Anatomy Flashcards
What are the functions of the nasal cavity
Patent conduit for air to pass to nasopharynx
Filters particles from air - small hairs
Humidifies air
Warms inspired air
Sense of smell
Which part of the nasal cavity is responsible for smell
Olfactory epithelium
The nose is made entirely of bone - true or false
False
Only the root is bone, the rest is cartilage
Which bones make up the nose
Ethmoid bone Vomer Nasal bone Nasal process of Maxilla Palatine bone Inferior concha
Which two bones form the septum
Perpendicular plate of the ethmoid
Vomer
Describe the structure of the ethmoid bone itself
Perpendicular plate is the mid section - forms septum
Has crista galli on top which separates hemispheres
Either side has the superior and middle concha
Lots of air cells either side
What structures is the ethmoid bone a part of
Septum
Roof
Lateral walls
of nasal cavity
Which class of fracture can disrupt the ethmoid bone
Le Fort II and III
Affects the cribiform plate
What are the potential nasal consequences of Le Fort fractures
Loss of smell - anosmia
Can disrupt the sinuses
This can allow infection to spread
What type of epithelium lines the nose
In the vestibule (outermost) it is stratified squamous
Then becomes respiratory
Superior part has olfactory
Describe the olfactory pathway
Signal picked up by receptor cells in the olfactory epithelium
Passes up through cribiform plate
Synapses with olfactory bulb
Neurons pass along the olfactory tract
Pass to temporal lobe and olfactory areas
What is the innervation of the nasal cavity
Olfactory nerve cells in the olfactory mucosa
V1 for superior part - anterior ethmoid nerve
V2 for posterior part - nasopalatine nerve
What is Kiesselbach’s area
Site of artery anastomoses in the nose
Located anteroinferiorly on the septum
Which arteries supply the nasal cavity
Anterior and posterior ethmoidal arteries - branch of ophthalmic
Sphenopalatine and greater palatine - branch of maxillary
Lateral nasal and septal - facial artery
What is epistaxis
Nose bleed
How many conchae are found in the lateral nasal wall
3
Superior, Middle and Inferior
which recess is found in the lateral nasal wall
Sphenoethmoidal recess
What is the function of the nasal conchae
Create turbulent airflow through the nasal cavity
This increases the chance of humidifying, warming and filtering the air
List the 4 pairs of sinuses associated with the nasal cavity
Frontal sinuses - frontal bone
Ethmoidal air cells
Maxillary sinuses - cheeks
Sphenoid sinuses - back of nose
What lines the paranasal sinuses
Respiratory epithelium
What drains through the sphenoethmoidal recess
The sphenoid sinus
Which sinus drains through the superior meatus
Posterior ethmoidal air cells
Which sinus drains through the middle meatus
Frontal sinus
Maxillary sinus
Anterior ethmoidal air cells
Which sinus drains through the ethmoidal bulla
Middle ethmoidal air cells
Which sinus drains through the inferior meatus
Nasolacrimal duct
What is sinusitis
Inflammation of the mucosa in 1 or more of the paranasal sinuses
Will get excess mucus
May lead to swelling and build up of pressure
The maxilliary sinus is predisposed to infection - true or false
True
Ostium sits superior to it’s cavity
Cilia must work against gravity to clear the sinus
How can tooth problems affect the sinuses
Tooth infection can lead to sinus infections if the roots pierce upwards into maxillary sinus
List the parts of the temporal bone
Squamous part Petrous part Pterion External acoustic meatus Mastoid process Styloid process Zygomatic process
Which nerves are found ‘in’ the temporal bone
Facial (CNVII)
Vestibulocochlear - CNVIII
What does the facial nerve supply
Motor to face
Motor to stapedius
Taste to Ant. 2/3rds of tongue
Secretomotor to salivary glands and lacrimal gland
General sensation to posterior part of external ear - posterior auricular branch
What is the function of the vestibulocochlear nerve
Roles in balance and hearing
Where does the labyrinthine artery come from
Branch of anterior, inferior cerebellar artery
This comes from the circle of Willis
What passes through the internal acoustic meatus
Facial nerve
Vestibulocochlear nerve
Labyrinthine artery
How is the ear divided anatomically
External ear - auricle to tympanic membrane
Middle ear - tympanic membrane to oval window
Inner ear - oval window to internal acoustic meatus
What is the function of the external ear
