Session 9 B Flashcards
Functions of nose and nasal cavity
Olfaction
Filtering
Humidifying and warming inspired air
Drainage of secretions from paranasal sinuses and nasolacrimal ducts
External nose is predominantly
Cartilaginous, however frontal processes of maxillae and 2 nasal bones form root
Complications of nose injuries
Septal haematoma, septal deviations and nasal bone fractures
Describe Nasal cavity
Extends from nostrils anteriorly (anterior nasal apertures)
To posterior nasal apertures (choanae)
Has a roof, floor and 2 walls
Opens into most superior part of pharynx, Nasopharynx
Medial wall of nasal cavity is formed by
Nasal septum - perpendicular plate of ethmoid bone, septal cartilage and vomer
Cartilaginous portion of septum relies on
Overlying perichondrium for blood supply
Clinical implications of injuries involving nasal septum
-Septal haematoma
-blood collects in space between cartilagenous septum and perichondrium
-Lifts perichondrium off cartilage, stripping away blood supply
- Pressure of accumulating blood causes ischeamia of cartilage
Outcomes of septal haematoma
Must be recognised and drained in timely fashion, irreversible necrosis occurs if not
Saddle deformity- cosmetic distortion of the nose
hence important to inspect nasal septum after any sort of nasal trauma
What are these
Describe the paranasal cavities or sinuses
4 major ones
Maxillary, frontal, ethmoidal and sphenoid
All paired except sphenoid, maxillary is largest
Ethmoidal sinuses collectively consist of the
Anterior, middle and posterior air cells
Describe paranasal sinuses anatomy
Air-filled spaces
Lined with respiratory mucosa (ciliated Pseudostratified columnar with goblet cells)
Communicate with nasal cavity via openings e.g. middle meatus
Obstruction to drainage from a paranasal sinus can lead to
An accumulation of mucosal secretions, development of acute sinusitis
Pain and tenderness over sinus involved, nasal discharge, general systemic upset (fever, feeling unwell)
Causes of sinusitis
Infections of nose (infective rhinitis)
Dental infections (roots of some of the upper teeth lie on floor of maxillary sinus)
4 paranasal air sinuses
What is sinusitis
Inflammation of the lining of the sinuses and can occur following a viral infection of the nasal mucosae
Spreads to involve sinuses
Paranasal sinus infection causes
Mucosal oedema, impedance of ciliary function and increasing mucosal secretions
What can happen if drainage from sinuses become obstructed
Oedema involves openings into nasal cavity
Obstruction combined with increased mucosal secretions leads to a stagnant pool collecting within sinus
Secondarily infected by bacteria
Which sinus is prone to infection
Maxillary sinus- antrum
Location of its opening high on the wall of the nasal cavity
Diagnosis and treatment of sinusitis
History and clinical examination
Self-limiting, treated with simple analgesics, improve within 1-2 weeks
Antibiotics needed if secondary bacterial infection suspected (prolonged, severe symptoms)
Complications from sinusitis
Rare
Ethmoidal sinuses= break through thin medial wall of orbit
Infection spreads to orbit = orbital cellulitis
Potentially sight threatening as may involve optic nerve, track back further to involve intracranial structures
Role of concha and meatuses
Lateral wall of nasal cavity
Medial wall of nasal cavity
What is this
Septal haematoma
Features of nasal bone fracture
Features of blood supply to nasal cavity
rich
Allows humidification and warming
Anastomoses on medial wall is a site of bleeding (Epistaxis)
What are nasal polyps
Features of rhinitis
What are Ostia
Small channels that drain from paranasal cavity into nasal cavity into meatus
Anterior and posterior ethmoid arteries arise from the
Opthalmic artery
Opthalmic artery is a branch of the
Internal carotid artery
Sphenopalatine artery and greater palatine arteries are branches of the
Maxillary artery
Maxillary artery is a branch of the
External carotid
Branches of external carotid artery
Some anatomists like freaking out poor medical students
Nervous supply to nasal cavity
Trigeminal nerve- Opthalmic branch and maxillary branch
Paranasal air sinus innervation
Clinical diagnosis of acute sinusitis
recent URTI
Blocked nose and rhinorrhoea +/- green yellow discharge
Pyrexia
Headache/facial pain worse on leaning forwards
Acute bacterial sinusitis more likely if
Symptoms particularly severe at onset
Symptoms more than 10 days without improvement but less than 4 weeks
Worsen after initial improvement
Most common bacteria for acute bacterial sinusitis
Streptococcus pneumonia, haemophilia influenzae, moraxella catarrhalis
Arteries that are important to know for nose bleeds
Minor treatment of nose bleeds
Pinch in front of the bony bridge of nose and hold for 15-20 mins
Arterial supply to the nasal cavity is mainly from
Branches of the maxillary artery
Origin for most nosebleeds
Little’s area (90%)
10% arise from sphenopalatine artery (can be very problematic as at higher pressure, and posteriorly located, harder to reach)
Causes of nose bleeds
Spontaneously, very minor trauma, underlying systemic causes (abnormal coagulation and connective tissue disorders)
Management of epistaxis includes
Applying simple compression, cauterisation or anterior packing using nasal tampons
Posterior packing or surgical intervention e.g. embolisation, ligation of blood vessels
ABCs closely monitored in severe epistaxis
Steps to confirm correct placement of nasogastric tube
Aspirate to confirm pH is acidic, CXR
NG tube use (not feeding)
Bowel obstruction
Act to drain or empty stomach of excess gas and fluid that is accumulating whilst bowel is obstructed
