N4: CNS meninges, ventricles, blood supply

Question 1

Meningeal spaces

Answer 1

epidural (above dura mater, potential space)
subdural (below dura mater, potential space)
subarachnoid (filled w/cerebrospinal fluid)

Question 2

Three layers of meninges?

Answer 2

dura mater
arachnoid
pia mater

Question 3

What are meninges?

Answer 3

Layers of tissue that protect the brain

Question 4

Spinal meninges?

Answer 4

dura mater
arachnoid
pia mater

filum terminale internum
-anchors spinal cord to dural sac
filum terminale externum
-anchors dural sac to vertebral column
subarachnoid space
-contains CSF

Question 5

Dural reflections?

Answer 5

falx cerebri- separates brain hemispheres
tentorium cerebelli- separates occipital lobe from cerebellum
falx cerebelli- separates cerebellum into right and left hemispheres

Question 6

Dural venous sinuses?

Answer 6

*sinuses= diff. histology than veins

Collect blood from brain and transport it back to the heart.

unpaired – superior sagittal sinus (at the top, most CSF gets returned here), inferior sagittal sinus, vein of Galen, straight sinus,
confluence of sinuses

paired – transverse sinus, sigmoid sinus (exit from dura mater and becomes internal jugular vein to return to the heart), cavernous sinus

Question 7

Dura vein sinuses flow of blood?

Answer 7

Confluence of sinuses-> transverse sinus-> sigmoid sinus-> internal jugular vein

Question 8

Ventricular system?

Answer 8

two lateral ventricles-> interventricular foramen (of Monro)-> third ventricle-> cerebral aqueduct (of Sylvius)-> fourth ventricle-> foramina of Magendie and Luschka (2 of them)

Question 9

CSF and choroid plexuses?

Answer 9

CSF produced by choroid plexuses which line all four ventricles
CSF flows from ventricles to subarachnoid space to dural venous sinuses

Regulate substances in blood and ventricles, so fluid is different in the two.

Question 10

Hydrocephalus

Answer 10

Increase in size of the ventricles.

obstructive (non-communicating)
-CSF flow is obstructed within ventricular system;
an example is a tumor causing aqueductal stenosis
(narrowing of the cerebral aqueduct)

communicating
-CSF flow is not obstructed within ventricular system;
examples include overproduction of CSF or a problem with reabsorption of CSF

Question 11

Blood supply of cerebrum?

Answer 11

Circle of Willis- circle of blood vessels that can rescue an area that may have lost blood supply

sources: basilar artery (forms from 2 vertebral arteries), internal carotid arteries
component arteries: posterior cerebral (PCA), posterior communicating,
middle cerebral (MCA), internal carotid, anterior cerebral (ACA), anterior communicating

Question 12

Cerebrum vascular territories?

Answer 12

middle cerebral artery (MCA)
-lateral cerebral hemispheres

anterior cerebral artery (ACA)
-medial frontal and parietal lobes

posterior cerebral artery (PCA)
-medial temporal and occipital lobes

Question 13

Deep vascular territories?

Answer 13

-lenticulostriate arteries (of middle cerebral artery) supply globus pallidus, putamen, caudate nucleus, and internal capsule

-thalamoperforating and thalamogeniculate arteries
(of posterior cerebral artery) supply thalamus

Question 14

Blood supply of midbrain?

Answer 14

posterior cerebral artery
-passes over midbrain and gives off branches

Question 15

Vascular territories of midbrain?

Answer 15

quadrigeminal (lateral)

paramedian (medial)

Question 16

Blood supply of pons?

Answer 16

basilar artery, superior cerebellar artery, AICA (anterior inferior cerebellar artery)
-supply some blood to pons on the way to the cerebellum

Question 17

Vascular territories of pons?

Answer 17

AICA (lateral)

paramedian (medial)

Question 18

Blood supply of medulla?

Answer 18

vertebral artery, anterior spinal artery, PICA (posterior inferior cerebellar artery), posterior spinal artery
-supply blood to medulla

Question 19

Vascular territories of medulla?

Answer 19

PICA (posterior)

vertebral (lateral)

anterior spinal (medial)

Question 20

Blood supply of cerebellum?

Answer 20

superior cerebellar artery, AICA, PICA (inferior)
-supply the cerebellum

Question 21

Blood supply of spinal cord?

Answer 21

anterior spinal artery, posterior spinal artery (right and left)
-supply the spinal cord

Question 22

Vascular territories of cervical spinal cord?

Answer 22

posterior spinal (posterior)

anterior spinal (anterior)

Question 23

Epidural hematoma?

Answer 23

blood dissects the dura mater from the skull
-blood pools in area between dura and skull
-outside of dura
neurological deficits include headache, confusion, lethargy

Question 24

Subdural hematoma?

Answer 24

blood dissects open the dura border cell layer of innermost dura mater
-blood pools within innermost part of dura

neurological deficits may be absent or similar to epidural hematoma

Question 25

Subarachnoid hematoma?

Answer 25

blood within the subarachnoid space

neurological deficits include headache, neck stiffness, vomiting, nausea