Nose Flashcards
What are teh fucntions of the nose and nasal cavity
Sense of smell
Provides a route for inspired air
Filters inspired air- trapping particles in nasal hair or mucous
Moistens (humidifies) and warms inspired air
Resonating chamber for speech - eg changes when have a cold voice changes
Describe the external nose
Ss
Why is the nasal bone psusceptible to fracture
Nasal bone very commonly fractured
At first very swollen. Send hoe with pan killers. Bring back in a week to review shape of nose when swelling has gone down. Concern if there is an obstruction to breathing through both nostrils.
What is a vestibule
Vestibule is lined with skin containing sebaceous/ sweat glands and hair
Inspired air enters via vestibule (of external nose)
Assists in filtering of inspired air- trapping particles in nasal hair
Hair is important for fi2ltering of hair before it enters nasal cavity???
What are the brounaris of the nasa cavity
Floor: hard palate
Medial wall: nasal septum
Lateral: irregular…
Roof: sphenoid bone, ethmoid bone, frontal bone, nasal bone
What are the concha
Lateral wall is Irregular Due to Presence of Bony Projections Bony projections (conchae) • Superior • Middle • Inferior
- Slows airflow by causing turbulence of airflow
- Increases surface area over which air passes
Shelf like protections - have meatuses underneath them
Increase teh SA over which air will pass.
How will the speed of air chanegs as it passes though
Air going from small space to big - speed will slow down - as it goes from vestibule to proper nasal cavity. CSA gets bigger, as it reaches back of cavity - gets narrow there so speed pickes up
Mucosa will help to filter and moisten the air. Allows time to modify the air befor it exits into nasopharynx
Why are there openings under the meatuses
- Openings under the meatuses allow for drainage of
- Paranasal air sinuses into nasal cavity
- Nasolacrimal duct into nasal cavity
Describe the osteology
Ss
Describe the nasa septum
2 halves separated by septalcartilage - gives scaffolding to shape of bone . Punch to the face - can fracture nasal bone but an also bent/bake theseptal cartilage
What is a septal haematoma
• Cartilage of nasal septum receives blood supply from overlying perichondrium
• Injury to nose can buckle septum and shears blood vessels
• Blood accumulates sub perichondrium..depriving underlying cartilage of its blood supply
• Septal Haematoma
Bleeding occurs between cartilage and overlying perichondrium. Can lead to avascular necrosis. Can share and not heal very well
What is a saddle nose deformity
• Untreated septal haematoma leads to
avascular necrosis of cartilaginous septum
– saddling of nasal dorsum - saddle nose deformity)
• Can also develop infection in the collecting haematoma
– Septal abscess formation further increases likelihood of avascular necrosis of septum
Always examine for septal haematomas in patients presenting with nasal injury
Need to drain the blood - then need to tamponade perichondrium against the cartilage.
Can also be an are for bacteria to collect - reason to drain it åç
Describe the innervation to the nasa cavity
CN v ss
Describe teh mucous membranes
• specialised Olfactory mucous membrane housing olfactory receptor neurones – Olfaction (smell): CN I • Respiratory mucous membrane – Pseudostratified columnar ciliated epithelium rich in goblet cells – Filters (mucous/cilia - Mucocilliary escalatory - waft it) – Humidifies (watery secretions) – Warms (rich blood supply)
What is a nasal polym ad what are the symptoms
• Usually bilateral: common (>40 years)
• Pale or yellow in appearance/fleshy and reddened, Not very tender
• Symptoms include
– Blocked nose and watery rhinorrhoea – Post-nasal drip
– Decreased smell and reduced taste
– Unilateral polyp +/- blood-tinged secretion may suggest tumour
- snorting due to obstruction of air flow
Can drip - chronic runny nose. Can run down the back - tickle - chronic cough
What is rhinitis
Rhinitis: an inflammation of the nasal mucosal lining
• Many causes, all lead to similar symptoms
– Nasal congestion
– ·҇Rhinorrhoaea
– Sneezing
– Nasal irritation
– Postnasal drip
• Common causes
– Simple acute infective rhinitis (viral- the common cold!)
– Allergic rhinitis
Describe teh blood supply and anterior nose bleed
Rich Blood Supply to Nasal Mucosa Allow for warming and humidification of inspired air
• Mucosa and blood vessels easily injured
– Nose bleed (epistaxis)
• Arterial supply to nasal cavity arises from branches of ophthalmic artery and maxillary artery
– Arterial anastomoses in anterior septum (Kiesselachs plexus). Anterior nose bleed
• Most common source of bleeding in epistaxis
• Easily treatable with simple first aid measure (pinching noise)
Describe the venous drainageto the nasalcavity
• Venous drainage from nasal cavity into pterygoid venous plexus (also drainage to cavernous sinus and
facial vein)
Describe posterior nose bleeds
Bleeding from the sphenopalatine artery (branch of maxillary a) is source for small minority of nosebleeds Potentially more serious and more difficult to treat (not easily reachable to tamponade)
What are the paranasal sinuses and their functions
• Air filled spaces that are extensions of nasal cavity
– Rudimentary or absent at birth - get bigger as get older
• Lined with respiratory muscosa (thus are also ciliated and secrete mucous)
• Named according to bone in which they are found - 4 pairs
Describe the location of the sinuses
Important anatomical relations of the paranasal sinuses include the nasal cavity, orbit and anterior cranial fossa
Roots of upper teeth can sometimes project in maxillary sinus - Sometimes fetal abscess can lead to maxillary sinusitis
General Sensory innervation is from branches of CN V
• Frontal, ethmoidal and sphenoid - Va
• Maxillary - Vb
What is acute sinusitis and the symptoms
Symptomatic Inflammation of Mucosal Lining of Nasal Cavity and Paranasal Air sinuses
• Often secondary to viral infection of nasal cavity
– Symptoms typically peak early but resolve gradually (last <10 days)
• Clinical diagnosis (i.e. based on history and examination)
– Recent URTI
– Blocked nose and rhinorrhoea +/- green/ yellow discharge
– Pyrexia
– Headache/ facial pain (in area of affected sinus)
• Worse on leaning forward
• Self-limiting: treatment is symptomatic (e.g. analgesics, antipyretics, steam inhalation)
What can cause acute sinusitis
• Primary infection (e.g. rhinitis) leads to reduced ciliary function,oedema of nasal mucosa and sinus ostia and increased nasal secretions
• Drainage from sinus is impeded
• Stagnant secretions within the sinus become ideal breading ground for bacteria-secondary infection
• Commonest bacteria include Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis
Mucosal oedema 0 can block off opening. Can get bacterial sinisutus on top of what was already viral
>12 weeks - can become chronic??
When is acute bacterialsinustitsi more likely
Acute bacterial sinusitis more likely if • Symptoms particularly severe at onset • Symptoms >10 days without
improvement (but <4 weeks) • Symptoms that worsen after an initial
improvement (suggesting secondary
bacterial infection)
Describe teh innervation of nasal cavity
• Antero-superior portion (+ most of paranasal
sinuses) supplied by
– Ophthalmic nerve (CN Va ) – [Ophthalmic artery (branches of)]
• Postero-inferior portion (including maxillary sinus)
– Maxillary nerve (CN Vb) – [Maxillary artery (branches of)]
