 First of all let's talk about the parotid region. So what are the boundaries of the parotid region? Anteriorly, we have the meseter muscle. Under that we have the ramus of the mandible. And deep to that is the medial teregoid. Posteriorly, we cannot see it here. We have the mastoid process. And to that we have attached the posterior belly of digastric. Deep, we also cannot see the stellar process with the muscles attached to it, three of them. Posteriorly, we have the external rimeatus. And superiorly we have the zygomatic arch. So this whole region constitutes the parotid region. Parotid sheath or the parotidomethetric fascia is derived from the investing layer of deep cervical fascia. But here it becomes especially thick and we have retained part of it here and we can see how thick it is. It is an extremely tough fascia which completely invests the parotid gland. It also covers the meseter muscle and we have retained a little bit of that here also. It also covers a part of the sternocular mastoid muscle here. So we have completely separated out this parotidomethetric sheath. Deep inside, this one gives an extension which is referred to as a stylo-mandibular ligament. Which extends from the styloid process to the angle of the mandible. Parotidomethetric sheath is supplied by the great auricular nerve which carries pain fibers. Because of the tightness of the sheath, mumps, parotides or inflammation or abscess is very painful. Now let's come to the duct. This is the parotid duct or the stensus duct. And we can see it arises from the anterior border of the parotid gland. It runs on the surface of the meseter muscle and then it dips inside and it pierces through this muscle here. This is the buccinator muscle and it opens opposite the crown of the upper second molar tooth. This location is important because we use that as a landmark for cannulating the parotid duct while doing a xylography. The superficial part of the parotid gland as we can see is flat. And the deep part of the gland which we cannot see is more wedge shape because it is in relation to the styloid process. Once we reflect the superficial part of the parotid gland, we can see the structures which are deep inside. In order to understand the structures which are deep inside, let's start from outside first. This is the superficial temporal vein which runs in the superficial temporal fascia. This is the superficial temporal artery, the tortuous one, dividing it to a frontal and parietal branch. And this is the auricular temporal nerve. So having seen these, now let's come to the structures deep inside. We see this vein here. This is the retromandibular vein. How is this retromandibular vein formed? We can clearly see one branch here. This is the superficial temporal vein and we can see yet another branch here coming from the intratemporal fascia. This is the maxillary vein. So superficial temporal vein and maxillary vein, they unite to form the retromandibular vein. And the retromandibular vein will then continue down and it will meet with other structures to form the external jugular vein. So this is one important structure which is inside the parotid gland. The next structure that we see here, I have picked up this structure here. This is the external parotid artery. The external parotid artery inside the parotid gland, it divides into a large terminal division which we cannot see. And that is called the maxillary artery which enters into the intratemporal fascia. And it divides into a smaller terminal division which is this one here. This is the superficial temporal artery. And this superficial temporal artery then runs in front of the tragus of the ear and runs in the superficial temporal fascia. And we can feel the pulsation of the superficial temporal artery in front of the tragus of the ear. The next structure which runs through the parotid gland is this which I mentioned is the auricular temporal nerve. The auricular temporal nerve is a branch of the mandibular nerve. It gives sensation to the skin of the temporal region. It also carries most ganglionic secretory fibres to the parotid gland which came from the aute ganglion. And last but definitely not the least, this is the structure which I picked up here inside the parotid gland. This is the facial nerve. The facial nerve as it emerges from the stalomastoid foramen, it winds around the neck of the mandible. And it is situated lateral to the retromandibular vein. And it ramifies inside the parotid gland where it forms a plexus known as the pesancerinas. And after that it supplies the muscles of facial expression by means of five branches. And incidentally we can see a branch of the facial nerve coming out here through the parotid gland. And we can see it, another branch of the facial nerve coming down here which is supplying the pletisma muscle. So we notice that the retromandibular vein is medial to the facial nerve. So therefore combining the retromandibular vein and the facial nerve together. This is referred to as the, it's a surgical plane called the fasiovenous plane of PT. And this helps to divide the gland into a superficial part and a deep part. And this enables us to do what is known as superficial parotidectomy. So that brings me to some other clinical correlations pertaining to the parotid gland. If you notice that the lobule of the ear is very closely related to the parotid gland. So if in any patient we see if the lobule is elevated like this, it indicates a parotid swelling. So this is a clinical sign. Patients who have got diabetes, they also get nonspecific enlargement of the parotid gland. Then also the lobule of the ear is elevated. A very common tumor of the parotid gland is called pleomorphic adenoma which generally occurs in the superficial part. In which case we will have to do a superficial parotidectomy. If a patient gets a stab injury of the parotid region, the auriculotemporal nerve may be injured. And during the regeneration process, it can establish communication with the great auriculot nerve. And therefore when the patient eats, there will be a patch of sweat here. And that is called castatory sweating or the auriculotemporal syndrome or the phrase syndrome. Parotid duct stones, parotid strictures can also occur. And the best way to diagnose it is by cannulating the parotid duct through the opening opposite the upper second molar tooth. Talking about the parotid duct, we can see portion of the parotid gland tissue here. Accessory parotid in relation to the duct of the parotid. This is not abnormal. This accessory parotid tissue is referred to as social parotidis. This is something which we notice here. So that's all for now. Thank you very much for watching. Dr. Sanjeev Sanyal signing out.