Neuro: Ch 4 Meningeal Coverings Of The Brain And Spinal Cord

Front 1

What are the jobs of the meninges?

Back 1

-cover and protect the CNS
-protect blood vessels and enclosed venous sinuses
-contain CSF
- partition skull

Front 2

How does the brain hang out in the head?

Back 2

It floats in cerebral spinal fluid and is held in place by the meninges so that the brain moves with the skull

Front 3

What are the 3 layers of the meninges

Back 3

dura
arachnoid
pia

Front 4

dura matter

Back 4

- most external, thick fibrous, collagen membrane
-periosteal layer attaches to the skull
-meningeal layer is closer to the brain, but not tight to it
-dural septa limit mvt of the brain
-only layer innervated

Front 5

Falx cerebri

Back 5

— in the longitudinal fissure; attached to crista galli

Front 6

Tentorium cerebelli

Back 6

— horizontal dural fold between cerebellum and cerebral hemispheres

Front 7

Falx cerebelli

Back 7

— along the vermis of the cerebellum

Front 8

Diaphragma sellae

Back 8

–covers pituitary gland in the sella turcica

Front 9

Dural sinus

Back 9

- formed between the periostal and meningeal layers of the dura
-drain blood from the brain back to the venous system

Front 10

What is the path of venous blood in the brain?

Back 10

-Inferior sagital, superior sagital, occipital and strait sinuses flow posteriorly into the confluence of sinuses then it flows out through the transverse sinus to the sigmoid sinus then out through the internal jugular vein
-from the cavernous sinus is made up of blood from ophthalmic, middle cerebral, and sphenoparietal sinus this drains out from the superior petrosal (dumps into the sigmoid) or inferior petrosal (dumps directly into the internal jug vein)

Front 11

What nerves in the dura matter are responsible for stretch headaches?

Back 11

-the trigeminal nerve responds to stimuli from superior to the cerebelli tentorum which feels like pain in the head
-the Vagus/greater occipital nerve responds to stimuli from inferior to the cerebelli tentorum which causes a referred pain to the back of the neck

Front 12

Headaches relation to dura matter

Back 12

- the brain itself is insensitive to pain
-Meningeal headache - stretch of dura due to variety of conditions
-Migrane headache - again stretch dura, but due specifically to increased arterial supply

Front 13

What arteries supply blood to the dura?

Back 13

-middle meningeal: largest and most lateral. clincally the most important. deep to the pterion (temple) and is injured with blows to the head
-ophthalmic: anterior dura
occipital and vertebral: posterior dura

Front 14

Arachnoid matter

Back 14

-middle layer with web like extensions called trebeculae that attach to pia matter
-space btwn arachnoid and dura is the subdural space
-subarachnoid cisterns
-arachnoid villi and granulations

Front 15

subarachnoid cisterns

Back 15

-formed by spans of arachnoid matter across sulci
-create pockets for CSF and BV

Front 16

arachnoid villi and granulations

Back 16

protrude into the dural sinuses and permit CSF reabsorption

Front 17

Pia matter

Back 17

- delicate layer of vascularized tissue that clings to the brain
-abutes layer of astrocytes end-feet at the surface of the CNS

Front 18

Blood brain barrier

Back 18

anatomical and physiological barrier that controls mvt of extracellular fluid from general body spaces to the CSF. there are regions where there are holes in the blood brain barriers in the hypothalmus and the pituitary and pineal gland

Front 19

How is the blood brain barrier formed?

Back 19

mainly formed by pia matter and the tight junctions btwn adjacent cells (astrocytes and endothelium)

Front 20

spinal dura

Back 20

-only one layer in the spinal cord (it's the meningeal dura that continues)
-does not attach to bone
-epidural (btwn skull and dura) space filled with adipose and venous plexus

Front 21

spinal arachnoid

Back 21

continuous with cranial

Front 22

spinal pia

Back 22

-continuous with cranial
- attached to arachnoid and thru dura via denticulate ligaments
-ends at the filim terminalae

Front 23

filum terminalae

Back 23

end of pia matter with an attachement to the dural sheath which attaches to the sacrum

Front 24

lumbar cistern

Back 24

subarachnoid space in the region of spinal nerves only- site of CSF sampling

Front 25

Intercranial hemorage

Back 25

- potential spaces in the meninges become filled.
-3 types: epidural, subdural and subarachnoid

Front 26

epidural hemorrhage

Back 26

-lens shaped
-Hematomas develop quickly and will be fatal due to confined space and arterial source (from meningeal artery)
-Usually due to blow to side of head

Front 27

subdural hemorrhage

Back 27

-crescent shaped
-Hematomas may develop slowly and neural deficiencies increase over time due to venous tear
-Tears usually in tributaries to superior sagittal sinus. typically there is a tearing of cerebral vein as it penetrates the arachnoid and enters dural sinus
-From rapid acceleration/deceleration – get shearing force due to brain lagging behind

Front 28

subarachnoid hemorrhage

Back 28

-btwn arachnoid and pia
-hematomas develop quickly and can be fatal
-debilitating headache/ unconsciousness (venous)
-due to sudden halt of head movement- damages the cortical veins draining into the sinuses