Head and Neck II Flashcards
Where does the nasal cavity extend from?
From nares anteriorly to choanae
What are the 3 regions of the nasal cavity?
Olfactory - superiorly
Respiratory
Nasal vestibules - anteriorly and inferiorly
Which bones make up the nasal septum?
Perpendicular plate of ethmoid, vomer, cartilage, nasal septum, crest of maxillary bone and palatine bone
12 bones all together
Perpendicular plate attached directly to vomer bone at middle part of septum
What are the choanae?
Opening at the back of the nose
Allows air to pass through the nose and pass down respiratory tract - once aerated, warmed up and humdified
Where are the meatuses?
Run between superior, middle and inferior choncha
What is the cell lining of the meatuses?
Contain pseudostratified cilated columnar epithelium
Cilia help beat and remove bacteria/unwanted particles
What are the choncha?
Bony structures - shell shaped superior, middle and inferior
What is the alar fibro fatty tissue?
Outer alar margin and sidewall are made of fibro-fatty soft tissue.
What are the cartilages of the nose?
Nasal septum (left + septal processes) Major ala (medial + lateral) Minor ala
What is the crista galli?
Attachment of falx cerebri (dura mater)
Splitting cerebral hemisphere
What does the cribiform plate contain?
Houses olfactory nerves
What is the uncinate process?
Projection of the ethmoid bone
Connection point
Can be attached to either the lateral nasal wall
Superior attachment of the uncinate process determines the drainage pattern of the frontal sinus.
How is the frontonasal sinus drained?
Drains via infundibulum under middle concha
Frontonasal sinus connects frontal sinus to nasal cavity and allows it to drain there
What are the entry ways of the maxillary sinus?
Only one entry point (also exit point)
Uncinate process = opening
Which sinuses open into the middle meatus?
Frontal, maxillary and anterior ethmoidal sinus open into middle meatus
Where does the nasolacrimal duct drain?
Runs down from nasal aperture and opens into inferior meatus
What other structures open into the inferior meatus?
Eustachian tube - allows middle ear to equalise with atmospheric air pressure
What is the function of the paranasal sinuses?
Lightening the weight of the head, humidifying and heating inhaled air, increasing resonance speech
Serves as crumple zone to protect vital structures in event of trauma
What is significant about the sinuses in children?
Poorly developed in children
Describe the frontal sinus
May be multiple
Each w/ frontonasal duct
Drains into middle meatus via frontonasal duct, opens into frontal recess or ethmoidal infundibulum
What are the ethmoidal air sinuses?
Ethmoid bulla and ethmoid air cells - on medial wall of orbit
What are the practical implications of the ethmoid air cells?
Ethmoid air cell infection
If drainage blocked, infections may break through fragile orbital wall
Severe infections can cause blindness as some ethmoidal cells very close to optic canal - transmits optic nerve and opthalmic artery
What is the practical significance of the sphenoidal air sinus?
Trans-sphenoidal surgery can be formed (through nose) to remove tumours from hypophysis gland
Where is the maxillary air sinus located?
V. large and v. close in proximity to molars and pre-molars
What is the significance of having only 1 opening to the maxillary sinus?
Patients w/ sinusitus can get block
Maxillary sinus often infected and mucous membrane can get congested
Obstruction can cause chronic sinusitis ˙.˙ high location opening maxillary sinus, when head erect, impossible for sinus to drain until they’re full
If positioned on medial side, sinus will only allow upper sinus to drain eg. right sinus drains if lying on left side
How can a tooth ache/abcess affect the maxillary sinus?
Can cause referred pain in maxillary sinus and polyps in sinus can cause tooth ache
How can you treat polyp growth in the maxillary sinus?
Polypectomy - open bone to allow drainage from maxillary sinus and remove polyps
May have chronic fluid build up in area can’t be treated by antibiotics
What is an oroantral fistula?
Pathological abnormal communication between oral cavity and maxillary sinus
Why may an oroantral fistula occur?
May be due to failure of healing a primary OAF, dental infections, osteomyelitis, radiation therapy, trauma
Iatrogenic complications develop when oro-antral communication fails to close spontaneously so remains patent and gets epitheliated
How does the maxillary sinus and teeth change as grow older?
Grow as the skull grows
Teeth whittle away - can cause issues
Where does the procerus muscle attach?
Attaches onto nabella
Where does the nasalis muscle attach?
Runs over the full aspect nasal bone w/ attachment to maxilla around fibrofatty cartilage
What is the function of the levator labii superioris alaeque nasi?
