Lecture 13 - Nose and paranasal sinuses

Question 1

Functions of the nose

Answer 1

• Smell
• Route for inspired air
• Filters inspired air - raps particles in nasal hair and mucous
• Turbulent air flow
• Humidifies and moistens inspired air
• Resonating chamber for speech

Question 2

Nasal cavity lining

Answer 2

Psuedostratified columnar cells with goblet cells

Question 3

Vestibule

Answer 3

Anterior part of nose before conchae lined with skin containing sebaceous and sweat glands and nasal hair.

Filters inspire air

Question 4

Boundaries of the nasal cavity

Answer 4

Roof - anterior crania fossa where the cribriform plate is

Floor - Hard palate

Lateral walls - conchae on ethmoid bone

Medial - nasal septum of the ethmoid bone and septal cartilage

Question 5

Conchae

Answer 5

Bony projections on the lateral wall of the nasal cavity covered by respiratory mucosa

• Superior
• Middle
• Inferior

Question 6

Meatuses

Answer 6

Gaps between conchae

• superior
• middle
• inferior

Question 7

Runny nose

Answer 7

Nose runs due to tears running into the nasal cavity from the lacrimal ducts

Question 8

Openings under the meatuses

Answer 8

Allow drainage of the paranasal air sinuses especially under the middle meatus

Drainage of nasolarimal duct into the nasal cavity

Question 9

Septal haematoma

Answer 9

Septal cartilage is avascular and receives blood from the septal perichondrium

1. Trauma can cause damage to the perichondrium
2. Tear blood vessels
3. Blood accumulates sub-perichondrium forming a septal haematoma

Question 10

Saddle nose deformity

Answer 10

Untreated septal haematoma leads to avascular necrosis of septum cartilage

Get saddling of nasal dorsum

Question 11

Complication of septal haemoatoma

Answer 11

Can get infection in the haematoma forming a septal abscess

Increasing chance of avascular necrosis

Question 12

Innervation to nose and nasal cavity

Answer 12

General sensation - trigeminal nerve

Va - vestibule
Vb - conchae and nasopharynx

Question 13

Olfactory mucous membrane

Answer 13

Contains olfactory receptor neurones - CN I

Question 14

Respiratory mucous membrane

Answer 14

Psuedostratified columnar ciliated epithelium rinch in goblet cells

• Filters - mucous and cilia
• Humidifies - watery secretions
• Warms - vascular

Question 15

Nasal polyp

Answer 15

Benign fleshy accumulation of respiratory mucosa

• Normally bilateral
• Commonly seen in under 40 yr olds

Symptoms:

• Decreased smell and taste
• Blocked nose and watery rhinorroea
• Yellow or pale lump in nasal cavity, felshy and reddened
• Post nasal drip
• Tickly cough as polyp drips into nasopharynx onto larynx

More concerning if unilateral or blood secretions as may be tumour

Question 16

Rhinitis

Answer 16

Inflammation of the nasal mucosal lining

Causes:

• rhinorroea
• sneezing
• post-nasal dripping
• nasal congestion
• nasal irritation

Question 17

Common causes of rhinitis

Answer 17

Simple acute infective rhinitis - viral e.g. common cold

Allergen e.g. pollen or house dust

Question 18

Epitaxis

Answer 18

Nose bleed

Question 19

Blood supply to nasal cavity

Answer 19

From opthalmic (ethmoidal) and maxillary artery (sphenopalatine and greater palatine)

Anastomose in anterior septum in Kiesselbach’s plexus

Question 20

Venous drainage of nasal cavity

Answer 20

Pterygoid venous plexus

Cavernous sinus

Facial vein

Question 21

Paranasal air sinuses

Answer 21

Air filled spaces that are extensions of the nasal cavity lines with respiratory mucosa - ciliated and secrete mucous

Question 22

4 Paranasal air sinuses

Answer 22

Frontal
Ethmoidal
Sphenoid
Maxillary

Question 23

Roleof paranasal air sinuses

Answer 23

• Warm and humidify inspired air

- Reduce weight of skull

Question 24

Ostia

Answer 24

Small channels that allow the drainage of the paranasal air sinuses into a meatus of the nasal cavity

Question 25

Sinusistis

Answer 25

Inflammation of the mucosal lining of the paranasal air sinuses and nasal cavity due to infection Maxillary most commonly affected

Question 26

Innervation of the paranasal air sinuses

Answer 26

Trigeminal nerve Frontal, ethmoidal and sphenois - Va Maxillary - Vb

Question 27

Presentation of acute sinisitis

Answer 27

``` Blocked nose Rhinorrhoea Pyrexia Recent URTI Headache and facial pain ```

Question 28

Pathophysiology of acute sinisitis

Answer 28

1. Primary infection causes decreases cilia function, oedema of the mucosa and ostia and increased nasal secretions 2. Drainage from sinus impeded 3. Stagnant secretions in sinus - breeding ground for bacteria

Question 29

Why is the maxillary sinus most commonly affected?

Answer 29

Drainage is higher up into the nasal cavity so needs to work against gravity

Question 30

COmmon bacteria in acute sinistis

Answer 30

Strep pneumoniae Haemophilus influenzae Moraxella Catarrhalis