Oral Cavity Part 2

Question 1

What is the parotid gland and what takes place there?

Answer 1

• serous gland found in the retromandibular fossa
• parotid duct (which crosses the masseter muscle superficially, pierces buccinator and opens into oral vestibule)
• where terminal branching of external carotid artery and facial nerve takes place

Question 2

Where would you find Stensen’s duct in the oral vestibule?

Answer 2

opposite the second maxillar molar tooth

Question 3

What are the sublingual glands?

Answer 3

• mucous glands found above the mylohyoid muscle beneath the mucous membrane of the floor of the mouth
• open by 8-20 separate ducts into the floor of the mouth along the sublingual fold

Question 4

What are the submandibular glands?

Answer 4

• mixed mucous and serous glands found beneath the lower border of the body of the mandible
• ducts empty into the oral cavity at the sublingual papilla

Question 5

What is sialolithiasis and where is the most common site of this?

Answer 5

• salivary gland stones

- most commonly found in the submandibular gland

Question 6

Where is the pharynx found?

Answer 6

between base of the skull and lower border of cricoid cartilage (C6)

Question 7

Describe the divisions of the pharynx

Answer 7

• nasopharynx: posterior to nasal cavity with choana opening
• oropharynx: posterior to oral cavity with oropharyngeal isthmus opening
• laryngopharynx: level of the larynx with laryngeal inlet opening

Question 8

How are the salpingopharyngeal (superior) and salpingopalatine (inferior) folds formed?

Answer 8

salpingopharyngeus and salpingopalatine muscles run between torus tubarius and pharynx and palate respectively forming the folds

Question 9

Where is the piriform fossa?

Answer 9

between the quadrangular membrane of the larynx and the side of the pharynx

Question 10

Name the muscles of the pharynx

Answer 10

Circular muscles (constrictor muscles):

• superior pharyngeal
• middle pharyngeal
• inferior pharyngeal

Longitudinal muscles (elevator muscles):

• stylopharyngeus
• palatopharyngeus
• salpingopharyngeus

Question 11

What are the attachments of the constrictor pharyngeal muscles?

Answer 11

• superior: pterygoid hamulus and pterygomandibular raphe with buccinator
• middle: hyoid bone and stylohyoid ligament
• inferior: oblique line of thyroid cartilage and cricoid cartilage

Question 12

What is the joint place of insertion of the constrictor pharyngeal muscles?

Answer 12

pharyngeal raphe (which attaches to pharyngeal tubercle)

Question 13

What is the role of the pharyngobasilar fascia?

Answer 13

closes the gap between the occipital bone and superior pharyngeal constrictor muscle

Question 14

What is Kilian’s dehiscence?

Answer 14

the inferior most region of the inferior pharyngeal constrictor muscle, weak area

Question 15

What is the Sinus of Morgagni?

Answer 15

the space between the base of the skull and the upper free border of the superior pharyngeal constrictor muscle

Question 16

What is Passavant’s ridge/palatopharyngeal sphincter?

Answer 16

• mucosal ridge caused by superior pharyngeal constrictor or the palatopharyngeus
• encircles the posterior and lateral walls of the nasopharynx

Question 17

What separates the nasopharynx and the oropharynx when swallowing?

Answer 17

Passavant’s ridge/palatopharyngeal sphincter

Question 18

What are the actions of palatopharyngeus?

Answer 18

• elevates the pharynx and larynx
• draws the soft palate downwards
• brings palatopharyngeal arches backwards
• separates oral cavity from the pharynx

Question 19

Name the pharyngeal elevator muscles

Answer 19

• palatopharyngeus
• stylopharyngeus
• salpingopharyngeus

Question 20

Describe the anatomical position of stylopharyngeus

Answer 20

• extends from styloid process
• passes between superior and middle pharyngeal constrictors
• fan into the internal pharyngeal surface

Question 21

Describe the anatomical position of salpingopharyngeus

Answer 21

• descends into the pharynx from torus tubarius

- opens the auditory tube during swallowing

Question 22

Describe the functions of the pharyngeal muscles

Answer 22

• elevators pull pharynx superiorly and receives bolus
• pharyngeal constrictors compresses the lumen of pharynx and push bolus towards oesophagus
• inferior pharyngeal constrictor has cricopharyngeal sphincter that prevents air being drawn into the stomach during inhalation

Question 23

Describe the arterial supply of the pharynx

Answer 23

• upper pharynx: branches of external carotid artery

- lower pharynx: branches of inferior thyroid artery of thyrocervical trunk of subclavian artery

Question 24

Describe the venous drainage of the pharynx

Answer 24

pterygoid plexus that converges on facial and internal jugular veins

Question 25

Describe lymphatic drainage of the pharynx

Answer 25

• retropharyngeal nodes
• paratracheal nodes
• infrahyoid nodes
• all drain to deep cervical nodes
• palatine tonsils drain to jugulodigastric

Question 26

Describe the sensory supply of the pharynx

Answer 26

Maxillary division of trigeminal nerve:
- nasopharynx

Glossophryngeal nerve: oropharynx, palatine tonsils, inferior surface of soft palate and posterior 1/3rd of tongue

Vagus nerve:

• laryngopharynx
• vallecula
• epiglottis

Question 27

Describe the sequence of swallowing

Answer 27

• bolus pushed towards back of oral cavity towards palate by mylohyoid and tongue muscles
• palatoglossal and palatopharyngeal arches relax and move laterally
• tongue pulled upwards and backwards to tip bolus through oropharyngeal isthmus and into pharynx by styloglossus
• soft palate stretched and elevated by tensor veli palatini, levator veli palatini
• elevated soft palate and passavant’s ridge separate nasopharynx from oropharynx by superior pharyngeal constrictor
• pharynx is elevated by pharyngeal elevators
• laryngeal inlet closed
• bolus pushed towards oesophagus by pharyngeal constrictors

Question 28

Describe how infant anatomy is different from that of an adult

Answer 28

• omega shaped epiglottis
• tongue with central groove
• fat pads for generation of intra-oral suction
• close proximity of soft palate and epiglottis
• elevated larynx that is tucked under epitglottis