→ Entry/ Exit and important structure: - From infratemporal fossa via pterygomaxillary fissure: maxillary a. - From the middle cranial fosssa - via the foramen rotundum: V2 - via pterygoid canal: greater petrosal + deep petrosal n. - From the orbit via the inferior orbital fissure: infraorbital and zygomatic n. - From the oral cavity through the palatine canal: greater and lesser palatine n. and vessels **Remember that these branches also carry sympathetics and parasympathetics coming in by the nerve of the pterygoid canal.** Preganglionic **parasympathetic fibers** originate in the brainstem with CN VII. At the geniculate ganglion they form the **greater petrosal nerve** that runs anteromedially.  As the greater petrosal nerve crosses the internal carotid artery, it is joined by the **deep petrosal nerve**, which consists of postganglionic **sympathetic fibers** that entered the cranial cavity on the surface of the internal carotid.  The greater and deep petrosal nerves continue together through the pterygoid canal. This **nerve of the pterygoid canal** enters the back of the pterygopalatine fossa and the parasympathetic fibers synapse in the pterygopalatine ganglion. Postganglionic cells in the ganglion send their axons into the nasal, palatine and pharyngeal branches of CN V2 to get to the mucous membranes of the nasal cavity. The sympathetic fibers from the deep petrosal nerve pass through the ganglion and into the same branches. Some of the postganglionic parasympathetic fibers follow the branches of V2 that suspend the ganglion to reach the zygomatic and zygomaticotemporal branches and finally the lacrimal branch of V1 to get to the lacrimal gland. The parasympathetic fibers stimulate vasodilation and secretion of tears. https://wisc.pb.unizin.org/paanatomyunit3/chapter/dissection-18-nasal-cavity-and-pterygopalatine-fossa/ ![[Pasted image 20250208162102.png]] ![[Pasted image 20250208162105.png]] ![[Pasted image 20250208164446.png]] ![[Pasted image 20250208165115.png]] ![[Pasted image 20250208164917.png]]