Collects and conveys sound waves to tympanic membrane
What is the function of the middle ear
Amplifies and conducts sound waves to the internal ear
Includes the eustachian tube
What is the function of the inner ear
Converts special sensory information Into fluid waves, then APs and then conducts APs to brain
Describe the structure of the ear canal
Composed of 1/3 cartilage, 2/3 bones
Lined with skin - squamous epithelium with some hair cells
Produces earwax via ceruminous glands
The external cartilage of the ear it avascular- true or false
True
List the innervation to the auricle
C2,3 spinal nerves innervate most of it via the greater auricular nerve- lobe to helix and some of posterior area
Lesser occipital branch supplies lateral aresa
Mandibular branch of the trigeminal innervates superior part of the external acoustic meatus and most of the ear drum
CNX innervates inferior EAM and tympanic membrane
The facial nerve gives sensation to the concha part of the ear (posterior)
List the lymphatic drainage of the auricle
Lateral part of superior auricle drains to parotid nodes
Medial part of superior half goes to mastoid nodes
The rest (inc. lobe) goes to superficial cervical node
All will eventually end up in the deep cervical nodes
List the parts of the tympanic membrane
Pars flaccida - thin part of membrane at the top
Par tensa - thicker, inferior part
Umbo - handle of malleus
Cone of light - anterior and inferior
List the nerve supply to the tympanic membrane
External surface is CNV3
Internal is CNIX
What parts of the ENT system does the glossopharyngeal nerve supply
Internal surface of tympanic membrane
Middle ear cavity
Eustachian tube
The branch to these structures is called the Jacobson’s nerve
Nasopharynx
Oropharynx
Tonsils
What are the 3 bones of the middle ear
Malleus
Incus
Stapes
Which muscles are found in the middle ear
Stapedius
Tensor tympani
How to the ossicles articulate
Via synovial joints
What is the oval window
Connection between middle and inner ear
Stapes fits into it
Which nerve supplies sensation to the naso/oropharynx
CNIX - glossopharyngeal
Which nerve supplies sensation to the laryngopharynx
Mostly CNX - vagus
What does the eustachian tube connect
Connects anterior wall of the middle ear cavity to nasopharynx
Allows air to get into the middle ear to control pressure
Describe the path of the facial nerve
Leaves brain at pontomedullary junction Passes through the internal acoustic meatus Enters the facial canal Gives off chorda tympani Passes through stylomastoid foramen Supplies face
What does the chorda tympani supply
Taste buds of the anterior 2/3rds of the tongue (may lose taste if damaged)
Parasympathetic supply to the submandibular & sublingual salivary glands (salivation)
What is the function of the stapedius muscle
Reduces stapes movement to protect the internal ear from excessive noise
What happens to facial fat as we age
Atrophy
Which nerve supplies the inner ear
CNVIII - vestibulocochlear
In 2 parts
Cochlear nerve - hearing
Vestibular nerve - balance
What is contained in the bony labyrinth
Filled with perilymph fluid
Semi-circular canals are suspended in the fluid
What fills the semi-circular canals
Endolymph
Which AP’s travel via the vestibular nerve
Those originating in the semi-circular ducts
Which AP’s travel via the cochlear nerve
Those originating in to cochlear duct
How is movement detected in the inner ear
Hair cells are stimulated by movement of endolymph
Semi-circular canals detect angular movement
Utricle detects horizontal
Saccule detects vertical
How is sound transmitted in the ear
Sound waves make the tympanic membrane vibrate
Transmit through ossicles
Stapes vibrates the oval window
This creates pressure waves in perilymph of the inner ear
Hair cells in cochlea move and stimulate AP’s
Pressure waves become vibration again and are dampened at round window
What detects auditory stimuli
Receptor cells in the organ of Corti
Found in the cochlear duct
Describe the path of the vestibulocochlear nerve
Leaves brain at pontomedullary junction
Passes through internal acoustic meatus
Contacts the cochlear and semi-circular duct
At what level is the hyoid bone found
Level of C3
Where does the submandibular gland secrete saliva
Sublingual caruncle - bump under tongue
Where does the sublingual gland secrete saliva
Beneath the sublingual folds (under the tongue)
