flow through the ventricular system?
2 Lateral ventricles > interventricular foramen > third ventricle > cerebral aqueduct (of Sylvius) > fourth ventricle > foramina of Magendle and Luschka > brain or spinal cord
Where is CSF produced?
Choroid plexuses that line all four ventricles
What is the general flow of CSF through the CNS?
Ventricles > subarachnoid space > dural venous sinuses
What sinus is mainly responsible for returning CSF back into the blood supply?
Superior sagittal sinus
What is hydrocephalus?
Build-up of fluid in the ventricles in the brain
What are the two types of hydrocephalus?
- Obstructive (non-communicating)
- Communicating
What occurs during obstructive or non-communicating hydrocephalus?
CSF flow is obstructed within the ventricular system
Example: tumor causing aqueductal stenosis (narrowing of the cerebral aqueduct)
What occurs during communicating hydrocephalus?
CSF flow is not obstructed within the ventricular system
Example: overproduction of CSF or poor reabsorption of CSF
What type of issues could hydrocephalus lead to?
Cortical damage due to pressure on brain tissue
Blood supply is provided to the cerebrum through ___ of ____ that is mainly supplied by the ____ ___ arteries and the ____ artery
Circle of Willis
Internal carotid arteries
Basilar artery
What are the additional arteries of the Circle of Willis besides the internal carotid arteries and the basilar artery>
Posterior cerebral, posterior communication, middle cerebral, anterior cerebral and anterior communicating arteries
The middle cerebral artery supplies which part of the cerebrum?
Lateral cerebral hemispheres
The anterior cerebral artery supplies which part of the cerebrum?
Medial frontal and parietal lobes
The posterior cerebral artery supplies which part of the cerebrum?
Medial temporal and occipital lobes
The lenticulostriate arteries are deep vascular territories that branch off ____ and supply ____
Branch off the middle cerebral artery
Supplies globus pallidus, putamen, caudate nucleus (basal nuclei) and internal capsule
The thalamoperforating and thalamogenicualte arteries are deep vascular territories that branch off the ___ and supply ____
Posterior cerebral artery
Supply the thalamus
Blood supply is provided to the midbrain via the ___ artery
Posterior cerebral artery
Blood supply is provided to the pons via the ___ arteries
Basilar artery, superior cerebellar artery, anterior inferior cerebellar artery
Blood supply is provided to the medulla via the ___ arteries
Vertebral artery, anterior spinal artery, PICA (posterior inferior cerebellar artery), posterior spinal artery
Blood supply is provided to the cerebellum via the ___ arteries
Superior cerebellar artery, AICA (anterior inferior communicating artery), PICA (posterior inferior communicating artery)
All the artery names contain the word cerebellum
Blood supply is provided to the spinal cord via the ___ arteries
Anterior spinal artery, posterior spinal artery
All arteries have the word spinal in them
What is an epidural hematoma?
Pooling of blood in the epidural space that creates space between the dura and the skull
Leads to headache, confusion, lethargy
What is a subdural hematoma?
Blood pools in the innermost part of the dura
Leads to either absent symptoms or headache, confusion and lethargy (like an epidural hematoma)
