Nasal cavity, paranasal sinuses and pharynx

Question 1

septal haematoma

Answer 1

• septal cartilage relies on overlying perichondrium for its blood supply
• a haematoma can lift the perichondrium away from the cartilage ,starving it of its blood supply
• if this is not drained quickly this can result in spatial cartilage necrosis causing a saddle shaped deformity to the external nose

Question 2

nasal cavity blood supply

Answer 2

• rich blood supply originating from internal and external carotid arteries
• epistaxis can cause significant blood loss most likely to occur from little’s area

Question 3

venous drainage

Answer 3

generally follows the arteries

connected to the cavernous sinus so infection in the danger triangle can result in cavernous sinus thrombosis

Question 4

nerve supply

Answer 4

special sensation 
-smell 
-olfactory nerves
general sensation 
-nasopalatine nerve(maxillary nerve)
-nasociliary nerve(ophthalmic nerve)
external skin sensation
-trigeminal nerve

Question 5

clinical relevance

Answer 5

cribriform plate fracture can disrupt the olfactory nerve branch sleading to anosmia.casn also provide a pathway for CSF to leak causing CSF rhinorrhoea

Question 6

paranasal sinuses

Answer 6

• paired air-filled spaces
• named according to the bone in which they are located
• lined by pseudo stratified ciliated epithelium with mucous-secreting goblet cells

Question 7

paranasal sinuses

Answer 7

maxillary sinus

-uphill drainage so commonly infected -sinusitis

Question 8

transphenoidal surgery

Answer 8

• access to the pituitary gland through the sphenoid sinus

- avoid the need for craniotomy for a mid-line structure

Question 9

pharynx

Answer 9

• muscular tube that connects the nasal and oral cavities with the larynx and oesophagus
• begins at the base of the skull and ends at the cricoid cartilage (C6)

Question 10

pharynx muscles

Answer 10

-all innervated by the vagus nerve except the stylopharyngess which is innervated by the glossopharyngeal nerve

Question 11

Nasopharynx clinical relevance

Answer 11

• Eustachian tube connects the nasopharynx to the middle ear
• adenoids are lymphoid tissue that increase in size secondary to infection
• enlargement can obstruct ET drainage leading to glue ear in children
• a unilateral middle ear effusion in an adult should be investigated
• adenoid hypertrophy can block the nasopharynx resulting in mouth breathing

Question 12

oropharynx

Answer 12

contains:
-posterior 1/3 of tongue 
-lingual tonsils 
-palatine tonsils 
sensory innervation from the glossopharyngeal nerve via pharyngeal plexus

Question 13

oropharynx clinical relevance

Answer 13

tonsilitis 
common infection of the tonsils 
quinsy 
peritonsillar abcess
complication of bacterial tonsillitis

Question 14

laryngopharynx

Answer 14

• superior border of epiglottis to inferior border of cricoid cartilage
• continuous with oesophagus
• piriform fossa is a deep recess anterolateral to the larynx .sharp ingested foreign bodies may lodge here
• sensory innveration by vagus nerve via internal branch of superior laryngeal nerve

Question 15

laryngopharynx:pharyngeal pouch

Answer 15

potential gap between the upper oblique fibres fibres and lower transverse fibres of inferior constrictor
the submucosa and mucosa of the pharynx may herniate into this space forming a pouch
this causes halitosis, dysphagia and cachexia
-spillage into the larynx can cause aspiration

Question 16

deglutition(swallowing)

Answer 16

3 phases
1-voluntary chewing and pushing food bolus into oropharynx
2-involuntary -soft palate seals off nasopharynx,larynx elevated and pulled forward, widens pharynx
3-involuntary-sequential contraction of pharyngeal constrictors causes peristalsis into oesophagus for semi-solid or solid material.liquids may shoot down oesophagus passively