Neuroanatomy 2 Flashcards
The CNS is surrounded and protected by three membranes of connective tissue collectively known as
as meninges:
the dura mater
arachnoid mater,andpia materfrom outside to inside.
what is the 3 protective layers of the CNS
- bone
- connective tissue
- fluid - CSF
is a thick layer of dense connective tissue that attaches to the inner surface of the neurocranium in the skull but is separated from the walls of the vertebral canal by the epidural space.
dura mater
The dura mater surrounding the spinal cord ends at the level of vertebra ____
S2
The dura mater within the skull comprises an outer _________ layer and an inner _______ layer.
periosteal and meningeal
the __________ layer of the dura mater is attached to the inner surface of the cranial cavities
periosteal layer
the meningeal layer of the dura mater separates from the periosteal layer in several locations to form two distinct structures:
- Dural reflections
- Dural sinuses
what are the three reflections:
Falx cerebri
Tentorium cerebelli
Falx cerebelli
which dural reflection can be described as a sagittal sickle shape reflection of the dura mater that occupies the longitudinal fissure of the cerebrum and partially separates the cerebral hemispheres.
Falx cerebri
which dural reflection can be described as a tent-like horizontal sheet that intervenes between the cerebellum and occipital lobe of the cerebral hemispheres. It is notched anteriorly to provide a passage for the midbrain.
Tentorium cerebelli
which dural reflection can be described as a less prominent vertical reflection of the dura in the sagittal plane along the vermis that partially separates the cerebellar hemispheres?
Falx cerebelli
what are venous channels between the two layers of the cranial dura mater? The superficial veins of the brain are collected by these
dural sinuses
The main dural sinuses include:(6)
The cavernous sinuses
superior and inferior sagittal sinuses
The straight sinus
The transverse sinuses
The sigmoid sinuses
Dura Sinuses: are a pair of sinuses located in the middle cranial fossa on either side of the hypophyseal fossa of the sphenoid bone and collect the venous blood of the orbital cavity contents.
The cavernous sinuses
Dura Sinuses: is an unpaired short sinus that receives the posterior end of the inferior sagittal sinus and great cerebral vein and joins the posterior end of the superior sagittal sinus.
The straight sinus
Dura Sinuses: are unpaired sinuses contained within the superior and inferior margins of the falx cerebri, respectively.
The superior and inferior sagittal sinuses
Dura Sinuses: paired sinuses housed in the posterior margin of the tentorium cerebelli and receive the superior sagittal and straight sinuses.
The transverse sinuses
Dura Sinuses: paired sinuses located in a groove on the interior surface of the mastoid process of temporal bones. These sinuses receive all other dural sinuses (directly or indirectly) and empty into the internal jugular veins.
The sigmoid sinuses
Named for its “web-like” appearance. What is this layer called?
Arachnoid mater
what do arachnoid villus / arachnoid granulations do?
are projections of the arachnoid membrane (villi) into the dural sinuses that allow CSF to pass from the subarachnoid space into the venous system
which layer is tightly adhered to neural tissue itself
Pia mater
which dural reflection divides two hemispheres of the cerebrum
flax cerebri
which dural reflection divides the cerebrum from the cerebellum
tentorium cerebelli
which dural reflection divides the two hemispheres of the cerebellum
flax cerebelli
The arachnoid mater is separated from the pia mater by__________space, mainly containing the CSF
subarachnoid
The subarachnoid space surrounding the spinal cord continues inferiorly and ends at the level of vertebra ___
S2
what is the lumbar cistern
- region in the lower back
- Enlargement of the subarachnoid space that occurs at the conus meullaris and end of dural sace (around the causa equina)
- Site for lumbar puncture
is a delicate, thin layer of connective tissue that is intimately in touch with the surface of the brain and spinal cord. This layer follows the contours of the brain and spinal cord and carries the blood vessels to the depth of the nervous tissue of the CNS
pia mater
are thickenings of the pia mater that suspend the spinal cord in the middle of its dural sheath. Anchor the cord to the dural sheath.
Denticulate ligaments (tooth-like extensions)
where are Denticulate ligaments located and what is their role?
located between ventral and dorsal nerve roots
Protect the spinal cord against shock and sudden displacement/trauma
The___________is an extension of the pia mater arising from the conus medullaris that extends inferiorly and fuses with the arachnoid and dura mater to anchor the spinal cord to the coccyx.
filum terminale
Anchor conus medullaris and dural sac to the coccus
Sac that covers the spinal cord with bony attachments at the foramen magnum, C1-C2 and at the level of S2 “dural sleeve”
Dura Mater of spinal cord
what is the surrounding layer of the dura mater in the spinal cord called? What does it contain? (3)
Surrounding this layer is the epidural space which contains fat, CT and blood vessels
Middle layer of avascular CT with collagen and elastic fibres
Deep to the ________ layer is the subarachnoid space containing CSF
arachnoid
what is the end of spinal cord called? Where does this happen in adults vs in child?
conus medullaris
L1/2 in adults
L4 in children
the remaing sinap nerves. Referred to as
“horses tail”
cauda equina
The nervous system is developed from the embryonic neural tube. The caudal part of the neural tube forms the ________, whereas the cephalic part forms the __________
spinal cord, cerebral vesicles
The lumen of the neural tube in the brain is larger and develops into____________
cerebral ventricles
The cerebral ventricles house a specialized vascular plexus known as the________ _______
choroid plexus.
This plexus is responsible for the secretion of the____________ __________that circulates in all cerebral ventricles, the central canal of the spinal cord, and subarachnoid space.
cerebrospinal fluid (CSF)
There are four ventricles within the brain:
2 lateral, a third and a fourth
The ________ ventricle is an irregular and narrow space within the diencephalon between the left and right thalami
third
The third ventricle is connected to the fourth ventricle through the cerebral __________that passes through the midbrain
aqueduct
This ventricle is a diamond-shaped space that is bounded by the pons and upper part of the medulla anteriorly and the cerebellum posteriorly
fourth ventricle
The fourth ventricle is connected to the central canal of the spinal cord (inferiorly), to the third ventricle (superiorly), and through two lateral apertures(foramina of ______) and amedian aperture(foramen of ________) to the subarachnoid space.
Luschka and Magendi
In each cerebral hemisphere, there is an amorphous space known as the _______ ventricle
lateral
Each lateral ventricle is connected to the third ventricle through the________ foramen(of Monro).
interventricular
CSF passes from the lateral ventricles to the 3rd ventricles through the ___________ foramen
interventricular foramen
CSF passes from the 3rd ventricles to the 4th ventricles through the ___________
cerebral aqueduct
CSF passes from the 4th ventricles to the subarachnoid space through the ________ and ________ apertures
median and lateral apertures
