CSF and Meninges Flashcards Preview

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Flashcards in CSF and Meninges Deck (40):
1

What is the main function of the meninges?

PROTECTION

2

What are the two layers of the dura mater?

Periosteal layer
inner meningeal layer

stuck together and very tightly tacked onto the skull

3

Special places where two dura layers come apart to form?

sinuses

4

What forms falx and tentorium dural infoldings?

meningeal layer

5

Which mater layer is trabecular?

Arachnoid! Contains projections and space that contains CSF

6

What is the pia layer consisted of?

Single layer of cells that wrap around entire brain...single of layer of epithelium

7

Where does the dural layers end?

periosteal ends at foramen magnum

meningeal continues to go down with spinal cords

8

Spinal cord ends? Dural sac?

Spinal ends at L1
dural sac ends around S2 (contains nerves that have come out of spinal cord but haven't exited vertebral column...cauda equina)

9

What does the epidural space along vertebrae contain and why is it importance?

Nerves leaving spinal cord, important for placement of epidural anesthesia and good place for spinal tap

10

Names and number of ventricles?

Lushka (2 lateral)
megendi (1 medial)

all 3 communicate with cisterna magna

11

Functions of CSF

- provides buoyancy to brain (less traction on nerves and vessels)
- dampens effects of trauma
- provides stable ionic environment
- removes metabolites from brainn extracellular fluid

12

composition of CSF

150 cc present, about 500 cc/day made,

clear low viscosity

very little protein

less glucose than serum

acellular


THINK CLEAR AND LOW, like water...can get headaches of too much drained after LP

13

What makes the CSF?

Choroid plexus. Little stringy fronds of vascularized tissue that are present in ventricles Leaky fenestrated capillaries that uses CARBONIC ANHYDRASE for production...actively transports ions

14

What is the blood CSF barrier?

Tight junctioned epithelium that filters large molcules like proteins

15

Flow of CSF starting from lateral ventricles

lateral ventricles > foramen of Monro (2) > 3rd ventricle > cerebral aqueduct > 4th ventricle > magendie and luschka (2) > cisterna magna > cortex, spinal canal > along nerve sleeves > arachnoid villi granulations > superior saggital sinus >jugular veins

16

What moves CSF?

ependymal cilia

17

target of LP

L3/L4/L5

18

Path of needle in LP?

Skin > subcutaneous > supraspinous ligament > ligamentum flavum (stop here for epidural anesthesia) > dura/arachnoid (stop here for CSF drainage)

19

Meningitis?

Inflammation or infection of meninges

20

What is aseptic meningetis?

Non-bacterial/non neutrophilic meningitis

21

Signs of meningitis?

Headache, fever, neck stiffness, photophobia, encephalopathy

22

How to Dx meningitis?

LP to analyze CSF and see a high WBC count and protein in CSF

23

Features of meningiomas?

Benign, slow growing, asymptomatic, generally good prognosis

24

Types of meningeal bleeds

epidural, subdural, subarachnoid

25

Features of epidural hematoma

bleed in between skull and periosteal layer of dura. Consequence of traumatic rupture of MENINGEAL ARTERIES...acute

26

Features of subdural bleed

Occur under dura, outside arachnoid. consequence of trauma to bridging VEINS (but can be chronic also , can be acute or chronic

27

Features of subarachnoid bleeds?

occurs deeper in brain substance, can happen traumatically but usually due to ANEURYSMAL rupture of cerebral arteries. (Associated with thunderclap headache), acute

28

What is hydrocephalus?

Obstructive process that results in dilation of CSF spaces (dilated ventricles or anywhere where CSF travels)

Water. Head. Get it.

29

Communicating vs non-communicating hydrocephalus?

communicating - all places carrying CSF are still normally connected, but have problem draining (i.e. scarring of arachnoid villi)

non communicating - doesn't communicate with rest of CSF
I.e. scarring of aqueduct while ventricles keep making CSF

30

What can increase intracranial pressure?

Diffuse, focal edema (brain)
hydrocephalus, meningitis (CSF)
blood, venous clot (blood)
extra stuff (tumor or abess)

31

Signs of increased intracranial pressure

headache, vomiting, bradycardia and hypertension, papilledma

32

What does elevated protein in CSF indicate?

infection or inflammation, Guillan Barre syndrome, MS

33

What do elevated WBCs and low glucose indicate?

infection, inflammatoin, neutrophils in bacterial meningitis, aseptic process

34

What do elevated RBCs indicate?

Subarachnoid hemorrhage, hemorrhagic meningitis

35

Normal color of CSF?

clear

36

Xanthochromia

yellow CSF, old blood (Hb turned into bilirubin)

37

Functions of blood-brain-barrier (BBB)

- keep plasma toxins out of brain
- block tiny oscillations of plasma ions
- keep plasma proteins and growth factors out
- keep NTs from going in or out of brain

GANDALF WITH STAFF YOU SHALL NOT PASS

38

What forms BBB?

unique capillaries. Tight junctions in endothelial cell, processes of ASTROCYTES, capillary basement membrane

39

What parts of brain lack BBB?

Area postrema - needs to sense toxins so you can vomit

OVLT - needs to sense ions and osmolar changes in order to influence ADH production

40

What determines what passes through BBB?

Lipid solubility (hydrophobicity)...

if too fast, carrier mediated transport

if too slow, albumin bound