 Everybody, Dr. Sange Sangal, Professor Department Chair, in this video demonstration I shall demonstrate the most important neurovascular structures which are located specifically in the dotted triangle of the neck. This nerve which is there in front of us, this is the spinal accessory nerve. This comes out through the jugular foramen, but this is the only nerve in this region which travels laterally and it supplies the sternocleomastoid, goes through the lateral cervical region and it supplies the trapezius. So this is the spinal accessory nerve. The next nerve that we can see here is this. This is the hypoglossal nerve and we can see the hypoglossal nerve crosses in front of the loop of the lingual artery. It also crosses the front of the bifurcation of the internal and external carotid artery and then it enters the tongue by going superficial to the hyoglossus but deep to the mylohyoid. This has got an intimate relationship with the lingual artery and both of them go to the tongue. The only difference being the lingual artery enters the tongue deep to the hyoglossus while the hypoglossal nerve enters the tongue superficial to the hyoglossus. The hypoglossal nerve CN12 exits the cranial cavity through the hypoglossal canal which is on the natural margin of the foremen magnum. And just to bring you up to speed, this branch that we see here, this is a branch from the superior limb from the Ancer Cervicalis which is derived from the loop of C1 C2 and it is also referred to as descending hypoglossi which supplies the geniohyoid and thyrohyoid muscle. This branch is actually strictly speaking not a part of the hypoglossal nerve. It is just accompanying the hypoglossal nerve. The next nerve that we can see is this nerve which I have picked up here. This is the glossopharyngeal nerves. This also exits the cranial cavity through the jugular foremen. This runs between the bifurcation of the internal and the external carotid artery and we can see the other end of the glossopharyngeal nerve on this side and it enters the pharynx with the stylohyoid ligament by piercing between the superior pharyngeal constrictor and the middle pharyngeal constrictor. This supplies the stylopharyngeal muscle. The rest of the muscles the pharynx are supplied by the vagus nerve. When the glossopharyngeal nerve is running between the bifurcation of the carotid into an internal and external carotid, it gives off the carotid sinus branch and the carotid sinus branch then supplies the carotid sinus which is a dilatation at the beginning of the internal carotid artery and it also gives a branch to the carotid body which is also located in this region. They mediate what is known as the carotid sinus reflex and the carotid body reflex. The carotid sinus is a paroreceptor, the carotid body is a peripheral chemoreceptor. The first branch of the glossopharyngeal nerve which we cannot see because it is situated right under the base of the skull and that is the tympanic branch. The tympanic branch carries the parasympathetic secretive motor fibers which enter the tympanic cavity and forms the tympanic plexus and from there the lesapeutrocell nerve comes out and it supplies the secretive motor fibers through the otic ganglion to the parotid gland and that brings me to the last but not the least nerve which is running in the carotid sheath and that is the this nerve which i have picked up. This is the vagus nerve. This vagus nerve runs on the posterior aspect of the carotid sheath behind the internal jugular vein and the carotid artery and this runs down and as it runs down in the neck we can see it is crossing in front of the right subclavian artery and as it crosses in front of the right subclavian artery it gives off a branch which loops under the subclavian artery and then climbs up here. This is the recurrent laryngeal nerve on the right side. Here see the left vagus nerve and here we can see that the distribution of the recurrent laryngeal nerve on the left side is considerably different from the right side. The vagus nerve gives a branch which is looping under the arch of aorta and this is the left recurrent laryngeal nerve. This loops under the arch of aorta lateral to the ligamentum arteriosum and then it climbs up. This recurrent laryngeal nerve is an important supply of the larynx and it's got a very important relationship with the carot gland. This is the distribution and the course of the recurrent laryngeal nerve on both the sides. So these are the various cranial nerves that we can see in this dissection. Thank you very much for watching ladies and gentlemen. If you have any questions or comments please put them in the comment section below. Dr. Sajja Sanyal signing out. Have a nice day. Guys thank you so much for watching. Make sure you like this video. Make sure you click to subscribe.