The Infratemporal and Temporal Fossa 3

Question 1

What is the function of parasympathetic fibres that run in the auriculotemporal nerve to the parotid salivary gland?

Answer 1

They bring about secretion of saliva from the parotid gland.

Question 2

Other than parasympathetic fibres, what else passes through the otic ganglion?

Answer 2

Like all parasympathetic ganglia in the head, sympathetic neurones also pass through and dont synapse in it and they also run on to the parotid gland.

Question 3

What happens to the external carotid artery as it approaches the infratemporal fossa?

Answer 3

It divides into 2 terminal branches which are the maxillary and superficial temporal arteries.

Question 4

Describe the path of the maxillary temporal artery/

Answer 4

It passes in a tortuous fashion through the infratemporal fossa and it usually passes between the 2 heads of the lateral pterygoid muscle to enter the pterygopalatine fossa.

Question 5

What do the branches of the maxillary temporal artery supply?

Answer 5

This gives off many branches in the infratemporal and in the pterygopalatine fossa.

These branches supply the ear, nose, palate and pharynx.

Question 6

Where do the branches of the outer 1/3 of the maxillary temporal artery go?

Answer 6

They go to the bony structures such as the middle ear, the maxilla and the mandible.

Question 7

Where do branches from the middle third of the maxillary temporal artery go?

Answer 7

They go to each of the muscles of mastication.

Question 8

Where do branches of the innermost third of the maxillary temporal artery go?

Answer 8

This has already been studied in the context of the nose.

They arise in the sphenopalatine foramen and for the most part they travel into bony structures and canals to reach their destination.

Question 9

What are the 2 important branches of the maxillary temporal artery?

Answer 9

• inferior alveolar artery – becomes the mental artery
• middle meningeal artery

Question 10

What is the path of the inferior alveolar artery?

Answer 10

This accompanies the inferior alveolar nerve into the mandible and through the chin as the mental artery.

Question 11

What does the inferior alveolar artery supply?

Answer 11

It supplies the pulps of the teeth and the body of the mandible with blood.

Question 12

Why is the middle meningeal artery important?

Answer 12

Because it is a nutrient artery for the bones of the vault of the skull.

Question 13

What is the path of the middle meningeal artery?

Answer 13

• ascends through the foramen spinosum
• while it ascends it gains the interval between the dura and the periosteum of the skull

Question 14

Where does the accessory meningeal artery ascend through?

Answer 14

It ascends through the foramen ovale.

Question 15

What does the middle meningeal artery help to supply?

Answer 15

It helps to supply the ganglion of the trigeminal nerve.

Question 16

What do branches of the maxillary artery supply?

Answer 16

They supply the external acoustic meatus and the tympanic membrane.

Question 17

What do branches of the maxillary artery help to supply?

Answer 17

They help to supply the external acoustic meatus and the tympanic membrane.

Question 18

What do muscular branches of the maxillary nerve follow?

Answer 18

They follow branches of the mandibular nerve.

Question 19

What muscles to the muscular branches of the maxillary nerve supply?

Answer 19

They supply all of the muscles of mastication.

Question 20

In the pterygopalatine fossa, what do muscular branches of the maxillary artery follow?

Answer 20

They follow each of the branches of the pterygopalatine ganglion.

One important artery follows the infraorbital nerve and emerges with the infraorbital nerve on to the cheek through the infraorbital foramen.

Question 21

What is the pterygoid venois plexus?

Answer 21

This is a network of veins that lies around the pterygoid plexus.

Question 22

Where does the pterygoid plexus recieve blood from?

Answer 22

It recieves blood from the veins that accompany the local arteries near the pterygoid muscles.

Also recieves blood from the inferior orbital veins via the inferior orbital fissure.

Question 23

What does the pterygoid venous plexus drain into?

Answer 23

It drains into a pair of short maxillary veins eventually. These join the superficial temporal vein to form the retromandibular vein.

Question 24

Where does the short maxillary vein lie?

Answer 24

It lies deep to the neck of the mandible.

Question 25

What does the deep facial vein connect the pterygoid venous plexus with?

Answer 25

With the facial vein.

Question 26

What is the pterygoid venous plexus connected to through the foramen ovale?

Answer 26

It is connected to the cavernous sinus.

Question 27

Why is the connection of the pterygoid venous plexus to the cavernous sinus important?

Answer 27

Because infection, for example to the upper wisdom tooth, can track up this path if it is unchecked.

