<s>[INST] context: Internal jugular vein is the direct continuation of the sigmoid sinusThe sigmoid sinuses:They are two areas beneath the brain which allow blood to drain inferiorly from the posterior center of the head.They drain from the transverse sinuses and converge with the inferior petrosal sinuses to form the internal jugular veinEach sigmoid sinus begins beneath the temporal bone and follows a touous course to the jugular foramen, at which point the sinus becomes continuous with the internal jugular veinThe internal jugular vein:It collects the blood from the brain, from the superficial pas of the face, and from the neck.It is directly continuous with the transverse sinus, and begins in the posterior compament of the jugular foramen, at the base of the skull.The thoracic duct on the left side and the right lymphatic duct on the right side open into the angle of union of the internal jugular and subclan veins.The external jugular vein:It is formed by the junction of the posterior division of the posterior facial with the posterior auricular vein.It commences in the substance of the parotid gland, on a level with the angle of the mandible.The anterior jugular vein:It begins near the hyoid bone by the confluence of several superficial veins from the submaxillary region.It descends between the median line and the anterior border of the Sternocleidomastoideus, and, at the lower pa of the neck, passes beneath that muscle to open into the termination of the external jugular, or, in some instances, into the subclan vein [/INST] question: Internal jugular vein is the continuation of which of the following sinus | options: A: Cavernous sinus B: Sigmoid sinus C: Inferior petrosal sinus D: Superior petrosal sinus | answer: B </s>