Nasal cavity, paranasal sinuses and pharynx

Question 1

What does septum do?

Answer 1

Divide nasal cavity

Question 2

What are the three conchae

Answer 2

Superior, middle, inferior

Question 3

Function of external nose

Answer 3

• Airway provision
• Warming and humidification of inspired air
• Filtering of large particulate matter
• Mucous production, trapping, ciliary clearance
• Olfaction
• Alar made of alar cartilage
• Drainage of paranasal sinuses

Question 4

Roof of nasal cavity

Answer 4

Cribriform plate

Question 5

Floor of nasal cavity

Answer 5

Palate

Question 6

Medial wall of nasal cavity

Answer 6

• Nasal septum
• Smooth surface
• Bone (frontal, ethmoid, sphenoid, maxilla, vomer, nasal bone)
• Vomer sits on maxilla
• Septal cartilage
• Cartilage blood supply from perichondrium

Question 7

Septal haematoma

Answer 7

Haematoma causes perichondrium to pull way from cartilage, starving it of blood supply - septal cartilage necrosis

Question 8

What are the four air channels?

Answer 8

Inferior, middle, superior meatus and sphenoid-ethmoidal

Question 9

What do meatus do?

Answer 9

Increases SA in contact with air

Question 10

When you have a blocked nose, why does the feeling switch between sides?

Answer 10

Intermittent switching of conchae to warm air

Question 11

Blood supply to nasal cavity

Answer 11

Facial, ophthalmic and maxillary

Question 12

Where does epistaxis mainly occur?

Answer 12

Little’s area - lots of blood vessels join and end here

Question 13

venous drainage of nasal cavity

Answer 13

• Venous drainage follows arteries
• Drain backwards into cavernous sinus
• Can result in cavernous sinus thrombosis - blood clot puts pressure on CNs and blocks venous drainage = swelling and oedema, diplopia, abnormal eye movements

Question 14

Special sensation nerves to nasal cavity

Answer 14

Smell, olfactory nerves

Question 15

General sensation nerves to nasal cavity

Answer 15

Nasopalatine nerve, nasociliary nerve

Question 16

External skin sensation to nose nerves

Answer 16

Trigeminal

Question 17

What are paranasal sinus?

Answer 17

Paired air-filled spaces

lined with pseudostratidied ciliated epithelium with goblet cells

Question 18

Nasolacrimal ducts

Answer 18

Lacrimal gland produces lacrimal fluid to protect. and lubricate eye. This drains into nasal cavity (at inferior meatus) via nasolacrimal duct, a groove formed by lacrimal bone and frontal process of maxilla

Question 19

What is the pharynx?

Answer 19

• Muscular tube that connects nasal and oral cavities with larynx and oesophagus
• Begins at base of skull and ends at cricoid cartilage (C6)
• Divided into naso/oro/laryngo pharynx

Question 20

Muscles in pharynx

Answer 20

• All innervated by vagus nerve apart from stylopharyngeus which is innervated by glossopharyngeal nerve
• Rich blood supply from lingual, facial and ascending pharyngeal branches of external carotid artery
• Venous drainage via pharyngeal venous plexus, which drains into internal jugular vein

Question 21

What causes mouth breathing?

Answer 21

Adenoid hypertrophy blocking nasopharynx

Question 22

What do Eustachian tube do?

Answer 22

Equalise pressure in middle ear by connecting middle ear to nasopharynx

Question 23

What does oropharynx contain?

Answer 23

Posterior 1/3 of tongue, lingual tonsils, palatine tonsils

Question 24

What is quinsy?

Answer 24

Peritonsilar abcess, complication of bacterial tonsilitis, signs (dysphagia, trismus, hot potato voice), can obstruct airway, needs drainage

Question 25

What is laryngopharynx?

Answer 25

Superior border of epiglottis to inferior border of cricoid cartilage]Continuous with oesophagus

Piriform fossa is deep recess anterolateral to larynx on each side - fish bones get lodged here

Sensory innervation by vagus nerve via internal branch of superior laryngeal nerve

Question 26

What is the pharyngeal pouch?

Answer 26

Potential gap between upper and oblique fibres (thyropharyngeus) and lower transverse fibres (cricopharyngeus) of inferior constrictor

Submucosa and mucosa of pharynx may herniate into space, forming pouch - halitosis, dysphagia and cachexia

Question 27

Stages of swallowing

Answer 27

3 phases: 1) voluntary chewing and pushing food 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