Enables to scrunch nose
What are the adenoids?
Pharyngeal tonsils
Malt tissue (protective)
Mucosal cell associated lymphatic tissue - grow and help to protect kids
Can be removed with tonsils if inflammed
Where is the pharyngeal tonsil located?
On the posterior wall and roof of the nasopharynx
What is the torus tobarius?
Ridge in nasopharynx lies posterior to opening of auditory tube
What is the significance of the tubal tonsil/ opening auditory tube?
Connects middle ear cavity to back nasopharynx
Bacteria can get trapped here
What is the hypophysis?
Pituitary gland
What is the nasal vestibule?
Lined with small, coarse hairs
Area just inside nostril that leads into nasal cavity, supported by cartilage of nose
What is the foramen cecum?
Embryological remnant of back of tongue
Maxillary sinus by middle ear
Where is the opening of the frontonasal duct?
Empties into middle nasal meatus
Drains directly from above
Close to ethmoid air cells -
very thin - if get fractured = problem
Where does the nasopharynx get to?
The entire superior portion
Once get to uvula = oropharynx
What does the external carotid supply?
Gives off maxillary artery
3rd portion terminal branches supplies the nasal cavity
Supplies upper maxilla, lower mandible, deep facial areas and nasal cavity
Supports both hard and soft tissues
What are the other blood vessels that supply the nasal cavity?
Terminal branches of the facial artery - palatine tonsils, soft palate, submandibular gland
Ethmoidal arteries - branches of ophthalmic artery (originates from ICA)
Passes through optic canal
Supply anterior and posterior inside nose, eyeballs, ocular muscles and surrounding structures
What is Little’s area?
Area on nasal septum where branches facial, maxillary and ophthalmic arteries anastomose
Common site nose bleeds
Aka. Kiessellbach’s plexus
Where does the venous drainage go to?
Goes into cavernous sinus
Eventually goes into internal and external jugular veins
Where do the lymphatics drain?
Drain along the same venous aspect
What is the innervation of the nasal region?
Olfaction - olfactory nerve CNI
Goes through cribiform plate
General sensation:
Ant. region - opthalmic nerve V1
Post. region - maxillary V2
Where maxillary artery is
All glands are supplied by PS fibre in greater petrosal nerve @ back - branch of facial nerve VII
Anteriorly = ethmoidal nerve external branch
Greater palatine nerves @ front go through foramena
and have nasopalatine nerves
Describe the course of the greater petrosal nerve
It goes through and hits the pterygopalatine ganglia
Runs alongside where V2 branch exits - through olfactory bulb through cribiform plate
Other nerves also join the ganglia - Post. superior lateral nasal branches from V2
Where do the greater and lesser palatine nerves run along?
Runs along palatine aspect, goes through palatine foramena, have greater foramena at front
Which nerves supply the meatus?
Branches of maxillary nerve
Ant aspect - V1
Post aspect - V2
What is the supply of the concha?
Apart from cribiform plate have sensatory nerves
Branches of V2 - posterior via pterygopalatine ganglion
What do the great and deep petrosal nerves supply?
Help supply the auditory tube
Which nerve is at the back?
Glossopharyngeal nerve CNIX
List the nerve supply of the paranasal sinuses
Frontal sinus - supraorbital V1, anterior. ethmoidal sinuses
Ethmoidal sinus - anterior and posterior ethmiodal branches of nasocilliary nerve
V1 + V2 blood supply same as frontal
Maxillary sinus - infra-orbital and alveolar nerves (V2)
and superior alveolar arteries (maxillary artery)
Sphenoidal sinus - posterior ethmoidal nerve from V1+V2 pterygopalatine ganglion
Blood supply = pharyngeal arteries (maxillary artery)
What type of cartilage is the larynx made up of?
3 paired and 3 unpaired cartilage
List aspects of the cartilaginous skeleton of the larynx
Epiglottis Thyroid Cricoid Aytenoid - attachment point for vocal cords Corniculate and cuneiform - paired Cricoarytenoid joint Crico-thyroid joint
What is significant about the hyoid bone?
Doesn’t articulate with other bones
Instead has lots muscles and structures attach to it
Has anterior and posterior horns
Describe thyroid cartilage
Has horns superiorly and inferiorly
Composed of two halves, which meet in the middle at a peak called the laryngeal prominence, also called the Adam’s apple
Above the thyroid gland
What is the thyroepiglottic ligament?
Connects thyroid to epiglottis