The document discusses the two systems that provide blood flow to the brain - the carotid system and the vertebrobasilar system. It also mentions the circle of Willis and its role in cerebral irrigation. Images show a coronal and horizontal cross-section of the brain as well as examples of arteriovenous malformations, abnormal connections between arteries and veins that can hemorrhage and cause bleeding in the brain.

1. STROKE

2. Irrigación cerebral 2 sistemas: Carotideo (Superior). Vertebrobasilar (Posterior). polígono de Willis Cerebrales anteriores (2). Comunicante anterior. Comunicantes posteriores (2). Carótida interna. Cerebral posterior.

6. Corte Coronal Corte Horizontal

9. Vascular Malformation (Arterio-venous Malformation) A-V malformation. Surface of a brain with numerous draining veins.

10. Vascular Malformation (Arterio-venous Malformation) A-V malformation in full development.

11. Vascular Malformation (Arterio-venous Malformation) There is a large hemorrhage which originated in the malformation and extended frontally.