Parotid, temporal, infratemporal, and pterygopalatine regions week 2 Flashcards
What does the zygomatic arch do for the infratemporal fossa?
What passes through the petrotypanic fissure?
Zygomatic arch - protects the infratemporal fossa
Petrotympanic fissure - site of exit for the Chorda tympani nerve from the skull and into the infratemporal fossa (not shown in attached pic)
Identify the parts of this bone. What bone is it?
Identify the parts of the sphenoid bone. State what passes through each foramen.
Identify the parts of the mandible.
Identify the parts of the mandible.
What is the function of the following parts of the mandible:
condylar process
ramus
coronoid process
mandibular foramen
lingula
mylohoid line
- Condylar process - articulates with the temporal bone forming the temporomandibular joint.
- Ramus – a broad smooth surface acting as a strong attachment site for the masseter muscle.
- Coronoid process for attachment of the temporalis muscle.
- Mandibular foramen – entrance of the inferior alveolar nerve (a branch of V3).
- Lingula – attachment site of the sphenomandibular ligament.
- Mylohyoid line: where mylohyoid muscle attaches
What kind of joint is the temporomandibular joint (TMJ)? What kind of cartilage lines this joint?
What does the articular disk do?
What ligaments add further reinforcement to this joint?
The temporomandibular joint (TMJ) is a synovial joint and lined with fibrocartilage instead of hyaline cartilage. An articular disk divides the joint into upper and lower parts. The joint capsule is lined with a synovial membrane and reinforced with ligaments.
Three extracapsular ligaments add further reinforcement:
- Lateral ligament (part of the joint capsule
- Sphenomandibular ligament (attaches spine of the sphenoid to the lingula)
- Stylomandibular ligament (attaches styloid process to the angle of the mandible)
What are the movements of the TMJ? What muscles function in each movement?
4 movements:
- Protrusion (jaw juts forward)
- Retraction (jaw is pulled back)
- Elevation (mouth is closed)
- Depression (mouth is open)
Movements at the TMJ are most often a combination of these 4 motions.
What structures pass through the parotid gland?
The external carotid artery , superficial temporal and maxillary veins and facial nerve pass through the parotid gland.
Key concept: There are numerous structures that travel through the parotid gland. Swelling in the gland can compromise the gland as well as any structures passing through the gland. Compression/interruption of the facial nerve and its branches will produce paralysis of the muscles of facial expression on the side of the injury.
The parotid gland is positioned lateral to the temporomandibular joint and ramus of the mandible and extends from the zygomatic arch to the angle of the mandible. The parotid duct extends from the gland anteriorly to pierce the buccinator muscle and enter the oral cavity.
What is the most prominent structure in the temporal fascia?
The temporalis muscle is the most prominent structure in the temporal fossa. Place your fingers on the side of your head, make a chewing motion and you can feel the temporalis muscle.
What encloses the temporalis muscle?
What 2 things does the temporalis connect?
What is the prinicple function of the temporalis muscle?
The temporalis muscle is enclosed by the temporal fascia on its outer surface. The muscle attaches the temporal fossa with the coronoid process of the mandible. The principle function of this muscle is to close the jaw (elevate the mandible.)
Identify the arterial and nervous components of the temporal fossa.
What are the general contents of the infratemporal fossa?
The infratemporal fossa is filled with muscles and the nerves, arteries and veins that supply them.
Identify the muscles of the infratemporal fossa.
What does the medial pterygoid muscle do? What is its relationship to the mandibular nerve?
What is the action of the lateral pterygoid muscle?
The medial pterygoid muscle functions in elevation and protrusion of the mandible at the TMJ. It sits medial to the mandibular nerve (V3).
The lateral pterygoid functions in protrusion of the mandible at the TMJ (pull condylar process forward).
Identify the numbered arteries.
What foramen does the inferior alveolar aa enter? What does it supply?
What is the relationnship of the deep temporal artery to the temporalis muscle?
Maxillary Artery Branches:
- Middle meningeal – enter middle cranial cavity through foramen spinosum .
- Inferior alveolar – enters the inferior alveolar foramen to supply the teeth.
- Deep temporal - supplies the temporalis muscle
- Masseteric – supplies the masseter muscle
- Buccal – supplies the buccinator muscle
What vein(s) drain the region supplied by the branches of the maxillary artery? What is significant about this/these vein(s)?
