Nasal Anatomy Flashcards
What is the function of the Nose?
Respiration, Filtration, Humidification, Warming
Olfaction
Reception of sinus and eye secretions
Describe the external nose structure
Dorsum (bridge) root to tip
1/3 bony
2/3 cartilaginous
Nasal bones
Frontal process of maxillae
Nasal part of frontal bones
What is the cartilage of the external nose?
Septal cartilage
2 lateral cartilages
2 alar cartilages (hold nostrils open)
Deformity by trauma or fracture
What forms the midline partition of the internal nose?
Septal cartilage
Perpendicular plate of the ethmoid
Vomer
What causes nasal septum deviation?
Trauma
Congenital (bone grows faster than cartilage)
Explain septal haematoma
Septum fracture bleeds
Blood builds under mucosa
This build up of blood strips the mucosa from the cartilage
This haematoma cuts off blood supply to cartilage
Cartilage may become infected or will die
Infection can cause septal abscess
This can drain into sinus and brain
Quite serious
Must be drained
Describe the structure of the inner nose
Lateral walls = turbinates (humidify and warm air)
- Superior
- Middle
- Inferior
- Also meati
Roof- cribriform plate
Floor - hard palate
What is the clinical relevance of the turbinates?
Swelling due to rhinitis or infection
Can block the nose
Usually treated with steroid sprays
Surgery unusual these days
Describe the nasopharynx
Functionally part of the nose
Muco-ciliary lining
Bounded by the: choana (posterior nostrils), sphenoid sinuses, prevertebral fascia and muscle, soft palate
Important contents = Eustachian opening and adenoids
Explain the blood supply to the nose
Sphenopalatine artery - from maxillary branch of the external carotid
- Also Greater Palatine Artery
- Lateral nasal branches of facial artery
- Ethmoid arteries (anterior and posterior) from the internal carotid system
Capillary plexus on mucosal lining of septum- Wittles area (majority of nose bleeds)
What is the clinical name for a nose bleed?
Epistaxis
Explain the nerve supply of the nose
Fibres from neuro-olfactory epithelium -> olfactory nerve
- hyposmia or anosmia via:
- –Trauma
- –Virus
- –Tumour
- –(rhinitis)
Infraorbital nerve (sensory)
- Branch of 5th cranial
- Parasthesia in: trauma, iatrogenic damage, tumour
What is Hyposmia
Reduced ability to smell
Describe the sinuses
Air filled
Continuous muco-ciliary lining with nose
1 Frontal
2 Maxillary
2 Ethmoid
1 Sphenoid
Drainage is by natural mucocillary pathways
What is the important relation of the frontal sinus?
Anterior cranial fossa
