Neuro 1.2 - meninges, ventricles, cisterns

dura, arachnoid, and pia

what are the three layers of meninges

leptomeninges

together, the arachnoid mater and the pia mater are called ____________

fibroblasts (different functions for each layer though)

Generally the layers of the meninges are made up of __________

dura

the _________ meningeal layer is close to the skull

arachnoid

the _________ meningeal layer is related to CSF

pia

the _________ meningeal layer is conformed to brain and spinal cord

S2

the subarachnoid space continues down the spine until about ______ level

superior sagittal sinus

the two layers of dura split and form a big sinus called _______ _______ ________

periosteal; meningeal

the dura mater has two layers, the _________ layer is the outer layer and the ________ layer is the inner layer

foramen magnum

the outer periosteal layer of the dura mater lines the cranium but stops at the ___________ ___________

connective

the two layers of dura mater are made of collagenous __________ tissue

sinus

__________ is a channel carrying venous blood

longitudinal cerebral; crista galli; internal occipital protuberance

the falx cerebri is suspended in the __________ _________ fissure and rostrally attached to the ________ ________ and caudally attached ot the __________ __________ _________

F

T/F: the great vertebral vein is considered a sinus

endothelial

the dural sinuses are lined with ____________ cells

falx cerebri

the dural sinuses border the _______ _______

• superior sagittal sinus

• inferior sagittal sinus

• confluence of sinuses

• straight sinus

what are the 4 dural sinuses

superior (or dorsal)

where is the falx relative to the corpus callosum?

medial

where is the fax relative to the cerebral hemispheres

turkish saddle/sella turcica

where is the pituitary gland located

straight sinus (also where the great cerebral vein is draining) → confluence of sinuses (merges with superior sagittal sinus) → transverse sinus (also where superior petrosal sinuses drains from the cavernous sinus) → sigmoid sinus → internal jugular vein

what is the flow starting from the inferior sagittal sinus

pia

the _______ meningeal layer are on the gyri of the brain

vessels (can cause bleed)

a lot of ________ are located in the subarachnoid space

cavernous

the _________ sinus is on either side of the sella turcica/turkish saddle/pituitary gland

occipital; petrosal ridge (temporal bone); posterior clinoid process

the tentorium cerebelli is attached caudally to the __________ bone, laterally to the _______ _______ and anteriorly to the _______ ________ _______

cerebellum; occipital

the tentorium cerebelli is on top of the _________ and under the __________ lobe

superior petrosal ridge → transverse sinus → sigmoid sinus → internal jugular vein

how does content from the cavernous sinus get to the internal jugular vein

brainstem

the tentorial notch creates space for the ___________

lateral and caudal

where is the tentorium cerebelli located in relation to the tentorial notch

• lobes of the cerebrum

• diencephalon

what are the 2 neural structures located in the supratentorial compartment

• cerebrum

• medulla

• pons

what are the 3 neural structures located in the infratentorial compartment

sella turcica (over the pituitary gland); posterior clinoid processes (what else attaches here? the tentorium cerebelli)

the diaphragma sellae passes over the _______ ______ going from anterior to posterior and attaches to the _______ _______ ________ posteriorly

cavernous sinuses

the _____________ ________ forms the walls of the diaphragma sellae as it passes over the sella turcica

• internal carotid artery

• CN III (oculomotor)

• CN IV (trochlear)

• CN Vi (ophthalmic division of trigeminal n.)

• CN Vii (maxillary division of trigeminal n.)

• CN VI (abducens)

what runs through the cavernous sinus

middle meningeal

___________ is the primary artery to the dura

maxillary → external artery

the middle meningeal artery is a branch off of the ___________ artery which is a branch off of the __________ artery

trigeminal CN; CN 2 and 3

the ________________ is the main nerve supply of the dura in the anterior and middle fossae

the _______________ is the main nerve supply for the posterior cranial fossa

middle meningeal

extra-dural bleed is usually caused by rupture to the _______________ artery

arachnoid villi

the __________ __________ allow CSF to go from the subarachnoid space to the venous sinus by protruding through the dura mater and into the sinus

granulations

the arachnoid villi are also called

subarachnoid space

valves of the arachnoid villi will open when there is more pressure in the subarachnoid space or superior sagitaal sinus

cisterns

_________ are bigger areas of subarachnoid space

cisterns

___________ occur where the brain moves away from the skull due to the shape of neural structures

• CSF

• arteries

• veins

• cranial nerves (sometimes)

what are the 4 things that cisterns usually contain

L2

at what level does the spinal cord end

T (it is not because it is part of the ventricular system)

T/F: the third ventricle is not a cistern

trochlear (CN IV)

What cranial nerve emerges dorsally and travels through the Ambient cistern?

superior and inferior colliculi

The Superior (Quadrigeminal) cistern is anterior to the tentorium cerebelli and posterior to what?

cerebral peduncles

Interpeduncular cistern (fossa) is found between what midbrain structures?

oculomotor

What other cranial nerve emerges from the midbrain?

pons

Prepontine cistern is anterior to what part of the brainstem?

