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Pachymeninx (thick)
Dura mater
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Leptomeninges (slender, thin)
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LV
- telenceph
- Frontal, Occipital, Temperal horn meet at the trigone
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3rd V
- dienceph
- f or Monro to 3rd
-
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CSF
- 500 cc/day
- (25cc V's, 125 subarach-->3-4 times/day)
- chroid plexus: actively secretes
- reabsorbed into BS thru dura venous sinus
- arachnoid villi- act as 1-way valve between subarachnid space dural venous sinuses
- Lumbar pucture- L4-L5
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Ependyma
- ependyma- epith of V's
- CP and ependyma continuous epith at tela choroidea
-
CP: Histology
- TJ in epithelium
- fenestrated capillaries
- cleared into cap, CSF and other material secreted out of caps
- no CP in aqueduct (too narrow), but yes, in V's
-
BBB
- 1.TJ between EC
- 2. astrocytes ensheath CNS capillaries
- Permeable: glucose, aa, lactate, lipid-sol components (unocnj bilirubin), DOPA
- Impermeable: large prot (albmin), bound prot's (conj bilirubin), polar molecules (catechol), Ab
-
Normally lack of BBB- monitor
- Post pit (neurohypophysis)
- Pineal gland
- Cicumventricular: lamina terminalis, subforniceal organ, median eminence of hypothal, area postrema
-
Break down of BBB
- Injury of brain caps
- Inflammation-- maybe good to allow Ab in
- Proliferation of new caps lacking TJ healing, timors)
-
BCB
Dependent on TJ of epith of CP (unlike BBB that dep on TJ of EC cuz CP caps are fenestrated)
- Perm: water, gas, lipid-sol, micronutrients, small pept
- Imperm: proteins, small polaar molecules
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BNB
- Similar to BBB
- TJ of EC of endoneurial cap in PNS
- Prevents organisms/large molecules to enter nerves
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