Module 9 Flashcards
Name the 3 layers of meninges
Dura mater
Arachnoid
Pia mater
What are meninges?
3 layers of connective tissue that protect and surround the brain and spinal cord
Which layer of connective tissue is the dura mater?
Outermost meningeal layer
How many layers does the dura mater of the brain have?
Two layers
Name the two layers of dura mater
Outer: periosteal (periosteum of skull)
Inner: “the flax” meningeal layer
What is epidural space?
Space between outer dura and skull
What is a extradural hemorrhage?
Bleeding in the epidural space
What is subdural?
Space between inner dura (meningeal layer) and arachnoid
Describe the location of the inner dura mater
Between cerebral hemisphere
Over the tentorium cerebelli
Between cerebellar hemisphere
Over the diaphragma sella
What layer of connective tissue is the arachnoid layer?
The middle layer
What is the subarachnoid space?
Space between pia and arachnoid
CONTAINS CSF (Cerebrospinal fluid) and blood vessels
What are trabeculae?
Thin strands of connective tissue WITHIN the subarachnoid space
What are arachnoid villi?
Projections of arachnoid in the dural sinuses (blood vessel)
What is the role of the arachnoid villi?
Pressure sensitive valves that open in ONLY ONE direction!
Release CSF from subarachnoid space into superior sagittal sinus
Where’s do the arachnoid villi valves drain?
Into vascular system:
Releases CSF
What is another name for arachnoid villi?
Arachnoid granulation
What does subarachnoid space have in it?
CSF and blood vessels
If the rupture of an aneurysm happens, which space would it typically occur in?
Subarachnoid space
Which layer of connective tissue is the pia mater?
Innermost layer
Which part of the spinal cord does the pia mater form?
Filum teminale
What does the pia mater attach to?
The brain
Which layer of the pia mater contains the blood vessels that nourish neural tissue?
The vascular layer
How many dura mater layers does the spinal cord have?
One layer
What does the dura merge with on the spinal cord?
The pia mater (film terminale)
FORMS coccygeal ligament
Where do the arachnoid of the spinal cord extend to?
Cauda equina
Name the 4 ventricles of the brain
(2) lateral
Third ventricle
Fourth ventricle
Name the areas where CSF is located?
All ventricles
Subarachnoid space
What is the actually weight of the brain? What is the weight of the brain while in CSF?
1400 g
25 g
What is choroid plexus?
Vessels composed on pia mater and ependymal tissue
Where is the choroid plexus located?
Floor of the fourth ventricle
Roof of the 3rd and 4th ventricle
What is the function of the choroid plexus?
Creates CSF
Maintains the chemical stability of the CSF
Do all ventricles have choroid plexus?
YES!!
TRUE/FALSE: Are both lateral ventricles in one hemisphere?
No! There’s one lateral ventricle in each hemisphere
What is ependyma?
Layer of glial tissue that lines the ventricles and central canal of the SC
Name the 4 parts of the lateral ventricle (include the cerebral lobe associated with it)
Anterior horn (frontal lobe) Body (parietal lobe) Posterior horn (occipital lobe) Inferior horn (temporal lobe)
Where is the third ventricle?
In the diencephalon
Between the thalami
Which area does the third ventricle open to?
Cerebral aqueduct (connects 3rd and 4th ventricle)
Which area does the 4th ventricle open to?
2 lateral foramina of Luschka
PUTS CSF into the subarachnoid space via the formen of the Magendie
List the order of the CSF circulation
Lateral ventricles Formen of Monro Third ventricle Aqueduct of Sylvius Fourth ventricle Foramina of Luschka/Magendie Subarachnoid space (cisterna mag.) Cerebral and spinal circulation THEN IT HAPPENS ALL OVER AGAIN
What is the volume of CSF in the ventricles compared to the subarachnoid space?
60 ml: ventricles
90 ml: subarachnoid space
How much CSF is formed a day?
500-700 ml
Which is more; CSF pressure OR venous sinus pressure?
CSF pressure
What happens if CSF is obstructed?
Increased intracranial pressure
Papilledema/choked disc
When does hydrocephalus happen?
Dissociation between production and absorption rate of CSF
What are the 3 types of hydrocephalus?
Obstructive
Communicating
Compensating
What causes obstruction hydrocephalus?
Tumor
Structural anomaly
Inflammatory process
Increases CSF volume/ pressure
What causes communicating hydrocephalus?
Problem with formation/absorption of CSF
east flow to subarachnoid but blockage in the subarachnoid
What causes compensating hydrocephalus?
Characteristic of dementia
Enlarged ventricles and increased CSF volume
How do you treat hydrocephalus?
Drain excess fluid
Ventriculoperitoneal (VP) shunt