• cerebellum

• medulla

• foramen magnum

• largest cistern

the dorsal cerebellomedullary cistern (cisterna magna) is bordered by what 4 structures

cauda equina; filum terminale internus; filum terminale externus

contents in the lumbar cistern

• _______ _______: spinal nerves

• _______ _______ ______: anchoring the conus medullaris (end of spinal cord) to the end of the dural sac

• _______ _______ ______: anchors the dural sac to the coccyx (coccygeal ligament)

pia (anchors the middle of the conus medullaris to the end of dural sac)

filum terminale internus is made of _______ mater

dural

filum terminale externus is made of _______ mater

Denticulate ligaments

_________ __________ are thickened pia running longitudinally along SC attaching to arachnoid-lined dural sac

pia

__________ mater hugs the gyri and follows every sulcus of brain and SC

blood vessels; endothelial

pia mater surrounds the _______ ________ in the subarachnoid space and then fuses with ________ cells

epidural

epidural or spinal anesthesia:

can be done at any level of the spine

spinal anesthesia (L2 is where the spinal cord stops)

epidural or spinal anesthesia:

can only be done below low

spinal anesthesia

epidural or spinal anesthesia:

lasts for one to two hours

epidural

epidural or spinal anesthesia:

catheter so it can continue as needed (drip method)

lateral

the ___________ ventricles are in the cerebral hemispheres

third

the _________ ventricle is located midline, vertical, diencephalon

fourth

the ___________ ventricle is pyramid shaped, pons and medulla, cerebellum

3 and 4

the cerebral aqueduct is between what two ventricles

• frontal horn

• body

• atrium

• posterior (occipital) horn

• inferior (temporal) horn

temporal horn

what are the five parts of the lateral ventricle?

which one is closest to the hippocampus?

interventricular foramen

CSF from the lateral ventricle enters the third ventricle through the __________ __________

cerebral aqueduct

the third ventricle communicates caudally with the ________ _________

• supraoptic

• infundibular

• suprapineal

• lamina terminalis

• anterior and posterior commissures

what are the five recesses (small outpocketings) in the 3rd ventricle

cerebral aqueduct

the ___________ ___________ is an extension of the 3rd ventricle through the midbrain to the 4th ventricle

T (the space is very narrow)

T/F: there is no choroid plexus in the cerebral aqueduct

gray; periaqueductal

the cerebral aqueduct is surrounded by a sleeve of ________ mater, which is also called _________

fourth

the _________ ventricle is the apex of the cerebellum

• central canal

• foramen of magendie

• rhomboid

the fourth ventricles pathways:

• caudally tapers into the _______ _________ of the spinal cord

• lateral recesses empty into cerebellopontine angle thru the _________ _________ which is the roof

• the flood is the __________ fossa

foramen of luschka and magendie; fourth

what are the only two openings between the ventricles of the brain and the subarachnoid space? what ventricle are the found in?

luschka

in the fourth ventricle, the foramen of ____________ in the fourth ventricle leads to the subarachnoid space

magendie

in the fourth ventricle, the foramen of _________ is a central foramen and leads to the subarachnoid cisterna magna

tight; endothelial

the blood brain barrier is made of _________ junctions and __________ cells

ependymal; simple cuboidal epithelium

the ventricles are lined with ____________ cells, also known as _________ ________ _________

choroid plexus; lateral

CSF is produced by the _________ ________ mostly in the _________ ventricle

fenestrated; connective; cuboidal

structure of the choroid plexus:

• __________ capillaries

• _________ tissue core

• __________ epithelium with microvilli

blood capillary → connective tissue → cuboidal epithelium (gets filtered, tight junctions) → ventricular space → subarachnoid space

what is the flow of things in the choroid plexus starting from the blood capillary

450-750; 400

the choroid plexus filters about ______-______ mL of CSF/day and resorbs about _____ mL

normal = 15-45

abnormal = 100

normal and abnormal values of protein in CSF

protein

abnormal levels of ______ is the CSF could indicate tumor, bleed, infection

< 10; 200-300; 1,000-20,000

normal values of neutrophils in CSF

abnormal values of _____-____ could indicate syphilitic meningitis

abnormal values of ______-______ could indicate bacterial meningitis

60; < 40

normal and abnormal values of glucose in CSF

glucose

abnormal values of ___________ could indicate CNS infection

CSF

________ reduces momentum and acceleration of the brain

CSF

____________ acts as a lymphatic system for the brain by removing waste products

cerebral aqueduct (connection from third ventricle to fourth ventricle, very thin)

where is the CSF flow most vulnerable to direct obstruction or indirect pressure

magendie

the foramen _________ drains into the cisterna magna

luschka

the foramen ____________ drains into the subarachnoid space on the sides of the medulla and pons

open

if the CSF pressure is more than the blood pressure the arachnoid granulation valve (open or closes)

closes

if the CSF pressure is less than the blood pressure the arachnoid granulation valve (opens or closes)

10-20

CSF pressure is ____-_____ cm H2O depending on body position

headache (due to compression on skull or irritation of meninges)

____________ is the most common symptom of an intracranial mass lesion

papilledma

____________ is dilation of the optic disc which may occur with an increase in intracranial pressure

skull and dura mater

an epidural hematoma is between the ________ and the ___________