The pterygoid plexus of veins drains the region supplied by the branches of the maxillary artery; these veins have no valves, thus pressure can force a backward/reverse flow of blood; this is a potential route for infection in the head and neck.
What kind of innervation does each branch of the trigeminal nerve provide? To what structures?
The mandibular division of the trigeminal nerve is the only division of the trigeminal nerve that is both sensory and motor.
V1 - Ophthalmic - sensory to skin of orbital region and nose
V2 - Maxillary - sensory to skin of maxillary region
V3 - Mandibular - sensory to skin of mandibular region, anterior 2/3 of tongue and adjacent mucous. Motor to muscles of mastication
What is the pterygopalatine fossa? What is the general purpose of it?
Where is it located?
What are the boundaries of the pterygopalatine fossa?
The pterygopalatine fossa can be best understood as a distribution center for innervation to orbital, nasal and other facial structures.
The Pterygopalatine Fossa is:
- in the middle of the head – just behind the face.
- shaped like an “upside down tear drop”.
- communicates with numerous regions
The walls of the pterygopalatine fossa are formed by parts of the palatine, maxilla, and sphenoid bones:
- anterior wall - posterior surface of the maxilla;
- medial wall - lateral surface of the palatine bone;
- posterior wall - parts of the sphenoid bone.
What is located within the pterygopalatine fossa?
What structures pass through the pterygopalatine fossa?
The pterygopalatine fossa is:
- a major site of distribution for the maxillary nerve [V2].
- a site of the terminal part of the maxillary artery.
- a location for parasympathetic fibers from the CN VII and sympathetic fibers that join branches of V2 in the pterygopalatine fossa.
- contains the pterygopalatine ganglion.
attached is slide 36 of notes. must know this slide!
The ____ ____ and its branches are the major arterial supply for the infratemporal fossa and center portions of the face.
The maxillary artery and its branches are the major arterial supply for the infratemporal fossa and center portions of the face.
We know the branches of the maxillary artery in the infratemporal fossa. How does the maxillary artery go from the infratemporal fossa to the pterygopalatine canal?
What does the maxillary artery terminate as?
What are the branches of the maxillary artery within the pterygopalatine fossa?
The maxillary artery enters the pterygopalatine fossa through the pterygomaxillary fissure and terminates as the sphenopalatine artery. The maxillary artery has branches that accompany branches of the V2.
Important branches to know are the:
- Infra-orbital
- Greater Palatine
- Pharyngeal (do not dissect)
- Sphenopalatine (termination of the maxillary artery)
- Artery of the Pterygoid Canal (do not dissect).
Remember that the pterygopalatine fossa is like a distribution center for branches of the maxillary nerve (V2).
Name the the branches of the maxillary nerve within the pterygopalatine fossa.
You should try to locate and identify the maxillary division of the trigeminal nerve, pterygopalatine ganglion, infraorbital nerve and posterior superior alveolar nerve. However, you should know the following branches pass from the pterygopalatine fossa, but do not dissect them: Orbital branches; Nasal Nerves; Pharyngeal nerve; Zygomatic nerve.
Where are the cell bodies located for preganglionic sympathetic neurons that innervate the head?
Where do the postganglionic sympathetic fibers arise from?
How do postganglionic sympathetic fibers reach their targets?
Sympathetic Nerve Supply to the Head.
- preganglionic fibers originate at the T1 spinal nerve level.
- postganglionic sympathetic fibers from superior cervical sympathetic ganglion.
- postganglionic fibers travel with the internal carotid plexus and its branches.
Explain the sympathetic and parasympathetic innervation of the submandibular and sublingual glands as well as the lower oral cavity.
Be sure to state the pathway these nerves take to innervate their targets.
Sympathetic - sympathetic plexus travels with the external carotid artery and follow branches to the gland.
Parasympathetic
- Chorda Tympani Nerve (from CN VII – facial) carries preganglionic parasympathetic fibers.
- Chorda tympani passes through the middle ear and exits via petrotympanic fissure to join (hitchhike) on lingual nerve.
- These preganglionic fibers then exit the lingual nerve to synapse on the submandibular ganglion.
- Postganglionic fibers continue to submandibular/sublingual glands and lower oral cavity.
State all of the parasympathetic ganglia in the head.
State what cranial nerves are involved, what nerves synapse on each ganglion, and the function of their innervation.
attached is pg 89 of course notes
