neuro 2 Flashcards
what protects the CNS
- bone
-skull
-vertebral collumn - connective tissues
-meningeal layers
dura matter
arachnoid mater
pia mater - fluid
-cerebrospinal fluid
what are the 3 meningeal layers
dura mater= tough outer layer
arachnoid mater= web like middle layer
pia mater= delicate thin inner layer
meninges of the brain
skull
epidural space (pathoglogy)
layer 1: dura mater
1. periosteal (adhere to bone)
2. meningeal (forms dural folds for venous sinuses)
subdural space (pathology)
layer 2: arachnoid mater
-arachnoid villus/ granulations are small protrusions of arachnoid through the dura mater
space 1: subarachnoid space
-CSF is here
layer 3: Pia mater
-tightly adhered to neural tissue
which spaces are pathology and which one isn’t for the brain
*
pathology:
epidural space (btwn skull and dura)
subdural (btwn dura and arachnoid)
normal:
subarachnoid (btwn arachnoid and pia)
what are the layers of dura matter
periosteal dura (outer)
meningeal dura (inner)
-forms folds of tissue that seperate cranial cavity into sections
-seperated by venous sinuses
what are the dural reflections
-folds that seperate the cranial cavity into compartments
-falx cerebri: divides hemispheres of cerebrum (L and R)
-tentorium cerebelli: divides the cerebrum from the cerebellum
fall cerebelli: divides the two hemispheres of the cerebellum
dura sinuses
superior sagittal sinus –> confluence of sinuses
inferior sagital sinus –> straight sinus –> confluence of sinus
from confluence of sinus –> transverse sinus –> sigmoid sinus –> internal jugular
- these all drain the cortex
the cavernous sinus drains the eye, nose, mouth
which sinus is seperate from the rest
the cavernous sinus drains the eye, nose, mouth
meninges of the spinal cord
vertebral column
space 1: epidural space
layer 1: dura mater
-1 layer; meningeal layer
subdural space (pathology)
layer 2: arachnoid mater
-web like
space 2: subarachnoid space
-CSF
layer 3: pia mater
-adhere to neural tissue
main different between meninges of brain and spinal cord
in spinal cord there is an epidural space which isn’t pathological and the dura mater only has 1 layer
dura mater of spinal cord
what does it have?
and which space is above it
sac that covers the spinal cord with bony attachments at foramen magnum, C1-C2 and the level of S2 “dural sleeve”
-surrounding this layer is the epidural space which contains fat, CT, blood vessel
arachnoid of spinal cord
and which space is deep to it
middle layer of avascular CT with collagen and elastic fibers
deep to the arachnoid layer is the subarachnoid space containing CSF
pia mater of spinal cord
what ligaments are made
denticulate liagemtns are thickenings of the pia mater that suspend the spinal cord in the middle of the dural sheath
located between ventral and dorsal nerve roots
protect the spinal cord against shock and sudden displacement/trauma
parts of termination of the spinal cord
conus medullaris
cauda equina
dural sac/sleeve
lumbar cistern
filum terminale
conus medullaris
-end of spinal cord
-L1/2 in adults
-L4 in kids
cauda equina
-remaingin spinal cords
-horses tails
dural sac/sleeve
dura mater surrounds cauda quinta ending at S2 forming a sac of sleeve
lumbar cistern
filled with CSF
-enlargement of subarachnoid space between conus medullaris (L2) and end of dural sac (S2)f
filum terminale
-tethers spinal cord to coccyx
-not a neural structure
-extension of pia mater
-runs from census medullariei to coccyx; anchors dural sac and conus medullaris to coccyx
what is the ventricular system of the CNS made of
2 lateral ventricles (found in all 4 lobes)
third ventricle (found between thalamic nuclei)
cerebral aqueduct (runs through midbrain)
fourth ventricle (found between pons and cerebellum)
–> communicating network of cavities deep within the tissue of the brain
choroid plexus and CSF
choroid plexuses are specialized arterial plexuses located within the ventricular spaces which functions to produce CSF from arterial blood
-this clear fluid flows through the ventricular system and performs the following functions;
-serrves as nutrient delivery and waste removal system for brain tissue
-enters subarachnoid space to provide fluid cushion around brain and spinal cord
-unidirectional flow of CSF
-absorbed by the venous system after it performed its role in the CNS
what is CSF made of an exit as
made of arterial blood and exits alongside venous blood
what is the flow of CSF
left and right lateral ventricles –> (inter ventricular foramina) –> 3rd ventricle –> (cerebral aqueduct) –> 4th ventricle –> continues inferiorly to central canal
OR at 4th ventricle exits system via 2 lateral or 1 median foramina (circulates external to brain and spinal cord) –> subarachnoid space –> (arachnoid granulations) –> venous sinuses –> internal jugular vein –> heart for reoxygenation
lateral
3rd
4th
subarachnoid
granulation/villi
venous sinus
heart
what are the 2 main blood supply systems of the brain
- vertebra-basilar system
-vertebral arteries
-basillar arteries
-posterior cerebral arteries (occipital lobe cortical blindness)
-posterior communicating arteries
-posterior anterior inferior cerebrellar artery
-superior cerebellar - carotid system
-middle cerebral artery
-anterior cerebral artery
-anterior communicating artery
which arteries make up the circle of willis (6)
–> connects anterior and posterior circulations
- anterior communicating
- anterior cerebral
- internal caroitd
- posterior communicating
- posterior cerebral
which lobes do the anterior, middle and posterior cerebral arteries supply?
which is worse to damage
anterior- frontal, parietal
middle- frontal, parietal, temporal
–> worst to damage
posterior- occipital, temporal, parietal
arteries of spinal cord
cervical spine: anterior spinal artery and vertebral artery
thoracic vertebrae: posterior intercostal arteries
lumbar vertebrae: lumbar arteries
posterior spinal artery does 1/3
anterior spinal artery does 2/3
