Session 7 - The Nose Flashcards
(25 cards)
Describe the external structure of the external nose:
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
Describe the structure of the nasal septum:
Anterior portion is cartilaginous - septal cartilage
Central portion - perpendicular plate of ethmoid bone
Posterior portion - vomer bone
Describe the internal structure of the external nose:
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.
What is a septal haematoma?
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.
What are some of the complications fracture to the external nose?
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?
Describe the structure of the nasal cavity:
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
What are the names of the 4 spaces between conchae?
Sphenoidethmoidal recess - above superior conchae
Superior meatus - between superior and middle conchae
Middle meatus - between middle and inferior conchae
Inferior meatus - below inferior conchae
What would you find in the sphenoethmoidal recess?
Mucous membrane is adapted for olfaction.
Axonal processes pass the cribiform plate then form the olfactory bulb.
What would you find in the superior meatus?
Exit for drainage of the posterior ethmoid sinus
What would you find in the middle meatus?
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.
What would you find in the inferior meatus?
Drainage for the nasolacrimal duct.
What lymphoid tissue is found in the nasopharynx and how does it differ in adults and children?
Adenoids - tonsils
They are larger in children and ?can result in a blockage of the Eustachian tube.
Describe the blood supply of the nose:
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.
What is Kiesselbach’s area?
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.
Describe the nervous supply to the nose:
Mucous membranes - Maxillary and opthalmic branches of the trigeminal nerve.
Describe the maxillary sinus:
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.
Describe the frontal sinus
Not present at birth
Variable in size
Empties into the middle meatus via the frontonasal duct
Describe the ethmoidal sinus:
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.
Describe the sphenoidal sinus:
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.
What bacteria commonly cause sinusitis?
H. Influenzae
S. Pneumoniae
How may sinusitis cause visual problems?
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.
How might tooth extraction cause problems with the sinuses?
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.
What are some of the risk factors of epistaxis?
Alcohol Trauma Tumours Coagulation defects Vascular deformities Mucosal drying NSAIDs Infection
What are the treatment options for epistaxis?
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.
