Oral and Nasal Cavities, Pharynx and Larynx

Question 1

Describe the characteristics and extent of the pharynx.

Answer 1

The pharynx is a musculomembranous tube that resembles an inverted cone extending from the skull base to the lower border of the cricoid cartilage (C6,7).

Question 2

How does the pharynx communicate wit the nasal and oral cavities?

Answer 2

via the nasopharynx, oropharynx, and laryngopharynx respectively.

Question 3

Where is the danger (alar) space?

Answer 3

Within the pre vertebral fascia (alar and deep pre-vertebral fascia); covers the anterior surface of transverse processes and bodies of cervical vertebrae

Question 4

Where does the danger (alar) space extend?

Answer 4

Extends from base of skull through posterior mediastinum to diaphragm

Question 5

Where is the retropharyngeal space?

Answer 5

Between buccopharyngeal fascia and superficial pre vertebral fascia (alar fascia); extends between base of skull and superior mediastinum.

Question 6

Why are the ‘true’ retropharyngeal and danger (alar) spaces clinically significant?

Answer 6

They are potential spaces, consisting of loose connective tissue, lying behind the pharynx and proving a possible gateway for spread of infection from there to the thorax.
Infections from the pharynx can spread via the ‘true’ retropharyngeal (e.g. retropharyngeal abscess) and danger (alar) spaces into the posterior mediastinum.

Question 7

At what level does the alar fascia fuse with the pre tracheal (middle) layer of the deep cervical fascia?

Answer 7

below T1 to T6

Question 8

Where do all three pharyngeal constrictors attach?

Answer 8

pharyngeal raphe

Question 9

What attache the superior pharyngeal constrictor muscle to the skull?

Answer 9

the pharyngobasilar fascia

Question 10

Describe the innervation of the pharyngeal muscles.

Answer 10

The pharyngeal muscles, with the exception of stylopharyngeus that is supplied by the glossopharyngeal nerve (CN IX), receive their nerve supply from the pharyngeal plexus

Question 11

Where does the pharyngeal plexus lie?

Answer 11

Lies on the posterior external aspect of the pharynx especially on the middle pharyngeal constrictor muscle.

Question 12

Describe the motor supply to the pharyngeal plexus.

Answer 12

The motor supply to the pharyngeal plexus is from the pharyngeal branch of the vagus nerve (CN X) and the sensory supply is from the pharyngeal branch of the glossopharyngeal nerve (CN IX).

Question 13

What nerves emerge from the jugular foramen?

Answer 13

CN IX, X, XI

Question 14

What arteries does CN IX pass between? At what level?

Answer 14

passes between the external and internal carotid arteries at the level of the stylopharyngeus muscle.

Question 15

What are conchae?

Answer 15

Conchae refer to the bony structures (anatomical term)

Question 16

What are nasal turbinates?

Answer 16

nasal turbinates refer to the bony structures with the overlying tissue/mucosa (clinical term)

Question 17

What is the function of nasal turbinates?

Answer 17

The nasal turbinates are essential for flow, filtration, temperature regulation, and humidification of the inspired air. .

Question 18

Describe hypertrophy of the nasal turbinates.

Answer 18

Hypertrophy of the nasal turbinates, due to allergy or environmental irritation, can result in nasal obstruction.

Question 19

Describe the connections of the pharyngotympanic (auditory/Eustachian) tube.

Answer 19

The pharyngotympanic (auditory/Eustachian) tube connects the middle ear with the nasopharynx (external environment) equalising pressure between these two regions.

Question 20

What tonsils obstruct the flow of air from the nasopharynx?

Answer 20

Enlarged pharyngeal tonsils are known clinically as adenoids q

Question 21

Branches of what arteries supply the nasal cavity?

Answer 21

Branches of the ophthalmic, maxillary, and facial arteries supply different territories of the nasal cavity.

Question 22

What is the blood supply of the nasal mucosa?

Answer 22

The sphenopalatine branch of the maxillary artery predominantly supplies the nasal mucosa

Question 23

What is the blood supply of the interior meatus?

Answer 23

the greater palatine branch of the maxillary artery

Question 24

Describe Kiesselbach’s area/triangle or Little’s area.

