(E1) 5 - The Parotid Fossa

Question 1

What is the shape of the parotid gland?

Answer 1

Wedge

Question 2

What is the medial boundary of the parotid gland?

Answer 2

The styloid process

Question 3

What is the lateral boundary of the parotid gland?

Answer 3

Superficial parotid fascia

Question 4

What is the anterior boundary of the parotid gland?

Answer 4

• Masseter Muscle
• Ramus & Neck of the mandible
• Stylomandibular fascia (part of deep parotid fascia)

Question 5

What does the stylomandibular fascia connect?

Answer 5

The mandible to the styloid process

Question 6

What is the posterior boundary of the parotid gland?

Answer 6

• SCM
• Posterior Digastric Muscle
• Stylohyoid muscle
• deep fascia of these muscles

Question 7

What is the superior limit of the parotid gland?

Answer 7

Superficial parotid fascia

Question 8

What is the inferior limit of the parotid gland?

Answer 8

Angular tract (between angle of mandible and SCM)

Question 9

Image of the Parotid Gland

Answer 9

Question 10

What are the 3 main parotid bed fascia’s?

Answer 10

• Superficial fascia
• Superficial parotid fascia
• Deep parotid fascia

Question 11

What is the superficial parotid fascia?

Answer 11

Deep fascia but superficial to the parotid; continuation of the investing fascia of the neck

Question 12

What is the deep parotid fascia?

Answer 12

(continuation) Stylomandibular fascia - fascia surrounding stylohyoid and posterior belly of digastric and connecting to SCM and styloid process (deep to parotid)

Question 13

What are the contents of the parotid fossa?

Answer 13

• Parotid gland
• Facial Nerve VII
• External carotid artery and branches
• Retromandibular vein and its branches

Question 14

Describe the type of gland the parotid gland is

Answer 14

Pure serous and encapsulated

Question 15

What are the 5 branches of the facial nerve?

Answer 15

(ten zebras bit my cookies)

Question 16

Which fascia encapsulate the parotid galnd?

Answer 16

Deep parotid fascia and superficial parotid fascia

Question 17

What is the angular tract?

Answer 17

Inferior junction of superficial and deep fascias - separates the parotid gland (posterior) from submandibular gland (anterior)

Question 18

Where does the parotid duct exit?

Answer 18

Anterior aspect of parotid gland thru the superficial fascia. Crosses masseter; turns medially and pierces buccinator muscle

Question 19

Where does the parotid duct empty?

Answer 19

Into oral cavity via parotid papilla (max 2nd molar)

Question 20

What is the sensory innervation for the parotid gland?

Answer 20

• Great auricular nerve (cervical plexus)
• Auriculotemporal nerve (Branch of CN V)

Question 21

Where does Great Auricular supply sensory information?

Answer 21

Question 22

What does the Auriculotemporal nerve supply?

Answer 22

Question 23

*** Describe in order the parasympathetic innervation of the parotid gland. (8 steps)

Answer 23

1. Glossopharyngeal N. exits the brain through the jugular foramen
2. Passes through a GSA ganglion but does not communicate because it is GVE (parasymp)
3. The tympanic branch of IX comes off and goes back into the skull via the tympanic canaliculus
4. Makes its way to the middle ear and forms the Tympanic plexus
5. Coming off the tympanic plexus is the lesser petrosal nerve (preganglionic)
6. Lesser petrosal nerve travels through foramen ovale and makes its way to the otic ganglion (parasymp ganglion)
7. Synapse at the otic ganglion. Postganglionic fibers come off and join the auriculotemporal nerve (V3)
8. Make their way to the parotid gland.
   (now have sensory as well as sensory with GVE)

Question 24

What are the external carotid branches found in the parotid fossa?

Answer 24

• Superficial temporal arteries (posterior and anterior) (runs with auriculotemporal n.)
• Transverse facial artery (branch of the superficial temporal)
• Maxillary A. (deep to mandible)
• Posterior Auricular A.

Question 25

What veins form the retromandibular vein?

Answer 25

Question 26

The anterior division of the retromandibular vein joins the ____ vein to form the ________ and drains into _______

Answer 26

Facial Vein Common Facial Vein Jugular Vein

Question 27

The posterior division of the retromandibular vein joins the ____ vein to form the ________

Answer 27

Posterior Auricular External Jugular Vein

Question 28

Describe the pathway of Facial Nerve (VII)

Answer 28

- Exits stylomastoid foramen - passes between and innervates posterior digastric and stylohyoid

Question 29

Is the facial nerve sensory or motor?

Answer 29

MOTOR ONLY - to muscles of facial expression

Question 30

Does the facial nerve provide any innervation to the parotid gland?

Answer 30

No - but it passes thru it

Question 31

Within the gland, the facial nerve divides into what?

Answer 31

- Temporofacial branch - Cervicofacial branch

Question 32

________ divides the parotid into superficial and deep fascias

Answer 32

CN VII - Facial Nerve

Question 33

What is Parotitis?

Answer 33

Infection of the parotid gland - often caused by bacteria (xerostomia) - typically bilateral, can be uni

Question 34

What virus causes mumps?

Answer 34

Paramyxovirus

Question 35

Describe the symptoms associated with Mumps

Answer 35

Question 36

What is a sialolith?

Answer 36

Salivary calculus or stone

Question 37

What is the most common form of a parotid tumor?

Answer 37

Pleomorphic adenoma - typically benign

Question 38

What is Bell's palsy?

Answer 38

Unilateral facial paralysis due to facial nerve involvement (prognosis: weeks to months)