Session 5: The Airway and its Relations

Question 1

What type of epithelium lines the conchae?

Answer 1

Respiratory Epithelium
Increases SA for warming + humidifying inspired air + traps pathogens
(conchae AKA turbinate bones)

Question 2

What name is given to the gaps between conchae?

Answer 2

Meati (superior, middle, inferior)

Question 3

What is the name of the space superior to the superior concha?

Answer 3

Sphenoethmoidal Recess

Question 4

Which sinus drains into the sphenoethmoidal recess?

Answer 4

Sphenoidal Sinus

Question 5

What action does the epiglottis perform to close off the laryngeal inlet?

Answer 5

Retroflexion

Question 6

What is the role of the pharyngotympanic tube (Eustachian tube)?

Answer 6

Equalises the pressure on either side of the tympanic membrane by allowing a connection between the middle ear and the nasopharynx

Question 7

Where are the ethmoidal cells found?

Answer 7

Medial to the orbit

Question 8

What is the clinical relevance of the sphenoid sinus in relation to the pituitary gland?

Answer 8

It is penetrated in transphenoidal hypophysectomy

Question 9

What significant structure is found inferior to the middle nasal concha?

Answer 9

Semilunar Hiatus

Question 10

Where does the sphenoidal sinus drain?

Answer 10

Into the sphenoethmoidal recess

Question 11

What are the three parts of the ethmoidal air cells and where do each of them drain?

Answer 11

Anterior, middle + posterior ethmoidal air cells
Posterior: lateral wall of superior meatus
Middle: ethmoidal bulla
Anterior: top of the semilunar hiatus via the frontonasal duct with the drainage of the frontal sinus

Question 12

Where does the maxillary sinus drain?

Answer 12

To the bottom of the semilunar hiatus

Question 13

Where does the nasolacrimal duct drain and what is its role?

Answer 13

To the lateral wall of the inferior meatus

It drains tears from the lacrimal sac to the nasal cavity

Question 14

State 3 roles of the sinuses in the skull.

Answer 14

Make the skull lighter
Provide crumple zone for the brain
Increase projection of the voice

Question 15

What are the mastoid air cells and describe its connection with the middle ear.

Answer 15

Small sinuses within the mastoid part of the temporal bone
Mastoid air cells communicate with the middle ear via the aditus ad antrum + the mastoid antrum
= a possible route for infection of the middle ear

Question 16

What is the name given to the thin plate of bone that forms the roof of the tympanic cavity?

Answer 16

Tegmen tympani

Question 17

Through which membrane is a cricothyroidotomy performed?

Answer 17

Cricothyroid ligament

Question 18

What important cartilage is found attached to the top of the cricoid cartilage? What object is the cricoid cartilage likened to?

Answer 18

Arytenoid cartilage
Signet ring (broad posteriorly, thinner anteriorly)

Question 19

What effect does tilting the thyroid cartilage forwards have on the vocal folds? Which muscles perform this action?

Answer 19

Puts tension on the vocal folds

Cricothyroid muscles

Question 20

What are the two parts of the cricoid cartilage?

Answer 20

Lamina

Arch

Question 21

What two things do the cricoid cartilage articulate with?

Answer 21

Arytenoid cartilage

Inferior horns of the thyroid cartilage

Question 22

What name is given to the protrusion between the laminae of the thyroid cartilage and what notches are found above and below this point?

Answer 22

Laryngeal prominence

Superior + inferior thyroid notch

Question 23

What two bits of cartilage are found on top of the arytenoid cartilage?

Answer 23

Corniculate + Cuneiform Cartilage

Question 24

What are the two folds in the mucosa in the laryngeal inlet and how are they arranged?

Answer 24

Vestibular Fold (false vocal fold)  
Vocal Fold (true vocal fold)  
Vestibular folds are lateral to the vocal folds

Question 25

What membranous outpouching is formed between the vestibular and vocal folds?

Answer 25

Laryngeal ventricle and laryngeal saccule

Question 26

What is the name given to the opening between the vocal folds?

Answer 26

Rima glottidis

Question 27

Which muscles are attached only to the arytenoids?

Answer 27

Transverse + Oblique Arytenoid muscles

Question 28

Which muscles are involved in abducting and adducting the vocal folds?

Answer 28

Posterior cricoarytenoid muscle: abduction | Lateral cricoarytenoid muscle: adduction

Question 29

Which nerve provides sensory and motor control of the larynx?