Which muscles make up the floor of the mouth
Mylohyoid
Geniohyoid - connects chin and hyoid
What innervates the mylohyoid
CNV3
What innervates the geniohyoid
C1 - via hypoglossal nerve
Where does the parotid gland secrete salvia
By the upper 2nd molar
Which nerves innervate the salivary glands
Parotid - glossopharyngeal (CNIX)
Piggybacks on CNV3
Other 2 is the facial nerve
Which nerves supply the tongue
Posterior 1/3 - taste and sense by CNIX
Anterior 2/3 - sensory from V3 and taste from CNVII
List the muscles of the tongue and their innervation
Palatoglossus - vagus
Styloglossus, Genioglossus and Hyoglossus - hypoglossal nerve
Describe the path of the hypoglossal nerve
Leaves from medulla
Passes through hypoglossal canal
Descends lateral to carotid sheath
Passes towards tongue at level of hyoid
How can you test CNXII - hypoglossal
Ask patient to stick their tongue straight out
In unilateral CN XII damage the tongue tip will POINT TOWARDS
the side of the injured nerve
List the blood supply to the tongue
Lingual artery - branch of external carotid
Which bones form the hard palate
Palatine process of the maxilla
Palatine bone
Pterygoid hamulus from sphenoid
List the muscles of the soft palate
Tensor veli palatini Palatophrygeus Levator veli palantini Musculus uvulae Palatoglossus
What is the innervation of the soft palate muscle
All CNX apart from tensor veli palatini which is CNV3
What are the functions of the soft palate
Stops food entering the nose during swallowing
Directs air into the nose or the mouth during speech, sneezing, coughing & vomiting
Helps to close off the entrance into the oropharynx in the gag reflex
How can you test CNX
Ask patient to say ahhh
If there is a unilateral nerve damage the uvula will be pulled away from the non-functioning side
Get them to swallow a small amount of water - does the larynx move, do they splutter?
Listen to speech - is it hoarse
Can they produce a powerful cough
Describe the muscles of the pharynx
3 constrictor muscles in the outer layer
3 paired vertical muscle in the inner layer
All skeletal and all innervated by CNX
What is the gateway to the mouth
The gap between the superior and middle circular muscle of the pharynx
CNIX, lingual artery and the stylopharyngeus muscle pass through here
Which nerve supplies the Stylopharyngeus
glossopharyngeal nerve
Name the 3 longitudinal muscles of the pharynx and their innervation
Stylopharyngeus - CNIX
Palatopharygeus - CNX
Salpingopharygeus - CNX
What are the components of Waldeyer’s tonsillar ring
Adenoid
Tubal tonsil
Palatine tonsil
Lingual tonsil - back of tongue
How do lymph nodes appear in infection
Swollen
Painful
Soft and smooth
Not fixed
How do lymph nodes appear in cancer
Swollen
Not painful
Hard and irregular
Fixed
What are the functions of the larynx
Contains the voice box
It acts as a sphincter in the respiratory tract - regulates airflow and protects from aspiration
Warming and humidifying air and also for filtration of infection
Needs to stay open - patent URT
Where is the larynx found
Between the pharynx and trachea
Between C4 and C6
Between the two carotid sheaths
Enclosed in the pretracheal fascia
What structure does the Adam’s apple indicate
The top of the thyroid cartilage
How does the larynx help protect you from aspirating
It raised up when we swallow to reduce chance of material getting in
Epiglottis also moves to close the inlet
What forms the ‘skeleton of the larynx
Hyaline cartilage that is suspended from the hyoid bone: Epiglottis Thyroid cartilage Cricoid cartilage Arytenoid cartillages
Name the joint between the thyroid and cricoid cartilages
Cricothyroid joint
What happens when you put pressure on the cricoid cartilage
It compresses the oesophagus
Larynx stays open
Can be used in ventilation
What are the true vocal cords
Vocal process of arytenoid cartilage to thyroid cartilage
Covered in connective tissue
Movement of them allows us to make sound
What are the false vocal cords
Sit either side of the true ones
They connect the arytenoid cartilage to epiglottis
What is the vallecula
The space between the epiglottis and tongue
Laryngoscope is placed here
Describe how different movements of the vocal cords affect speech
Tension - increased pitch
Relaxation - decreased pitch
Adduction - quiet
Abduction - loud
Which intrinsic muscles act as tensors of the larynx
Cricothyroid muscles
