 Okay, so this is a demonstration of the intra-temporal fossa. In order to reach the intra-temporal fossa, this is the right side of the cadaver. We had to do the following procedures. First, we had to remove the parotid gland. So this is the superficial part of the parotid gland, which we have removed, and this is the cut section of the stensin duct. Next we had to do was, we had to remove the zygomatic arch. The zygomatic arch was standing from here to here. This was the location of the zygomatic arch. Then we had to reflect the temporalis muscle, because the temporalis muscle is inserted into the coronoid process. So this is the temporalis muscle. Next we had to reflect the meseter muscle, which was attached to the angle of the mandible. And then we had to cut the ramus of the mandible here. And once we did all that, then we reached the intra-temporal fossa. So this is the intra-temporal fossa in front of us with all its contents. So let's start off with the boundaries of the intra-temporal fossa. Anteriorly, the intra-temporal fossa is demarcated by the posterior surface of the maxilla. Pustially, it is demarcated by three structures. The mastoid process, the stalate process, which we cannot see because they're covered by muscles, and the tippanic plate of temporal bone. So all those things are located where my finger is pointing. Immediately, it is demarcated by the lateral teregoid plate, which is covered by these muscles. And laterally, it is demarcated by the ramus of the mandible, which has been removed, as I mentioned just now. Superiorly, it is bounded by the intra-temporal surface of the greater ring of sphenoid. And inferior limit of the intra-temporal fossa is where the medial teregoid gets inserted onto the inner surface of the angle of the mandible. So this is the full limit of the intra-temporal fossa. The intra-temporal fossa contains muscles, arteries, veins, nerves. So the way I teach people is the intra-temporal fossa contains the mandibular nerve and the maxillary artery. So therefore, it is IT-MAMA. That's one of the most important contents, which I shall describe just now. So let's start off with the contents of the intra-temporal fossa, and we will start with the muscles. The two most important muscles are these. The lateral teregoid and the medial teregoid. Let's start off with the lateral teregoid. The lateral teregoid has got two parts. We can see a superior head and an inferior head. Both of them together make a triangular shaped muscle. The superior head, it takes attachment from the intra-temporal crest of the sphenoid, and it gets inserted onto the articular cartilage of the temporal mandibular joint here. The inferior head, it takes attachment from the lateral surface of the lateral teregoid plate, and it gets inserted onto the teregoid phobia, which has been removed on the neck of the mandible. So this is the triangular shaped muscle. The action of the lateral teregoid is to... This is the only important muscle abastigation which lowers the mandible, therefore it opens the jaw. It also causes side to side movement of the jaw that is chewing movements, lateral chewing movements, contralaterally. That means the right side will act to turn the jaw left and vice versa. So that is about the lateral teregoid muscle. It is a triangular shaped muscle. Now let's come to the medial teregoid muscle. The medial teregoid muscle is quadrangular shaped, and this has also got a superior head, some books call it the deep head, and an inferior head also called the superficial head. Let's take the superior head. The superior head takes attachment from the medial surface of the lateral teregoid plate, and the inferior head takes attachment from the posterior surface of the maxilla. And both of them become a quadrangular shaped muscle and they descend down and they get attached to where my finger is pointing on the teregoid tuberosity on the inner surface of the angle of the mandible. The medial teregoid is the mirror muscle of the masseter muscle. So therefore if there is a fracture of the mandible at the angle, the fracture fragments are self-splinted by the masseter at the medial teregoid. The medial teregoid is responsible for closure of the jaw, and it is also responsible for small side to side chewing movements, contralateral. So that's about the medial teregoid muscle. Now let's take the artery. Let's start off with this artery that we see here. This is the maxillary artery. How does the maxillary artery start? It starts as the external parotid artery. This is the external parotid artery. It runs inside the parotid gland which has been removed, and this is the parotid, we have removed the deep part of the parotid gland. Inside the parotid gland, it diverges into a larger terminal division, which we can see here, this is the maxillary artery, and a smaller terminal division, that is the suprincial temporal artery. Before I go to the maxillary artery, let me quickly finish off the suprincial temporal artery. The suprincial temporal artery as you can see is tortuous, and it runs in front of the tragus of the ear, and then it runs up in the suprincial temporal fascia here, and it runs to the scalp in front of the ear. You can feel the pulsation of the suprincial temporal artery against the zygomatic arch which has been removed here. So this is about the suprincial temporal artery. Let's come back to the maxillary artery. The maxillary artery has got three parts. The first part is before the lateral teregoid muscle. That's called the mandibular part. The second part is, in most cases, it is supposed to be superficial to the lateral teregoid, but in this particular category, we can see it is going deep to the lateral teregoid, which also is rarely possible, and it is mentioned in textbooks. That is the second part, which is against the lateral teregoid muscle. That is also known as the teregoid part. And the third part goes through the terego maxillary fissure into the terego palatin fossa, which is known as the terego palatin part. So in the intratemporal fossa, we have the first part and the second part. So let's take a look at the first part. The branches of the first part. The branches of the first part are five. We can see this branch here. This is the deep oricular. The deep oricular artery supplies, you can see it's supplying the parotid gland. It also supplies the temporal mandibular joint. It supplies the external artery maintenance and outer surface of the tympanic membrane. Just under that, next to that is the anterior tympanic, which is partly cut here. Anterior tympanic enters the tympanic cavity from the front. That's why it's called anterior tympanic. And it supplies the tympanic membrane from the inner side. Then we have a very important branch that we can see here. This is the middle menageal artery, which is running in relation to the lateral teregoid. This middle menageal artery enters through the forearm and spinal sum to the cranial cavity. And it supplies a large area of the dura of the interior of the skull, especially in the middle cranial fossa and posterior cranial fossa by means of anterior and posterior branch. This middle menageal artery has got a very important clinical significance. As it is running up, it runs in relation to the tereon, which is under the temporalis muscle. And it fractures the tereon, the middle menageal artery can rupture and can produce a very serious life-threatening condition called extradural hematoma, which will require immediate evacuation or the patient can die. So that's about the middle menageal artery. In this case, we cannot see very clearly, but just adjacent to the middle menageal artery, there will be another branch called the accessory menageal artery, which enters the cranial cavity through the foremen ove, which also supplies the meninges. So that's the fourth branch. And the fifth branch that we can see here is this one. This is the inferior alveolar artery, which enters the mandibular foremen and runs in the mandibular canal. And it supplies the lower teeth. And then it comes out through the mental foremen in the chin and becomes known as the mental artery, which supplies this region. So these are the five branches of the first part. The second part, which is deep in this case to the lateral teregoid, but in most cases, it is superficial, supplies four muscular branches. The deep temporal, which run to the temporalis muscle, the teregoid, mesatric, and buccal. So these are the four branches. And the third part, of course, we cannot see. So these are the two parts of the maxillary artery. In this connection, I can mention one clinical correlation. One of the branches of the third part supplies the septum of the nose and participates in a nasal plexus. In patients who have chronic intractable epistaxis, which cannot be stopped by conservative measures, we enter the intratemporal fossa or the teregopalatin fossa through the maxilla from the upper lip. And we can ligate either the terminal part of the maxillary artery or the sphenopalatin artery. And that is known as the trans-intral approach to maxillary artery ligation to stop intractable epistaxis. That is all for this part of the video. Stay tuned for the next video. Thank you very much.