The inferior ganglion of the glossopharyngeal nerve (petrosal ganglion) is a sensory ganglion. Also an inferior petrosal sinus enters the sigmoid sinus near the jugular foramen. Preganglionic parasympathetic fibres exit the geniculate ganglion as the greater petrosal nerve. Each inferior petrosal sinus drains the cavernous sinus into the internal jugular vein. The greater petrosal, lesser palatine and zygomatic nerves all synapse here. The greater petrosal nerve carries parasympathetic preganglionic fibers from the facial nerve. The greater superficial petrosal nerve lies also underneath the ganglion. This plexus gives off the lesser petrosal nerve. The chorda tympani is less responsive to sucrose than is the greater superficial petrosal nerve. Note that a superior petrosal sinus enters the junction of the transverse and sigmoid sinuses. The nucleus of the lesser petrosal nerve is the inferior salivatory nucleus. The greater petrosal, carries soft palate taste signals to the facial nerve. The first is the greater petrosal nerve and the second is the chorda tympani.