1. Human Anatomy تشريح / د . سيف (م7 ) ثاني اسنان موصل 7 / 12 / 2015
تشريح / د . سيف (م7 )
ثاني اسنان موصل
7 / 12 / 2015
د . سيف (م 7)
Human Anatomy

2. Parotid Region Boundaries: Superior :external acoustic meatus.
Inferior : angle of mandible.
Anterior : Masseter muscle.
Posterior: mastoid process.

4. Parotid Gland
The parotid gland is the largest salivary gland and is composed mostly of serous acini. It lies in a deep hollow below the external auditory meatus, behind the ramus of the mandible, and in front of the sternocleidomastoid muscle. The facial nerve divides the gland into superficial and deep lobes. The parotid duct emerges from the anterior border of the gland and passes forward over the lateral surface of the masseter. It enters the vestibule of the mouth upon a small papilla opposite the upper second molar tooth.

7. Contents of parotid region:
Parotid gland
The external carotid artery enters the lower part of the posteromedial surface. Ascending within the substance of the gland it divides into its terminal branches (superficial temporal and maxillary) that emerge on the anteromedial surface of the gland
The retromandibular vein lies in the substance of the parotid gland superficial to the external carotid artery.
The trunk of the facial nerve enters the posteromedial surface. Within the gland it divides into its terminal branches that emerge from the anteromedial surface near its anterior margin. The cervical branch of the nerve emerges from the lower end of the gland.
The auriculotemporal nerve passes laterally between the neck of the mandible and the superior surface of the gland. It gives branches to the gland.

8. TEMPORAL REGION
The temporal region overlies the temporal fossa present on the lateral aspect of the skull. The fossa is bounded superiorly and inferiorly by the temporal line and inferiorly by the zygomatic arch. The lower part of the temporal region is overlapped by the auricle. A thick fibrous membrane, the temporal fascia covers the region. This fascia is attached superiorly to the temporal lines, and inferiorly to the zygomatic arch.

10. Boundaries of the temporal region
The fossa is bounded
superiorly and inferiorly by the temporal lines.
inferiorly by the zygomatic arch.
anteriorly by the frontal process of the zygoma and the zygomatic process of the frontal bone.

12. Contents of temporal region:
A. Temporalis muscle:
*Origin: The temporalis arises from the temporal fossa on the lateral aspect of the skull. The area includes parts of the frontal, parietal, and squamous temporal bones and of the greater wing of the sphenoid. The tendon passes deep to the zygomatic arch.
*Insertion: Into coronoid process of mandible.
*Nerve Supply: Deep temporal branches of the mandibular nerve.
*Actions: The temporalis helps to close the mouth by elevating the mandible.

14. B. The nerves presents in the temporal region are:
1. The auriculotemporal nerve emerges from under cover of the upper end of the parotid gland. The nerve ascends into the temporal region and scalp and divides into branches that supply them.
2. The temporal branch of the facial nerve runs upwards and forwards to reach the frontalis muscle that it supplies. It also helps to supply the orbicularis oculi and the auricular muscles.
3. The posterior auricular branch of the facial nerve is seen behind the auricle in the lower part of the temporal region. It runs backwards to reach and supply the occipitalis muscle.
4. The zygomatico-facial nerve and the zygomatico-temporal nerve are derived from the zygomatic branch of the maxillary division of the trigeminal nerve. They help to supply the skin of the region.
5. Deep to the temporalis muscle there are the (anterior, middle and posterior) deep temporal nerves. They arise from the anterior division of the mandibular nerve. The deep temporal nerves supply the temporalis muscle.

15. C. The blood vessels presents in the temporal region are:
1. The superficial temporal artery is a terminal branch of the external carotid artery. It divides into branches that supply the temporal region and scalp.
2. The superficial temporal vein is a tributary of the retromandibular vein.
3. The deep temporal arteries are branches of the maxillary artery.

