Anatomy Flashcards
what is the thinnest part of the skull
the pterion
what are the two parts of the temporal bone
petrous part
squamous part
what is contained in the anterior cranial fossa
frontal, ethmoid and spehnoid
what is contained in the middle cranial fossa
sphenoid and temporal
what is contained in the posterior cranial fossa
temporal and occipital
what is the only cranial nerve to run through the anterior fossa
CNI
what nerves could be damaged in pathology of the internal acoustic meatus
CN VII and VIII
what are the 3 parts of the ear and what are there boundaries
external ear
- auricle to tympanic membrane
- via external acoustic meatus
middle ear
- tympanic membrane to oval window
- also eustachian tube
internal ear
- oval window to internal acoustic meatus
what are the functions of the 3 parts of the ear
external
- collect and conveys sound waves to tympanic membrane
middle
- amplifies and conducts sound waves to the internal ear
internal
- converts special sensory information; into fluid waves, then APs, conducts APs to brain.
why is anaesthetic contained adrenaline not used on external ear
avascular
nutrients from skin
what is the external acoustic meatus/ear canal lined with
skin
- ceruminous glands that produce earwax
what are the lymph nodes surrounding the ear
parotid (pre-auricular)
mastoid (post-auricular)
how is the auricle pulled in otoscopic examination
posteroinferiorly in children
posterosuperiorly in adults
what is the nerve supply of the tympanic membrane
external surface - CN V3
internal surface - CN IX
what does CNIX, the glossopharyngeal nerve provide sensory innervation to
middle ear cavity eustachian tube nasopharynx oropharynx tonsils
what does the eustachian tube connect
middle ear cavity to nasopharynx
laryngopharynx nerve supply
CN X
what are the 3 bones of the middle ear cavity called the auditory ossicles
Malleus
Incus
Stapes
what does the base of the stapes fit into
the oval window i.e. internal ear
what foramen in the base of the skull does CN VII run through
internal acoustic meatus
stylomastoid foramen
what is the course of the facial nerve through the petrous temporal bone
internal acoustic meatus >> facial canal >> stylomastoid foramen
what is chorda tympani
- branch of CN VII
- supply to taste buds of anterior 2/3rds of tongue
- parasymp supply to submandibular and sublingual salivary glands
what is the function of the stapedius
reduces stapes movement to protect internal ear from excessive noise
what does chorda tympani connect with
lingual nerve branch of CN V3
what are the muscles of facial expression
frontalis
orbicularis oculi
elevators of lips
orbicularis oris
how can we test muscles of facial expression and motor function of CN VII
frown
close eyes tightly
smile
puff out cheeks
what are the two parts of CN VIII, the vestibulocohlear nerve
the cochlear nerve (hearing)
the vestibular nerve (balance)
what is the apex of the spiral of the cochlea called
cupula
what are the 3 semi-circular canals called
anterior
lateral
posterior
what is contained in the cochlear duct and the semi-circular canals
cochlear duct - cochlear nerve
semi-circular canals - vestibular nerve
what tuning fork is used to test hearing
512 Hz tuning fork
how is sound transmitted
1 - Sound waves make tympanic membrane vibrate
2 -Vibrations transmitted through ossicles
3 -Base of stapes vibrates in oval window
4 - Vibration of stapes creates pressure waves in perilymph
5 - Hair cells in the cochlea are moved, neurotransmitter is released, Aps stimulated and conveyed to brain by cochlear nerve
6 - Pressure waves descend and become vibrations again
7 - Pressure waves are dampened at the round window
what cannot be used near nasal cartilage
adrenaline-containing local anaesthetics
what part of the ethmoid bone contributes to the roof
cribriform plate and crista galli
what part of the ethmoid bone contributes to the septum
perpendicular plate of ethmoid
rest is made up by the VOMER
what type of fracture can disrupt the cribriform plate and why is this an issue
Le Fort II and III
- danger of infection spreading to the anterior cranial fossa
what is the olfactory bulb
ganglion of CN I
cell bodies of 2nd neurones
where do the receptor cells of CN I pass through
cribriform plate of ethmoid bone
what is the nerve supply of the nasal cavity
Ophthalmic (CN V1)
anterosuperiorly
Maxillary (CN V2)
posteroinferiorly
what is the blood supply of the nasal cavity
External
- facial
- maxillary
Internal
- ophthalmic
what is Kiesselbach’s Area and why is it clinically important
anastomosis of all the arterial blood supply of the nasal cavity
