Blood supply of CNS Flashcards
Describe cerebral circulation
Internal carotid artery system: supplies most of cerebrum (anterior supply)
Vertebrobasilar artery system: supplies brainstem, cerebellum, and spinal cord. Posterior circulation.
Draw blood supply of CNS and circle of willis.
Vertebral arteries give off posterior inferior cerebellar arteries (PICA), fuse to become basilar, give off anterior inferior cerebellar arteries (AICA), superior cerebellar arteries, and end as posterior cerebral arteries. Circle of willis connects posterior and anterior circulation. Internal carotid gives off middle cerebral arteries and anterior cerebral arteries. Posterior communicating arteries connect posterior cerebral arteries to internal carotid/middle cerebral arteries. Anterior communicating connects the two anterior cerebral arteries.
What arteries supply deep cerebral structures?
Small perforating (or ganglionic) arteries coming off of arteries near the base of the brain.
What are perforated substances?
Visible entry points of perforating arteries on base of the brain.
Describe cerebral veins
Valveless. Superficial and deep veins.
Describe superficial vein path
Superficial veins -> superior sagittal sinus -> confluence of sinuses -> transverse sinus
Describe deep vein path
Deep veins -> internal cerebral vein -> Great vein (of Galen) -> straight sinus -> confluence of sinuses -> transverse sinus.
Describe mechanism of regulation of cerebral blood flow
Autoregulation: smooth muscle and arterial mediated.
Metabolic: glutamate->vasodilation
List brain barriers
Blood brain barrier, blood-CSF barrier, arachnoid barrier.
Describe function and components of BBB
Restricts ionic/fluid movements, supplies essential nutrients, mediates efflux of waste or toxic products. Capillary endothelial cells, pericytes, astrocytes, neuronal processes.
Name the various types of cranial bleeds.
Epidural, subdural, subarachnoid, intracerebral, and intraventricular.
How to distinguish between CT and MRI?
On CT, bone/calcium/blood=white.