19. INFRATEMPORAL FOSSA
The term infratemporal fossa is an irregular space lying below temporal fossa , deep and inferior to the zygomatic arch, deep to the ramus of the mandible, and posterior to the maxilla.
The boundaries of the infratemporal fossa are:
• Laterally: the ramus of the mandible.
• Medially: the lateral pterygoid plate.
• Anteriorly: the posterior aspect of the maxilla.
• Posteriorly: the tympanic plate and the mastoid and styloid processes of the temporal bone.
• Superiorly: the inferior (infratemporal) surface of the greater wing of the sphenoid.
• Inferiorly: where the medial pterygoid muscle attaches to the mandible near its angle

21. Contents of the infratemporal fossa:
• muscles of mastication “Inferior part of the temporalis muscle, Lateral and medial pterygoid muscles”
• Maxillary artery and Mandibular nerve.
• Pterygoid venous plexus.
• Otic ganglion.

23. Communications of the Infratemporal Fossa
infratemporal fossa communicates superiorly with middle cranial fossa through foramen ovale and foramen spinosum those open to roof of infratemporal fossa
lnfratemporal fossa communicates with temporal fossa though the foramen formed by the zygomatic arch
infratemporal fossa communicates with orbit via inferior orbital fissure .
infratemporal fossa communicates Medially with pterygopalatine fossa via pterygomaxillary fissure.

24. MUSCLES OF MASTICATION 1. Temporalis muscle: previously discussed 2
MUSCLES OF MASTICATION 1. Temporalis muscle: previously discussed 2. Masseter muscle #Origin: The muscle arises from the zygomatic arch . #Insertion: Into lateral surface of ramus and angle of the mandible. #Nerve Supply: Anterior division of the mandibular nerve. #Actions: The masseter elevates the mandible to close the mouth. Its anterior fibers help in forward movement of the jaw.

25. The muscle has two heads of origin, upper and lower. #Origin:
3. Lateral Pterygoid muscle
The muscle has two heads of origin, upper and lower.
#Origin:
The upper head arises from the infratemporal surface of
the greater wing of the sphenoid bone.
The lower head arises from the lateral surface of the lateral pterygoid plate.
#Insertion:
Into a depression (pterygoid fovea) on the anterior aspect
of the neck of the mandible.
#Nerve Supply:
Mandibular nerve (anterior division).

26. 4. Medial Pterygoid muscle
#Origin:
The medial pterygoid muscle takes origin mainly from the medial surface of the lateral pterygoid plate. A superficial slip arises from the lateral aspect of the maxillary tuberosity.
#Insertion:
Medial surface of angle of mandible.
#Nerve Supply:
Mandibular nerve.
#Actions of Pterygoid Muscles:
1. The medial and lateral pterygoids of both sides acting together protract the mandible.
2. The medial and lateral pterygoids of the two sides acting alternately produce side to side chewing movements.
3. The medial pterygoid elevates the jaw. The lateral pterygoid helps in opening the mouth by pulling the head of the mandible forwards.

29. Maxillary artery
is the larger of the two terminal branches of the external carotid artery. The artery runs forwards deep to the neck of the mandible to enter the infratemporal fossa and is divided into three parts based on its relation to the lateral pterygoid muscle. The first part passes forwards deep to the neck of the mandible to reach the infratemporal fossa. Here it runs forwards along the lower border of the lateral pterygoid muscle . The second part of the artery runs forwards and upwards superficial to the lower head of the lateral pterygoid muscle. The third part of the artery passes between the upper and lower heads of the lateral pterygoid muscle to pass through the pterygomaxillary fissure thus entering the pterygopalatine fossa.

30. A. Branches of first part:
1. The deep auricular artery supplies the external acoustic meatus, the tympanic membrane and the temporomandibular joint.
2. The anterior tympanic branch supplies the middle ear and the tympanic membrane.
3. The middle meningeal artery runs upward deep to the lateral pterygoid muscle. It passes between the two roots of the auriculotemporal nerve . The artery enters the cranial cavity through the foramen spinosum. It runs forwards and laterally over the floor of the middle cranial fossa and divides into frontal and parietal branches.

31. 4. The accessory meningeal artery enters the cranial cavity through the foramen ovale. 5. The inferior alveolar artery runs downwards and forwards medial to the ramus of the mandible to reach the mandibular foramen. Passing through this foramen the artery enters the mandibular canal (within the body of the mandible) in which it runs downwards and then forwards. Before entering the mandibular canal the artery gives off a lingual branch to the tongue; and a mylohyoid branch that descends in the mylohyoid groove (on the medial aspect of the mandible) and runs forwards above the mylohyoid muscle. Within the mandibular canal the artery gives branches to the mandible and to the roots of each tooth attached to the bone. It also gives off a mental branch that passes through the mental foramen to supply the chin.