Answer 29

Vagus Nerve

Question 30

What are the different laryngeal branches of the vagus nerve and what do these branches do?

Answer 30

Superior Laryngeal Nerve: separates into internal + external laryngeal Internal Laryngeal: sensory above the vocal folds External Laryngeal: motor to cricothyroid muscles Recurrent Laryngeal: sensory below the vocal folds + motor to all other muscles of the larynx

Question 31

Which arteries do the superior and recurrent laryngeal nerves run alongside?

Answer 31

Superior: Superior thyroid artery Recurrent: Inferior thyroid artery

Question 32

Why is the left recurrent laryngeal nerve more susceptible to damage by bronchial/oesophageal tumours and swollen mediastinal lymph nodes than the right recurrent laryngeal nerve?

Answer 32

Left recurrent laryngeal nerve branches off the vagus much more inferiorly than the right so has more of its length that is near the bronchus, oesophagus + mediastinal lymph nodes

Question 33

What are the common changes that occur during sneezing and coughing?

Answer 33

Inspiration Closed glottis + contraction of abdominal muscles Increase in intrathoracic pressure Sudden abduction of the vocal folds to release the intrathoracic pressure

Question 34

What is the difference in the oropharyngeal isthmus in coughing compared to sneezing?

Answer 34

In coughing, the oropharyngeal isthmus is open | When sneezing, it is closed

Question 35

Which afferents take information from laryngeal receptors to trigger the cough reflex?

Answer 35

Vagus

Question 36

Which afferents take information from laryngeal receptors totrigger the sneeze reflex?

Answer 36

Maxillary branch of the Trigeminal nerve

Question 37

How is the movement of the soft palate different in cough reflex compared to a sneeze?

Answer 37

Cough: soft palate is raised + tensed against the posterior wall of the pharynx Sneeze: soft palate is depressed against the tongue

Question 38

The soft palate is depressed against the tongue when sneezing to prevent the release of the pressure through the mouth. Which nerve and muscles are involved in this?

Answer 38

Vagus – palatoglossus/ palatopharyngeus

Question 39

What happens to the vocal folds when sneezing and coughing?

Answer 39

They abduct

Question 40

The soft palate is raised and tensed against the posterior wall of the pharynx when coughing. Which muscles are involved in this action and which nerves innervate these muscles?

Answer 40

Tensor veli palatini (mandibular of trigeminal (V3)) Levator veli palatini (X) Superior constrictor (X)

Question 41

What and where is the vallecula?

Answer 41

Behind the root of the tongue between the folds in the throat Serve as spit traps, saliva is temporarily held in the valleculae to prevent initiation of the swallowing reflex

Question 42

What is the principle function of the larynx?

Answer 42

Protect airways from ingested food (valve) | Phonation

Question 43

Describe innervation of the upper airways

Answer 43

Olfactory nerve- Olfaction Trigeminal nerve: V1 (anterior region), V2 (posterior region) Facial nerve- glands Sympathetic nerves (from T1): vascular smooth muscle

Question 44

Describe the structure of the larynx

Answer 44

Hollow | Composed of cartilages, membrane + muscles

Question 45

What would a lesion in the vagus nerve, internal laryngeal, external laryngeal and recurrent laryngeal cause?

Answer 45

Vagus: Complete paralysis Internal: Loss of sensation above vocal folds External: Paralysis of cricothyroid Recurrent: Paralysis of all muscles of larynx except cricothyroid + loss of sensation below vocal folds

Question 46

What procedure may be associated with damage to the superior and recurrent laryngeal nerves?

Answer 46

Thyroidectomy

Question 47

Name 4 protective mechanisms for the airway

Answer 47

Swallowing Gag reflex Sneezing Coughing

Question 48

What does the facial nerve provide motor innervation too?

Answer 48

Muscles of facial expression, stapedius, digastric (posterior belly), stylohyoid

Question 49

What does the facial nerve provide sensory innervation too?

Answer 49

Taste (ant. 2/3 of tongue) Parasympathetic (lacrimal glands, mucous glands of nasal cavity, hand + soft palates, sublingual + submandibular glands) General sensation from external acoustic meatus + deeper parts of auricle

Question 50

What is found superior to mastoid air cells? What is the significance of this?

Answer 50

Middle cranial fossa | Infections can erode the bone into the cranial cavity to cause intracranial infection