The Brain

Meninges are the 3 wrappings around the brain. 1. The outer most layer is the Dura Mater that consists of major blood vessels. The Dura Mater is 2 layers thick around the brain, inner called the Meningeal and outer called the Periosteal, and 1 layer thick around the spinal cord. 2. Arachnoid Mater is the middle most layer there are no blood vessels in this layer, CSF is located here. 3. Pia Mater is the inner most layer that contains capillary network. We are also working on the Circulatory Pathways. Venous Pathway or Venous drainage and the Arterial Pathway. Venous drainage, CSF drains from the Superior Sagittal Sinus through the Confluence of Sinuses (point where straight sinus, s sagittal sinus, & occiptal sinus meet) then to the transverse sinuses on to the sigmoid sinuses and into the 2 internal jugular veins. Arterial Pathway, oxygen rich blood from the left side of the heart is carried to the left Atrium it then reaches the left Ventricle via the Bicuspid valve, from the left Ventricle it travels through the Semilunas valve (Aortic valve) into the Ascending Aorta to the Aortic Arch. In the Aortic Arch it goes to the right Subclavian artery and right Common Carotid artery via the Brachiocephalic, the left Common Caroid artery which feeds the Circle of Willis, and to the left Subclavian artery. It also travels out the descending Aorta to suppply blood to the Thoracic and Abdomen.
We receive many patients that have suffered strokes and or blood clots to areas of their bodies. DVT's (deep vein thrombosis) are common with our elderly. I was once involved with a code on a patient that was having a Pulmonary Emblosism, I knew it was a blood clot that had traveled to the lungs but I did not understand it completely until I started to get more in detail with this weeks study of the Circulatory pathway of blood and CSF. That same patient also had a history of strokes.