Head and neck anatomy may be important in the development of the BBB. Astrocytes may also be responsible for transporting ions (electrolytes) from the brain to the blood. Blood from the brain and neck flows from: (1) within the cranium via the internal jugular veins, a continuation of the sigmoid sinuses. The right and left external jugular veins drain from the parotid glands, facial muscles, scalp into the subclavian veins. The right and left vertebral veins drain the vertebrae and muscles into the right subclavian vein and into the superior vena cava, into the right atrium of the heart. The lymphatic system drains the
History of the location of the soul His medical anatomy is described through the use of Plato's corporeal ideals of the soul. The heart was the spirited, the liver the appetitive, and the brain the logical. Galen states in "On Respiration and the Arteries" "one must determine by dissection that the number and nature of the structures that connect the heart to the brain" and it was observed that when these nerves were cut in animals they would lose their voice and when veins were cut they would bleed, but retain their voice. Therefore the brain does not need the heart to feel or create sensations and