Session 7 - The Nose

Question 1

Describe the external structure of the external nose:

Answer 1

Anterior superior 1/3rd is bony - nasal bone, frontal part of maxilla, nasal part of frontal bone
Inferior section is made of cartilage - septal cartilage, 2 lateral cartilages and 2 alar cartilages

Question 2

Describe the structure of the nasal septum:

Answer 2

Anterior portion is cartilaginous - septal cartilage
Central portion - perpendicular plate of ethmoid bone
Posterior portion - vomer bone

Question 3

Describe the internal structure of the external nose:

Answer 3

Skin extends into the vestibule
Thick coarse hairs which are moist help to filter - remove dust particles
Skin extends beyond hairs and then ends and becomes a mucous membrane.

Question 4

What is a septal haematoma?

Answer 4

After trauma to the nose ?blood collects and the cartilage is no longer supplied with oxygenated blood. If this continues the cartilage will necrose and a saddle nose deformity will occur.

Question 5

What are some of the complications fracture to the external nose?

Answer 5

Rhinorrhea - fracture of cribiform plate can result in a tearing of the meninges and leakage of CSF
Anosmia - fracture of cribiform plate can damage olfactory nerve/bulb resulting in lack of smell
Saddle nose deformity
Deformed or deviated septum - nasal breathing affected -? Snoring increased risk of resp infections?

Question 6

Describe the structure of the nasal cavity:

Answer 6

Entrance - nares 
Exit - choanae - into nasopharynx 
Roof - cribiform plate of ethmoid bone 
Floor - palatal shelf of maxilla and palatine bone 
Lateral wall - chonchae 
Medial wall - bony/cartilaginous septum

Question 7

What are the names of the 4 spaces between conchae?

Answer 7

Sphenoidethmoidal recess - above superior conchae
Superior meatus - between superior and middle conchae
Middle meatus - between middle and inferior conchae
Inferior meatus - below inferior conchae

Question 8

What would you find in the sphenoethmoidal recess?

Answer 8

Mucous membrane is adapted for olfaction.

Axonal processes pass the cribiform plate then form the olfactory bulb.

Question 9

What would you find in the superior meatus?

Answer 9

Exit for drainage of the posterior ethmoid sinus

Question 10

What would you find in the middle meatus?

Answer 10

Drainage for the frontal air sinus anteriorly
Drainage for the maxillary air sinus posteriorly
Connected by a semi lunar hiatus which may allow movement of infection between sinuses.
Also drainage for the anterior ethmoidal air sinus.

Question 11

What would you find in the inferior meatus?

Answer 11

Drainage for the nasolacrimal duct.

Question 12

What lymphoid tissue is found in the nasopharynx and how does it differ in adults and children?

Answer 12

Adenoids - tonsils

They are larger in children and ?can result in a blockage of the Eustachian tube.

Question 13

Describe the blood supply of the nose:

Answer 13

Supply to medial and lateral nasal walls by the maxillary (ECA), facial artery (ECA) and opthalmic artery (ICA)
Drainage is via cavernous sinus, facial artery and pterygoid plexus.

Question 14

What is Kiesselbach’s area?

Answer 14

Area in the anterior portion of the nose where many arteries anastomose. This means if there is damage to this area there can be profuse bleeding. This is usually the cause of nose bleeds.

Question 15

Describe the nervous supply to the nose:

Answer 15

Mucous membranes - Maxillary and opthalmic branches of the trigeminal nerve.

Question 16

Describe the maxillary sinus:

Answer 16

Roof - floor of the orbit 
Floor - alveolar part of maxillary bone 
Largest of all sinuses 
Present at births and grows in size at around 8 years old 
Opens into middle meatus.

Question 17

Describe the frontal sinus

Answer 17

Not present at birth
Variable in size
Empties into the middle meatus via the frontonasal duct

Question 18

Describe the ethmoidal sinus:

Answer 18

Ethmoidal air cells between the orbit and nasal cavities
Anterior drains into the middle meatus via the infundibulum
Posterior drains in the superior meatus
Centrally drains direct into the middle meatus.

Question 19

Describe the sphenoidal sinus:

Answer 19

Small at birth but enlarges after puberty
In related to the pituitary fossa and middle cranial fossa, cavernous sinus and ICA, posterior cranial fossa and pons, roof of nasopharynx.

Question 20

What bacteria commonly cause sinusitis?

Answer 20

H. Influenzae

S. Pneumoniae

Question 21

How may sinusitis cause visual problems?

Answer 21

Infection in the ethmoidal air sinus can erode into the orbit due to their close relationship. This can result in an infection in the orbit or optic canal.

Question 22

How might tooth extraction cause problems with the sinuses?

Answer 22

If during extraction the root breaks this may then allow communication between the oral cavity and the maxillary sinus. The first two molars roots can reach into the mucous membrane of the maxillary sinus.

Question 23

What are some of the risk factors of epistaxis?

Answer 23

Alcohol 
Trauma 
Tumours
Coagulation defects
Vascular deformities 
Mucosal drying 
NSAIDs 
Infection

Question 24

What are the treatment options for epistaxis?

Answer 24

Pinch bridge of nose just below bony section, lean patient forward.
Cautery - silver nitrate or electro
Tamponade - nasal tampons inserted horizontally into the nasal cavity
Posterior packing - insert catheter into nasal cavity and blow up ballon so that blood cannot enter nasopharynx. Use gauze to pack the entire nasal cavity.
Surgery - ligation of arteries or radiological embolism.

Question 25

What are the functions of the nose?

Answer 25

Olfaction
Filter and humidify air
Respiration
Drain sinuses and naso lacrimal ducts