Lab 4: Blood Supply/CSF Flashcards
Vertebral Arteries
Located on the ventral medulla; have spinal branches that include
Anterior spinal branches (anterior spinal artery)
Posterior spinal arteries
Anterior Spinal Branches Join to make Anterior Spinal Artery
Travels in the ventral median fissure
Posterior Spinal Arteries
Are difficult to find; descend near the attachments of the dorsal roots; often branch from the posterior inferior cerebellar Artery
Segmental Artery Branches
Vertebral, intercostal, lumbar and lateral sacral
Further subdivided into:
Anterior and posterior radicular arteries: that mainly supply the nerve roots, dorsal root ganglia and dura
Medullary arteries: branch from 8-10 of the segmental arteries and connect to the anterior and posterior spinal arteries to produce an arterial vasocorona that surrounds and supplies spinal cord
Artery of Adamkiewicz: a very large medullary artery, often branching from a lower intercostal or upper lumbar artery,m that makes a major contribution to the supply of the lower thoracic and upper lumbar spinal cord
Venous Return from the Spinal Cord
Blood from the spinal cord drains into 3 longitudinal systems: (Anastomose extensively) -spinal cord plexus -epidural (internal vertebral plexus) -external vertebral plexus
Vertebral-basilar system (posterior circulation)
Supplies:
Spinal cord, brainstem, cerebellum and parts of the medial forebrain
Internal Carotid System (anterior circulation)
Supplies most of the forebrain (telencephalon and diencephalon)
(Arterial Supply to the Brainstem) From the Vertebral Arteries
Anterior and posterior spinal arteries (posterior can originate from PICA)
Posterior inferior cerebellar arteries (PICA): long circumferential arteries
(Arterial Supply to the Brainstem) From the Basilar Artery
Paramedian pontine arteries (paramedian branches of basilar artery)
Short circumferential pontine arteries (short circumferential branches)
Anterior Inferior Cerebellar Arteries (AICA): long circumferential arteries
Superior cerebellar arteries (long circumferential arteries)
Posterior Cerebral Arteries (terminal branches)
Branches of the Internal Carotid Artery
Anterior cerebral artery
Middle cerebral artery
Great Arterial Circle of Willis
Variable, large vessel communication on the base of the brain, encircling the optic chiasm and mammillary bodies of the hypothalamus.
Communicating branches allow rerouting of blood between the anterior and posterior circulations (via posterior communicating arteries) and between left and right circulations (via an anterior communicating artery)
Frequently permits rerouting of blood around slowly-developing conclusions of the large vessels that supply the brain
Contributions of the Cerebral Arterial Circle (of Willis)
Posterior Cerebral Arteries Anterior Cerebral Arteries Middle Cerebral Arteries Posterior Communicating Arteries Anterior Communicating Artery
Middle Cerebral Artery Branches (in the lateral fissure)
Cortical branches that supply the lateral cortex
Anterior Cerebral Artery (longitudinal fissure)
Has cortical branches that supply the medial frontal and parietal cortex
Posterior Cerebral Artery
Winds around the midbrain; has cortical branches that supply the medial occipital and medial and inferior temporal cortex
Mid/Rostral Medulla Blood Supply
Paramedian: anterior spinal arteries
Anterolateral: Short circumferential branches of the vertebral artery
Posterolateral: posterior spinal arteries (caudally) as you move rostrally it becomes the long circumferential branches of PICA
Caudal Pons Blood Supply
Paramedian: Paramedian branches of the basilar artery
Anterolateral: short circumferential branches of the basilar artery
Posterolateral: long circumferential branches of the basilar Artery caudally and the anterior inferior cerebellar artery as you move rostrally
Rostral Midbrain Blood Supply
Paramedian: paramedian branches of the basilar artery bifurcation
Anterolateral: short circumferential branches of the posterior cerebral artery
Posterolateral: long circumferential branches of the posterior cerebral artery and some of the superior cerebellar artery
Venous Drainage of Spinal Cord and Brain
The veins that drain the brain run their course independent of the arteries. They anastomose freely and form four interconnected systems Intra-axial veins Superficial cerebral Veins Deep cerebral veins Dural Venous Sinuses
Intro-axial Veins
Collect capillary blood and travel in brain tissue; they drain into a serious of mostly superficial veins
Superficial Cerebral Veins
Drain the intra-axial veins of the cerebral cortex and underlying white matter
Traverse the SAS in cerebral sulci, superficial to cerebral arteries
Penetrate the arachnoid, the subdural space (as bridging veins) and the dura to drain into nearby dura venous sinuses
“Bridging” veins can tear in shear force injury and cause subdural hemorrhage
Deep Cerebral Veins
Drain deep structures
Dural Venous Sinuses
Are venous channels that are embedded in layers of cranial dura
Drain the superficial and deep cerebral veins
Eventually drain into the internal jugular vein
Lateral Ventricle Components
Anterior horn Body Atrium Posterior horn Inferior horn
