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
Internal pudendal veins pudendal veins, but ends mainly in the pudendal plexus. Internal pudendal veins The internal pudendal veins (internal pudic veins) are a set of veins in the pelvis. They are the venae comitantes of the internal pudendal artery. They begin in the deep veins of the vulva and of the penis, issuing from the bulb of the vestibule and the bulb of the penis, respectively. They accompany the internal pudendal artery, and unite to form a single vessel, which ends in the internal iliac vein. They receive the veins from the urethral bulb, the perineal and inferior hemorrhoidal veins. The deep