32. Accessory meningeal artery

33. B. Branches of second part:
The branches of the second part of the maxillary artery are mainly muscular. The deep temporal branches (anterior and posterior) ascend on the lateral aspect of the skull deep to the temporalis muscle. Branches are also given off to the pterygoid muscles and to the masseter. A buccal branch supplies the buccinator muscle.

34. C. Branches of third part:
The posterior superior alveolar artery descends on the posterior surface of the maxilla and gives branches that supply the molar and premolar teeth, and the maxillary air sinus.
2. The infraorbital artery enters the orbit through the inferior orbital fissure. It runs forwards in relation to the floor of the orbit, first in the infraorbital groove and then in the infraorbital canal to emerge on the face through the infraorbital foramen. It gives off some orbital branches to structures in the orbit, and anterior superior alveolar branches that reach the incisor and canine teeth. After emerging on the face the infraorbital artery gives branches to the lacrimal sac, the nose and the upper lip. The remaining branches of the third part arise within the pterygopalatine fossa

35. 3. The greater palatine artery runs downwards in the greater palatine canal to emerge on the hard palate through the greater palatine foramen. It then runs forwards near the lateral margin of the palate. Branches of the artery supply the palate and gums. Within the greater palatine canal it gives off the lesser palatine arteries that emerge on the palate through lesser palatine foramina and run backwards into the soft palate and tonsil. 4. The pharyngeal branch supplies part of the nasopharynx, the auditory tube and the sphenoidal air sinus. 5. The artery of the pterygoid canal helps to supply the pharynx, the auditory tube and the tympanic cavity. 6. The sphenopalatine artery passes medially through the sphenopalatine foramen to enter the cavity of the nose. It gives off branches to the nose and the paranasal sinuses.

37. MANDIBULAR NERVE
The mandibular nerve (CN V3) is the inferior and largest division of the trigeminal nerve .It is formed by the union of sensory fibers from the sensory ganglion and the motor root of CN V in the foramen ovale to enter the infratemporal fossa, then divides into a small anterior and a large posterior division

38. A. Branches from the Main Trunk of the Mandibular Nerve
Meningeal branch which accompany the middle meningeal artery.
Nerve to the medial pterygoid muscle, which supplies medial pterygoid muscle.
Nerve to tensor velli palatini muscle.
Nerve to tensor tympani muscle.

39. B. Branches from the Anterior Division of the Mandibular Nerve
Masseteric nerve to the masseter muscle .
Deep temporal nerves to the temporalis muscle.
Nerve to the lateral pterygoid muscle.
Buccal nerve to the skin and the mucous membrane of the cheek. The buccal nerve does not supply the buccinator muscle (which is supplied by the facial nerve), and it is the only sensory branch of the anterior division of the mandibular nerve.

40. C. Branches from the Posterior Division of the Mandibular Nerve
1. Auriculotemporal nerve, which supplies the skin of the auricle, the external auditory meatus, the temporomandibular joint, and the scalp. This nerve also conveys postganglionic parasympathetic secretomotor fibers from the otic ganglion to the parotid salivary gland.
2. Lingual nerve, which descends in front of the inferior alveolar nerve and enters the mouth. It then runs forward on the side of the tongue and crosses the submandibular duct. In its course, it is joined by the chorda tympani nerve , and it supplies the mucous membrane of the anterior two thirds of the tongue and the floor of the mouth. It also gives off preganglionic parasympathetic secretomotor fibers to the submandibular ganglion.

41. 3. Inferior alveolar nerve, which enters the mandibular canal to supply the teeth of the lower jaw and emerges through the mental foramen (mental nerve) to supply the skin of the chin. Before entering the canal, it gives off the mylohyoid nerve, which supplies the mylohyoid muscle and the anterior belly of the digastric muscle. Note: The branches of the posterior division of the mandibular nerve are sensory (except the nerve to the mylohyoid muscle).

43. The Otic Ganglion
The otic ganglion is situated just below the foramen ovale medial to the trunk of the mandibular nerve. Presynaptic parasympathetic fibers, derived mainly from the glossopharyngeal nerve, synapse in the otic ganglion. Postsynaptic parasympathetic fibers, which are secretory to the parotid gland, pass from the otic ganglion to this gland through the auriculotemporal nerve.