9 - Oral cavity, tongue, pharynx

Question 1

What are the muscles of the tongue and how are they innervated?

Answer 1

4 intrinsic - hypoglossal motor 
Extrinsic: 
Genioglossus
Hypoglossus
Styloglossus 
Innervated by hypoglossal motor
AND palatoglossus vagus

Question 2

How is the sensory function of the tongue innervated?

Answer 2

Anterior 2/3:
Sensation: mandibular (V3)
Taste: Facial (VII)
Posterior 1/3:
Sensation and taste: glossopharyngeal (IX)

Question 3

What is the Wharton duct?

Answer 3

Where the submandibular glands insert into, under tongue

Question 4

What is the stenson duct?

Answer 4

Where the parotid gland inserts into

Question 5

What causes salivary gland stones and where are they found?

Answer 5

Dehydration / reduced salivary flow

Found in Wharton duct, submandibular gland

Question 6

What is a peritonsillar abscess?

Answer 6

Infection (can follow from tonsillitis) causing an abscess in surrounding tissue around tonsils
Causes deviated uvula

Question 7

What is the nasopharynx and what does it contain?

Answer 7

Space between base of skull to upper soft palate, nasal cavity is anterior, c1/2 posterior
Contains the pharyngeal tonsil and auditory tube opening

Question 8

What is the oropharynx and what does it contain?

Answer 8

Space between soft palate to the epiglottis
Stops aspiration of food into resp tract
Contains palatine tonsils
Oral cavity is anterior, c2/3 posterior

Question 9

What is the laryngopharynx and what does it contain?

Answer 9

Between hyoid bone and larynx and oesophagus
Both food and air pass through
Contains piriform fossa (recesses at the sides where objects can get stuck)
Larynx is anterior
C4-6 posterior

Question 10

What are the longitudinal muscles and what is their function?

Answer 10

Stylopharyngeus
Palatopharyngeus
Salpingopharngeus
Elevate pharynx and larynx during swallowing

Question 11

What are the attachments and innervation of stylopharyngeus?

Answer 11

O: Styloid process of temporal bone
I: Posterior thyroid cartilage
N: Glossopharyngeal (IX)

Question 12

What are the attachments and innervation of palatopharyngeus?

Answer 12

O: Hard palate
I: Posterior thyroid cartilage
N: Pharyngeal branch of vagus (X)

Question 13

What are the attachments and innervation of salpingopharyngeus?

Answer 13

O: Cartilagenous part of pharyngotympanic tube
I: Merges with palatopharyngeus to insert into posterior thyroid cartilage

Question 14

What are the pharyngeal constrictors, what is their function and what are they innervated by?

Answer 14

Incomplete circles of muscle that constrict the walls of the pharynx when swallowing
Superior, middle and inferior pharyngeal constrictors
Innervated by vagus (X) nerve

Question 15

Describe the structure of the inferior pharyngeal constrictor muscle

Answer 15

2 overlapping muscles - thyropharyngeal and cricopharyngeal

Question 16

What is a pharyngeal pouch?

Answer 16

False diverticulum due to failure of UOS to relax or abnormal timing of swallowing, food can collect here

Question 17

How do pharyngeal pouches arise in the inferior pharyngeal constrictor muscle?

Answer 17

Structural weakness at overlap of thyropharyngeal and cricopharyngeal muscles
High pressure in laryngopharynx due to abnormal swallowing
Weakness at overlap produces outpouching

Question 18

How is the pharynx innervated?

Answer 18

Motor - Vagus (X) for all muscles except stylopharyngeus (glossopharyngeal IX)
Sensory: Nasopharynx maxillary (V2) 
Oropharynx glossopharyngeal (IX)
Laryngopharynx vagus (x)

Question 19

What are the phases of swallowing?

Answer 19

Oral
Pharyngeal
Oesophageal

Question 20

Describe the oral phase of swallowing

Answer 20

Voluntary
Preparatory phase, bolus made due to saliva and mechanical break down from teeth
Bolus compressed against palate and pushed into oropharynx by tongue and soft palate

Question 21

What cranial nerve is associated with the oral phase of swallowing?

Answer 21

Hypoglossal (XII) innervates muscles of tongue

Question 22

Describe the pharyngeal phase of swallowing

Answer 22

Involuntary
Tongue pushed against hard palate so food can’t re-enter mouth
Soft palate elevated, nasopharynx sealed (V3 and X) opening pharyngotympanic tube
Suprahyoid (V3, VII, XII) and longitudinal (IX, X) muscles shorten, larynx is elevated and sealed off by vocal cords, pharynx widens and shortens to receive bolus
Elevated hyoid causes epiglottis to close over larynx
Peristalsis moves bolus down pharynx
UOS relaxes

Question 23

Describe the oesophageal phase of swallowing

Answer 23

Involuntary
Bolus propelled down by striated muscle (recurrent laryngeal X)
Propelled by smooth muscle (X)
Peristalsis and relaxing of LOS push bolus through to stomach

Question 24

If a stroke has caused dysphagia, will solids or liquids be harder to swallow?

Answer 24

Fluids, as bolus is larger requires less precise control than fluids

Question 25

What are the symptoms of dysphagia?

Answer 25

``` Coughing/chocking Drooling (can't swallow saliva) Recurrent pneumonia Change in voice Nasal regurg (soft palate not going up) ```

Question 26

What are the symptoms of glossopharyngeal (IX) and vagus (X) nerve damage?

Answer 26

``` Absent gag reflex (loss of sensory from IX) Uvula deviated away from lesion Dysphagia Taste lost on posterior 1/3 of tongue Oropharynx loss of sensation ```

Question 27

What causes damage to glossopharyngeal (IX) and vagus (X) nerves?

Answer 27

Medullary infarct | Jugular foramen fracture

Question 28

What are the symptoms of hypoglossal (XII) nerve damage?

Answer 28

Wasted tongue Tongue deviation towards lesion Fasiculations (twitch)