Local anaesthetic that is give to block the posterior superior alveolar nerves at the back of the maxilla can easily be misplaced into the pterygoid venous plexus from where they may drain into the carvernous sinus and when we yawn we squeeze venous blood out of the pterygoid plexus therefore large amounts of local anaesthetic can easily find their way into the cavernous sinus and the effect may be transient anaeasthesia of the 6th cranial nerve = abducens nerve which is the only cranial nerve in the cavernous sinus that runs free in the venous blood beneath the carotid artery.

Therefore, if a patient is having their wisdom tooth removed but they complain of seeing double then it is important to test the abducens nerve and reassure the patient that they will recover.

Question 28

How is the abducens nerve different from other cranial nerve?

Answer 28

The abducens nerve is the only cranial nerve in the cavernous sinus that runs free in the blood, beneath the carotid artery however the other cranial nerves run in the dura of the wall of the of the sinus and therefore these cranial nerves are more protected from the effects of local anaesthetic in the venous blood.

Question 29

What structures are contained in the posterior part of the infratemporal fossa?

Answer 29

• internal carotid artery
• internal jugular veins

these leave the skull through their respective foramina.

• 9-12th cranial nerves

superimposed upon and between the above structures is the styloid process and its muscles.

Question 30

What type of joint is the temporomandibular joint?

Answer 30

It is a synovial articulation.

Question 31

What is the tempromandibular joint an articulation between?

Answer 31

Between the glenoid fossa and the condyle or head of the mandible.

Question 32

Where is the glenoid fossa?

Answer 32

This is on the undersurface of the mandible.

Question 33

What is attached to the articular margins of the temporomandibular joint?

Answer 33

A fibrous capsule

Question 34

What does the lateral part of the fibrous capsule surrounding the temporomandibular joint thicken to form?

Answer 34

THe lateral ligament.

Question 35

What is the joint cavity of the temporomandibular joint divided?

Answer 35

It is divided in 2 completely by a disc of fibrous connective tissue.

Question 36

What is the disc that divides the temporomandibular jiont cavity called?

Answer 36

It is called the meniscus sometimes

Question 37

Describe the upper cavitiy of the temporomandibular joint?

Answer 37

The upper cavity is long

Question 38

What does the upper cavity of the temporomandibular joint include?

Answer 38

• a concave surface of the temporal bone
• a convex bulge on the undersurface of the root of the zygomatic arch = articular eminence

Question 39

What does the upper chamber of the joint capsule allow?

Answer 39

It allow the sliding of the head of the mandible forwards onto the articular eminence.

Question 40

What happens during opening of the jaw?

Answer 40

The mandibular condyles slides forwards on to the eminence.

However, it is likely that only the first millimetre or 2 of opening the kaw is entirely simply rotation in the lower joint compartment.

The rest is a combination of both sliding and hinge movements.

The capsule of the joint is lax enough to allow for small side to side movements to occur.

Question 41

Describe the lower cavity of the joint capsule.

Answer 41

It has a simpler arrangement and allows hinge like rotation during the opening and closing of the mouth.

Question 42

What 2 other ligaments attach to the mandible but are unlikely to limit the movements of the joint to a great extent?

Answer 42

• sphenomandibular ligament
• stylomandibular ligament

Question 43

Where does the sphenomandibular ligament pass from, to?

Answer 43

It passes from the spine of the sphenoid bone on the base of the skull to the lingula which is a spur of bone that flanks the mandibular foramen.

Question 44

What is the sphenomandibular ligament a remnant of?

Answer 44

It is a remnant of the perichondrium of Meckel’s cartilage of the first pharyngeal arch.

Question 45

Where does the stylomandibular ligament arise from and attach to?

Answer 45

It arises from the styloid process and is attached to the angle of the mandible.

Question 46

What is the stylomandibular ligament a condensation of?

Answer 46

It is a condensation of the deep cervical investing fascia in the neck that spans 2 bony points.

Question 47

What happens when the mouth is opened?

Answer 47

• condyle and articular disc move forwards and downwards onto the articular eminence of the temporal bone
• head of the condyle rotates on the lower surface of the disc

Question 48

When does protrusion occur?

Answer 48

This occurs when both the mandibular heads move anteriorly, together with their discs, as when sticking the chin out.

Question 49

What muscle pulls the condyles and discs forwards?

Answer 49

The lateral pterygoid muscle. q

Question 50

How does the lateral pterygoid muscle run?

Answer 50

It runs anteroposteriorly from origin to insertion.