Answer 24

A region of the nasal septum where arteries anastomose:
- Anterior ethmoidal
- Sphenopalatine
- Greater palatine
- Septal branch of superior labial artery [branch of facial artery])
This septal region is a common site of epistaxis (nose bleeds).

Question 25

What muscles make up the soft palate?

Answer 25

Essentially the aponeurosis of tensor veli palatine, but levator veli palatini also inserts into that aponeurosis.

Question 26

What are the actions of tensor veil palatine?

Answer 26

Tenses the soft palate and opens mouth of pharyngotympanic membrane tube during swallowing and yawning

Question 27

What are the actions of levator veli palatini?

Answer 27

Elevates soft palate during yawning and swallowing

Question 28

What does the palatoglossal fold (palatoglossus muscle) correspond to?

Answer 28

corresponds to the anterior pillar of the fauces

Question 29

What does the palatopharyngeal fold (palatopharyngeus muscle) correspond to?

Answer 29

corresponds to the posterior pillar of the fauces

Question 30

Describe Waldeyer’s tonsillar ring and what it consists of.

Answer 30

Waldeyer’s tonsillar ring describes the arrangement of mucosa-associated lymphoid tissue in the pharynx
Consists of the :
- Pharyngeal tonsils
- Tubal tonsils
- Palatine tonsils
- Lingual tonsils
The lymphoid tissue provides a defence mechanism against pathogens.

Question 31

Where does the larynx extend?

Answer 31

The larynx extends from the tongue to the trachea

Question 32

What is the larynx used for?

Answer 32

Predominantly used for phonation. It is also an air passage and assists with swallowing by acting as a sphincter to close the laryngeal inlet (aditus).

Question 33

Where can foreign bodies become trapped?

Answer 33

Foreign bodies can be trapped in the piriform fossa (recess).

Question 34

Describe the actions of the cricothyroid muscle?

Answer 34

Tilts the thyroid cartilage anteriorly to lengthen the vocal ligaments (increase tension).

Question 35

Describe the actions if the thyroarytenoid muscle.

Answer 35

Tilts the thyroid cartilage backwards to shorten the vocal ligaments (relaxation).

Question 36

Describe the actions of the posterior cricoarytenoid muscle.

Answer 36

The vocal processes of the arytenoid cartilages rotate laterally that leads to abduction of the vocal ligaments and opening of the rima glottidis. The posterior cricoarytenoid muscle also draws the arytenoid cartilages downwards and laterally on the shoulders of the cricoid lamina, but this movement is not possible on the model.

Question 37

What muscle counteracts lateral movement caused by the posterior cricoarytenoid muscle?

Answer 37

transverse arytenoid muscle

Question 38

What muscles counteracts the rotatory movement of the arytenoid cartilages caused by the posterior cricoarytenoid muscle?

Answer 38

by the contraction of the lateral cricoarytenoid muscle

Question 39

During heavy lifting, what muscles provide closure for the rima glottidis?

Answer 39

the lateral cricoarytenoid muscle and the transverse arytenoid muscle

Question 40

What occurs when the rima glottidis is firmly closed?

Answer 40

With the rima glottidis firmly closed the rise in intra-abdominal pressure cannot push the diaphragm
upwards.

Question 41

Describe the actions of the oblique arytenoid muscle.

Answer 41

Acts as a ‘purse-string’ contributing to laryngeal inlet (aditus) closure.

Question 42

Describe the innervation of the intrinsic muscles of the larynx.

Answer 42

All the intrinsic muscles of the larynx, with the exception of cricothyroid that is supplied by the external branch of the superior laryngeal nerve, are supplied by the recurrent laryngeal nerve.

Question 43

What provides sensation of the larynx above the vocal folds?

Answer 43

Sensation of the larynx above the vocal folds is supplied by the internal branch of the superior laryngeal nerve

Question 44

What provides sensation of the larynx below the vocal folds?

Answer 44

Sensation below is provided by the recurrent laryngeal nerve.

Question 45

What is the function of the cricopharyngeus muscle?

Answer 45

The cricopharyngeus muscle is part of the upper oesophageal sphincter mechanism and prevents air from entering the oesophagus and stomach.