Pterygopalatine Fossa and ANS Pathways of Head and Neck

Question 1

The pterygopalatine fossa is a small space below the apex of the _________and behind the infratemporal surface of the ________.

Answer 1

orbit; maxilla

Question 2

Why is the pterygopalatine fossa important anatomically and clinically?

Answer 2

It is important anatomically and clinically because critical neurovascular pathways to the orbit, nasal cavity, palate and pharynx converge and diverge at this space.

Question 3

What are main contents of the pterygomandibular fossa?

Answer 3

• the pterygopalatine ganglion
• the maxillary nerve and many of its branches
• the third part of the maxillary artery

Question 4

The pterygopalatine fossa is directly in front of foramen __________.

Answer 4

rotundum

Question 5

The maxillary artery enters the pretygopalatine fossa, after it comes in through the _________.

Answer 5

infratemporal fossa

Question 6

The pterygopalatine fossa communicates with the nasal cavity medially via the ____________.

Answer 6

sphenopalatine foramen

Question 7

The pterygopalatine fossa communicates with the orbit,antero-superiorly, via the ______________.

Answer 7

medial end of the inferior orbital fissure

Question 8

The pterygopalatine fossa communicates with the infratemporal fossa laterally via the______________

Answer 8

pterygomaxillary fissure

Question 9

The pterygopalatine fossa communicates with the oral cavity inferiorly via the ______.

Answer 9

greater palatine canal

Question 10

The pterygopalatine fossa communicates with the middle cranial fossa postero-superiorly via ___________and _________.

Answer 10

foramen rotundum; pterygoid canal

Question 11

The pterygopalatine fossa communicates with the pharyngeal wall posteriorly via _____________.

Answer 11

palatovaginal canal

Question 12

The pterygopalatine fossa communicates with the maxillary sinus anteriorly via ___________

Answer 12

alveolar foramina

Question 13

Label

Answer 13

Question 14

_____________= Greater petrosal + Deep petrosal nerves

Answer 14

Vidian nerve

Question 15

Which two foramen open the pterygopalatine fossa?

Answer 15

• Posteriorly, the foramen rotundum, transmits the maxillary nerve from the middle cranial fossa.
• Medially, the sphenopalatine foramen transmits nerves and vessels through the posterior, medial wall of the nasal cavity.

Question 16

What three canals open in the pterygopalaine fossa?

Answer 16

Posteriorly, the pterygoid canal transmits the nerve of the pterygoid canal (Vidian nerve) from the middle cranial fossa.

Also posteriorly, the palatovaginal canal transmits nerves and vessels to the upper (naso)pharynx.

Inferiorly, the greater palatine canal transmits nerves and vessels to the hard and soft palate.

Question 17

What are the branches of the third part of the maxillary artery? What does each supply?

Answer 17

•Infraorbital a.: Inferior part of the orbit, maxilla, maxillary sinus, nose, upper lip, and the canin and incisor teeth of maxilla

•Sphenopalatine a.: Walls of the nasal cavity, paranasial sinuses, nasopharynx, and the anterior region of the palate

•Posterior Superior Alveolar a.: Molar and premolar teeth of the maxilla

•Greater (Descending) Palatine a.: Hard palate, soft palate, and the palatine tonsils

•A. of the Pterygoid Canal:

•Pharyngeal a.: Stylopharyngeus and middle pharyngeal constrictor

Question 18

Which nerve branches the pterygopalatine fossa come directly from V2?

Answer 18

To Orbit: Infraorbital n. and Zygomatic n.

To Maxilla: Posterior, Middle and Anterior Superior Alveolar nn.

To Dura: Meningeal n.

To Pterygopalatine Ganglion: Ganglionic n.

Question 19

Which branch of the maxillary nerve are associated with the pterygopalatine ganglion?

Answer 19

Orbital n

Nasopalatine nerve

Greater palatine nerve

Lesser Palatine nerve

Pharyngeal nerve

Posterior superior palatine nerve

**NOTE: The pterygopalatine ganglion sits right below the maxillary nerve.

Question 20

What’s the course of the infraorbital nerve through the pretygopalatine fossa?

Answer 20

Infraorbital nerve- some axons pass inferiorly through the ganglion (without synapsing) on their way to their targets. Go down the palatine canal to form the greater and lesser palatine nerves- provides innervation to the hard and soft palate.

Question 21

•Sensation for nasopharynx is from _________

Answer 21

V2.

Question 22

What structures are supplied by the pterygopalatine ganglion?

Answer 22

Lacrimal gland

Ocular choroidal vessels

Glands of the nasal mucosa.

