(7.1) The Nose

Question 1

Describe the osteology of the nose.

Answer 1

Bony part posteriorly + Hyaline cartilage part anteriorly
External nose: Nasal Bones + Frontal Bones + Maxillary Bones + Lateral Cartilages + Alar Carilages
Septal part: Nasal Bones + Ethmoid Bone + Vomer Bone + Septal Cartilage

Question 2

Sketch the locations of Paranasal sinuses and describe the drainages of each.

Answer 2

http: //www.aboutcancer.com/paranasal_sinus_cancer.htm
- Sphenoidal Sinus -> Spheno-ethmoidal Recesses
- Ethmoidal Sinuses (posterior part) -> Superior Meatuses
- Ethmoidal Sinuses (middle & anterior parts) -> Middle Meatus
- Frontal Sinuses -> Middle Meatus
- Maxillary Sinuses -> Middle Meatus (need cilia)

Question 3

How may infection of Ethmoidal sinus cause complication?

Answer 3

Ethmoidal sinus lies close to Optic canal, infection may affect Optic Nerve or Opthalmic Artery -> visual problems

Question 4

Why may infection of the Maxillary sinus cause toothache?

Answer 4

Mucosa of Maxillary sinuses & 3 Maxillary Molar teeth are innervated by Superior Alveolar Nerves (br. of CN Viii)

Question 5

What are the functions of Conchae and Meatuses?

Answer 5

Moist + warm + filter air

Question 6

Describe the drainages inside the nasal cavity.

Answer 6

• Spheno-ethmoidal recesses

Question 7

What are the arterial supplies to the nose? Where does nosebleed common occur and what is it called clinically?

Answer 7

• Facial + Opthalmic + Maxillary arteries
• 5 branches anastomose at Kiesselbach’s area anteriorly
• Epistaxis

Question 8

What are the venous drainages of the nose?

Answer 8

• Facial Vein
• Cavernous Sinus
• Pterygoid Plexus

Question 9

Describe the general sensory innervations of the nose.

Answer 9

• Superoanteriorly: Opthalmic N (CN Vi)

- Inferoposteriorly: Maxillary N (CN Vii)

Question 10

What is the special sensory innervation of the nose? Where does it loccate?

Answer 10

Olfactory N (CN I)
Fibres penetrate through Cribiform plate of Ethmoid bone in Spheno-ethmoidal recess

Question 11

What problem may a fracture in Ethmoid Bone cause?

Answer 11

Anosmia, due to fracturing Cribiform plate, where the olfactory nerve fibres locate

Question 12

Suggest some unique similarities between the Olfactory and Optic nerves.

Answer 12

• Lined by meninges (should be called brain tracts)

- Don’t join the brain stem ( brain stem constitutes the bits including and after the midbrain)

Question 13

What type of cancer can commonly cause Anosmia? Where is it commonly located?

Answer 13

Meningioma at the Olfactory groove (where the olfactory bulb sits)

Question 14

Which sinus can be used to access the pituitary gland?

Answer 14

Sphenoidal sinus

Question 15

How may a basilar skull fracture lead to Rhinorrhea?

Answer 15

Basilar fracture at base of skull -> opening between anterior or middle cranial fossa and nasal cavity -> CSF leaks into nose

Question 16

What is inflammation of nasal mucosa called? What are the possible causes?

Answer 16

• Rhinitis
• Infection: Adenovirus / Rhinovirus
• Allergies
• Nasal polyps -> obstuction

Question 17

Why may an infected premolar/molar tooth cause yellow discharge from the nose when bending down?

Answer 17

• Roots of Premolar/Molar teeth project into Maxillary Sinus
• Infection penetrates through bones into Maxillary Sinus
• Pus accumulation in Maxillary sinus -> bending -> drains down Middle Nasal Meatus (e.g. upward drainage) -> yellow discharge