1. Vasculature, csf, and meninges

2. objectives
Explain how oxygen is delivered to brain tissue, how the brain is suspended in liquid, and how fluid flows between the systems
Identify disorders of vascular supply, formation and pressure imbalances from descriptions of the problem

3. meninges Dura – thick fascia, 2 layers
Outer layer attached to skull
Inner layer attached to arachnoid, continuous with spinal dura
Sinuses formed by spaces between dural layers
Arachnoid – Thin, flexible connective tissue
Attached to pia with arachnoid trabeculae
Pia – thinnest layer
Fused to surface of brain
Follows gyri and sulci
meninges
Veins and arteries run in subarachnoid space – subarachnoid hemorrhages
Meningeal arteries run in epidural – epidural hematomas
Veins cross the subdural space to connect veins with sinuses – subdural hematomas

4. Sinuses vs cisterns Sinuses – within dura (between layers)
Cisterns – subarachnoid space
Suprasellar
Quadrigeminal
Infrapontine
Cisterna magna

5. Falx cerebri and tentorium cerebelli
Folds of the inner layer of dura mater separating the cerebral hemispheres and the cerebrum from the cerebellum
Outer layer of dura
Inner layer of dura
Left hemisphere
Right hemisphere
FALX CEREBRI

8. Video for visuals only https://www.youtube.com/watch?v=J2oVjn2ALLE
Craniosacral movement is BS, but this video is useful for the visuals

9. Veins and sinuses SSS ISS Straight Confluence Transverse Sup petrosal
Inf petrosal
Sigmoid
Internal jugular vein

10. CSF Drainage
Csf drains from subarachnoid space directly to the sinuses
Arachnoid villi/granulations

11. ventricles 1&2 – aka lateral ventricles, in hemispheres
Interventricular foramen (of Monroe)
3 – in diencephalon
Cerebral aqueduct
4 – in pons/medulla/cerebellum
2 lateral & 1 medial foramen to subarachnoid space

12. Lateral ventricles Anterior horn Body (splenium) Atrium Posterior horn
Inferior horn

16. Circle of willis
Entering circle: basilar artery, internal carotid arteries
Within circle only: posterior communicating, anterior communicating
Exiting circle: Posterior cerebral, middle cerebral, anterior cerebral

17. Videos for your reference

18. Cerebral arteries
Each cerebral artery is broken into segments to understand locations of strokes more easily
Aca has 5 segments
Mca has 4 segments
Pca has 4 segments

19. Aca (pg 29 of haines) A1 – portion of aca within the circle of willis
No major branches
A2 – portion of aca between anterior communicating and bifurcation of pericallosal and callosomarginal.*
Orbital and frontopolar branches
A3 – pericallosal artery
A4 and a5 – small terminal branches of aca
*callosomarginal artery exists in about 60% of the population

20. Mca (pg 39 of haines) M1 – portion of mca before bifurcation
Supplies basal ganglia, choroid plexus of lateral ventricles
M2 – portions of mca coursing over insula
M3 – portions of mca coursing along undersides (deep surfaces) of parietal and temporal lobes
M4 – branches of mca supplying lateral surface of cortex:
Orbitofrontal, prerolandic, rolandic, anterior and posterior parietal branches, angular, anterior and posterior temporal branches.

21. Pca (pg 21 of haines) P1 – portion of pca within circle of willis
Supplies midbrain, thalamus, choroid plexus of lateral and 3rd ventricles
P2 – portion of pca outside of circle, before major branches
P3 – anterior temporal, posterior temporal, and continuation of pca
P4 – parieto-occipital, calcarine

23. Vertebrobasilar system
Blood supply to the brainstem and cerebellum!
Inferior to superior:
Vertebral A
Posterior inferior cerebellar A
Anterior spinal A
Basilar A (only one not paired)
Anterior inferior cerebellar A
Pontine A
Superior cerebellar
pca

24. Disorders Hematomas (subdural and epidural) Hydrocephalus
Intracranial pressure
Herniations
Uncal
Central
Tonsillar
Strokes (cerebrovascular accidents)
Infarction vs hemorrhage
Transient ischemic attack (TIA)
Completed stroke
Progressive stroke
Aneurysms
Arteriovenous malformations

25. Disorder identification
Blood from a vein pools in the subdural space
Blood from an artery pools in the subarachnoid space
Blood from an artery pools in the epidural space
An embolus occludes the Mca with symptoms lasting less than 24 hours
An embolus occludes the aca with symptoms lasting longer than 24 hours