Question 23

Characteristics of the pterygopalatine ganglion

Answer 23

• It is the largest of the peripheral parasympathetic ganglia
• Lies just below the maxillary nerve as it crosses the pterygopalatine fossa.
• Supplies the lacrimal gland, ocular choroidal vessels and the glands of the nasal mucosa.
• The neurons of the pterygopalatine ganglion use acetylcholine as their main transmitter with many also using VIP (Vasoactive intestinal polypeptide) and nitric oxide.

Question 24

What is the course of the preganglionic parasympathetic fibers of the pterygopalatine ganglion?

Answer 24

1. Pre-ganglionic cell bodies found in superior salivatory nucleus of the medulla join the facial nerve and enter the internal acoustic meatus.
2. Leaves VII at the genu as the greater petrosal nerve in the middle cranial fossa
3. From the internal auditory meatus the facial nerve turns at the geniculate ganglion to go down the facial canal. Greater petrosal nerve exits anteriorly from the geniculate ganglion and pops out of the roof of the temporal bone In the middle cranial fossa.
4. At the border of the foramen lacerum, the deep petrosal nerve joins it and they go through the nerve of the pterygoid canal.
5. The nerve to the pterygoid canal goes through the base of the sphenoid. The ganglion is at the opening of the pterygoid canal.

So the root of the facial nerve comes out of the geniculate ganglion, goes forward as the great petrosal through the pterygoid canal and synapses on the pterygopalatine ganglion.

Question 25

Where do the postganglionic parasympathetic fibers of the pterygopalatine ganglion go?

Answer 25

• Join infraorbital nerve, then follow zygomatic nerve to lacrimal nerve. Target: lacrimal gland, stimulating tears.
• Join trigeminal branches to target nasal and palatine glands, stimulating mucous secretion.

Question 26

Explain the sympathetic fibers of the pterygopalatine ganglion

Answer 26

•Preganglionic neurons: Intermediate (lateral) horn of upper thoracic cord. Follow ventral root, white rami communicans, cervical sympathetic trunk, to synapse in superior cervical ganglion

•Post-ganglionic neurons: Internal carotid nerve forms a plexus around the internal carotid artery, into cranium. Deep petrosal nerve exits and passes through cartilage of foramen lacerum; joins greater petrosal nerve to form nerve pterygoid canal (Vidian) . Pass through pterygopalatine ganglion without synapsing. Targets: lacrimal, nasal and palatine glands to inhibit secretion. (May also follow the external carotid artery to reach nasal and palatine canals.

Question 27

What synpases in at the pterygopalatine ganglion?

Answer 27

Parasympathetics

*Sympathetics just bypass the ganglion

Question 28

Label

Answer 28

Question 29

All glands above the level of the oral fissure are innervated by ______________

Answer 29

Greater petrosal nerve of VII

Question 30

All glands below the level of the oral fissure are innervated by __________

Answer 30

Chorda tympani of VII

Question 31

What are the preganglionic and postganglionics of the ciliary ganglion?

Answer 31

•Preganglionic: E-W nucleus sends axons with oculomotor nerve to synapse on ciliary ganglion

•Postganglionic: Cause constriction of ciliary muscle (near focus) and sphintor pupillae (constrict pupil)

*Sensory fibers go through the ganglion without synapsing

Question 32

What are the preganglionic and postganglionics of the submandibular ganglion?

Answer 32

•Preganglionic: Chorda tympani comes off the facial nerve and goes over the tympanic membrane. Come out of the petrotympanic fissure, through the infratympanic fossa and joined the lingual nerve branch of the mandibular division of trigeminal. Travels with the lingual nerve and synapses in the submandibular ganglion.

•Post-ganglionic fibers travel to the submandibular gland and cause salivation. Some fibers hop back onto the lingual nerve and travel to the sublingual gland (in the floor of the mouth)

Question 33

What are the preganglionic and postganglionics of the otic ganglion?

Answer 33

•Preganglionic: Inferior salivatory nucleus sends axons with IX. Branch off as tympanic nerve entering tympanic cavity. Sensory fibers form tympanic plexus, but parasympathetics re-converge as lesser petrosal, running parallel to greater petrosal. Exit foramen ovale. Synapse in otic ganglion

•Postganglionic: follow auriculotemporal parotid gland.

Question 34

What are the preganglionic and postganglionics of the submucosal and myenteric ganglia of enteric nervous system; cardiac and pulmonary ganglia ganglion?

Answer 34

•Preganglionic: Dorsal motor nucleus of vagus; nucleus ambiguus (for the heart)

•Postganglionic: Walls of thoracic and abdominal viscera

NOTE: Visceral ganglia are in the walls of the organs.

Question 35

There are multiple innervation pathways toward the lacrimal gland.

Answer 35