Which intrinsic muscles act as relaxers of the larynx
Thyroarytenoid muscles
Which intrinsic muscles act as adductors of the larynx
Lateral crico-arytenoid muscles
Arytenoid muscles
Which intrinsic muscles act as abductors of the larynx
Posterior Crico-arytenoid muscles
When vocalising the vocal cords are close together - true or false
True
For voice production you need the vocal cords to come together and vibrate
Also needs the lungs to create normal air pressure
How do glottic tumours present
On the cords - 95% will stay here
Present with voice changes and airway obstruction
Where do supra-glottic tumours spread to
Superior, deep cervical nodes
Where do sub glottic tumours spread to
Paratracheal nodes
less room to spread before causing an issue
How can you speak after the larynx is removed
Tracheo-oesophageal puncture - button thing
Oesophageal speech - learn to force air up through oesophagus to create speech, fit a prosthetic valve
Electrolarynx - machine used to generate sound
What nerve supplies the intrinsic laryngeal muscles
Inferior laryngeal nerve
Branch of recurrent laryngeal
Describe what the branches of the laryngeal nerve supply
Superior branch splits into internal and external
Internal - sensory to muscos above cords
External - motor to criciothyroid muscle
Inferior branch = intrinsic muscles
Which abnormalities can be seen in the external auditory meatus
Genetic problems: - underdevelopment or atresia of the canal
- underdevelopment of the ear itself (ear will look unusual)
Severity of these can vary from mild to severe
Leads to conductive hearing loss
Describe the structure of the tympanic membrane
External layer is squamous epithelium, middle fibrous layer and then inner resp epithelium
Which branch of the vagus nerve supplies the external ear canal
Arnold’s nerve
What is the nerve supply to the face
Trigeminal - ophthalmic, maxillary and mandibular (general sensation to the face)
Rest of the head/neck is supplied by branches of the cervical plexus - greater occipital, lesser occipital, greater auricular, transverse cutaneous (anterior neck), supraclavicular nerve (laternal neck)
Posterior neck = c3 c4
What causes referred ear pain
The pathways of the nerves supplying the ear converge or overlap in places which is why pain from elsewhere can refer to the ear - e.g. larynx, pharynx
What are the 3 anatomical areas of the larynx
Above the true cords - supraglottic
Around the cords is the glottis
Below this is the subglottic
What separates the larynx and the oesophagus
Epiglottis
Where are tracheostomies usually placed
- Usually placed between 2nd and 3rd tracheal rings
However, need to place below the level of obstruction in order to oxygenate properly so may move slightly
What forms the anterior triangle of the neck
Bordered by the mandible superiorly, SCM laterally, clavicle inferiorly and the vertical midline of the neck marks the anterior border
How is the anterior triangle of the neck divided
Into 4 smaller triangles
Submandibular
Submental
Muscular triangle - contains strap muscles
Carotid/jugular triangle - common carotids and bifurcation, hypoglossal and vagus nerves
What are the branches of the common carotid artery
Internal and external
What forms the posterior triangle of the neck
Bordered by the SCM anteriorly, lateral part of the clavicle inferiorly and the trapezius posteriorly
How is the posterior triangle of the neck divided
Subdivided into two more triangles - subclavian and occipital
List the 7 levels of head/neck lymph nodes
1 - submental and submandibular - drains oral cavity and floor of mouth
2,3,4 - anterior cervical chain
2 - angle of mandible to hyoid - drain from tonsils, oropharynx
3 - between hyoid and cricoid cartilage - primary drain sites include oropharynx and larynx
4 - below cricoid and above sternal notch - drains larynx
5 - posterior triangle - associated with nasopharynx
7 - supraclavicular nodes, typically a upper GI tract - Virchow’s node
What does the internal carotid artery supply
It courses up to the cranial cavity and supplies the brain (joins the circle of WIllis)
What does the external carotid artery supply
External supplies the face, scalp and neck
Branches include superior and inferior thyroid artery, ascending pharyngeal, lingual artery (oral and tongue), facial artery, occipital artery (scalp and back of head), post auricular, maxillary and temporal