common site for nosebleeds/epistaxis
what are the conchae of the nasal cavities
superior (of ethmoid)
middle (of ethmoid)
inferior
what are meatuses
spaces under each concha
what is the only meatus not under a concha
sphenoethmoidal
what is the nerve supply of the inferior conchae
CN V1
what are the cavities mainly lined by
respiratory epithelium
- pseudostratified columnar with cilia and goblet (mucous-secreting) cells
what do ‘holes’ in the meatus allow
drainage of mucous from the paranasal sinuses
what are the paranasal sinuses
frontal sinuses
ethmoidal (air) cells
maxillary sinuses
sphenoid sinus
what are sinuses lined by
mucous-secreting respiratory mucosa
what are the functions of sinuses
mucous drains into nasal cavities via ostia in the lateral walls of the nasal cavities
where does the frontal sinuses drain into and what also does
middle meatus
maxillary sinus
where do ethmoidal cells drain into
superior and middle meatus
what drains into the sphenoethmoidal recess
sphenoidal sinus
what drains into the inferior meatus
lacrimal gland via the nasolacrimal duct
what provides the painful sensation in sinusitis and where may the pain be referred
CN V1 and V2
Teeth
why is the maxillary sinuses predisposed to inflammation
maxillary sinus ostia being located superiorly
mucous has to drain against gravity
where in the mouth is the opening for the submandibular salivary glands
under the tongue
where does the parotid duct sit
crosses masseter
pierces medially through buccinator
where does the parotid gland come out in the mouth
upper back molars
what is the muscle of the floor of the mouth
mylohyoid
what supplies the sublingual and submandibular gland
CN VII
what is the nerve supply of the anterior 2/3rds of the tongue
general sensory = CN V3
special sensory = CN VII
what is the nerve supply of the posterior 1/3rd of the tongue
general and sensory supply = CN IX
what is the origin of the thyroid gland
foramen caecum
what are the 4 extrinsic muscles of the tongue
palatoglossus
styloglossus
hyoglossus
genioglossus
what does CN XII sit in in the occipital bone
hypoglossal canal
how can CN XII be tested
ask patient to stick out tongue
what are the muscles of the soft palate and what is their function
levator veli palatini - lifts the soft palate towards the base of the skull
tensor veli palatini - tenses the soft palate
palatoglossus - depresses the palate towards the tongue or vice versa
palatopharyngeus - a longitudinal muscle of the pharynx - attaches between the palate and the larynx
musculus uvulae
what is the nerve supply of the muscles of the soft palate
all CN X apart from tensor veil palatini - CN V3
how can CN X and CN V3 be tested
ask the patient to say ‘Aaahh’
what innervates the pharynx
CN X
what protects the pharynx
Waldeyer’s (defensive) ring of lymphoid tissue
what is enclosed in pre tracheal fascia
the strap muscles thyroid gland trachea & larynx oesophagus & pharynx recurrent laryngeal nerves
where is the larynx
between C4 and C6
what level is the hyoid bone
C3
when can vertebra begin to be palpated
C7
what what level does the larynx become the trachea
C6
what is the name of the membrane that connects the hyoid to the thyroid cartilage
thyrohyoid membrane
what is the name of the membrane that connects the thyroid cartilage to the cricoid cartilage
cricothyroid membrane
what is the only cartilage to make a complete ring around the larynx
cricoid cartilage
what is the name of the back of the cricoid cartilage
lamina
where do vocal cords attach to
thyroid cartilage
vocal process of arytenoid cartilages
what is the space between vocal cords called
rima glottidis
what is the mucosa of the larynx
mainly respiratory epithelium:
EXCEPT for the VOCAL CORDS stratified squamous epithelium
what are the false and true vocal cords
F - superior of vocal cords
- vestibular folds
T - inferior of vocal cords
- vocal folds
nerve supply of larynx
CN X
Superior to vocal fold = superior laryngeal branches of CN X
Vocal fold and inferior = recurrent laryngeal branches of CN X
what are the role of cricothyroid muscles
tense the vocal cords
role of thyro-arytenoid muscles
relax vocal cords
pull the arytenoid cartilages towards the thyroid cartilage
role of lateral circa-arythenoid muscles
adduct the vocal cords
rotate the arytenoid cartilages so that the vocal processes of the cartilages come together in the midline
role of the arytenoid muscles
adduct the vocal cords
role of posterior circa-arythenoid muscles
abduct the vocal cords
widens the rima glottidis
how can the vagus nerve be tested
ask patient to swallow small sip of water
listen to patient speak
ask patient to cough
