Anatomy Flashcards
what forms the nasal septum?
superior component- perpendicular plate of the ethmoid
posterior/inferior component- vomer
anterior component- septal cartilage
what are the foramen of the nasal cavity?
anterior and posterior ethmoidal foramen
sphenopalatine foramen (sometimes appears as a fissure)
incisive foramen
from what area does epistaxis occur?
keisselbachs plexus
(little’s area)
which arteries are found in little’s area?
anterior ethmoidal
posterior ethmoidal
sphenopalatine artery
greater palatine artery
septal branch of superior labial artery
where does the ophthalamic artery branch from?
internal carotid artery
what type of epithelium is the nasal vestibule?
stratified squamous epithelium (keratinised to non-keratinised)
what type of epithelium is the nasal cavity?
inferior-posterior: olfactory epithelium
superioposterior- respiratory epithelium
what is the olfactory pathway?
- receptor cells in the olfactory epithelium
- pass up through cribiform plate
- synapse with olfactoey bulb (ganglia)
- neurons then pass along olfactory tract
- to temporal lobe and olfactory areas
what are the features of the facial nerve?
parasympathetic secretomotor supply
special sensation (taste)
somatic motor
general sensory
where is the pterygopalatine ganglion located?
the pterygopalatine fossa
what kind of nerve are V1 and V2 of CN7?
general sensory only
what kind of nerve is responsible for dry eyes, mouth and mucosa?
parasympathetic secretomotor supply
what kind of nerve is responsible for a lack of taste on the anterior 2/3 of tongue?
special sensation (taste)
what kind of nerve is responsible for facial paralysis?
somatic motor
what is the function of the external ear (pinna)
collects soundwaves and funnels them into the external acoustic meatus
what nerves innervate the auditorial canal?
CN v3 (mandibular division of the trigeminal nerve) and the auriculotemporal nerve
which nerves innervate the helix?
lesser occipital nerve
greater auricular nerve
which nerve innervates the inferior parts of EAM and tympanic membrane?
vagus nerve
what is the main function of the middle ear?
conduct soundwaves in the ear towards the fluid filled cavities of the inner ear
ossicles increase in size lateral to medial- true or false?
False- decrease in size
what is the function of ossicles?
amplification
what are the features of the tensor tympani muscle?
runs from cartilaginous portion of the eustachian tube to the handle of malleus
dampens sound by reducing vibrations of tympanic membrane
innervated by CN v3
what are the features of the stapedius?
runs of pyramidal eminence to the neck of stapes
dampens sound by reducing vibrations of stapes on oval window
innervated by CN 7
what is pressure in the middle ear usually equal to?
surrounding air pressure
what do palate muscles do?
open eustachian tubes to equalise pressure
what nerve conveys general sensation of the tympanic cavity?
CN9 via the tympanic plexus
what can mastoiditis cause?
osteomylitis
where is the mastoid antrum located?
continuous with the tympanic cavity and lined with mucosa
what are the features of the otic capsule?
located in the temporal bone
bone is denser than the rest of the temporal bone
fully developed at birth
where are hair cells located and what do they do?
located in the cochlear apparatus in the organ of corti
detect auditory stimuli
where does conductive hearing loss happen?
external ear
middle ear
where does sensorineural hearing loss occur?
inner ear
what detects angular movement change?
semi-circular duct
what detects linear movement changes?
utricle (horizontal)
saccule (verticle)
in what planes are the 3 semicircular canals orientated?
anterior- sagittal
posterior- coronal
lateral- axial
what is the role of the chorda tympani?
translates the taste from the anterior 2/3 of the tongue back to the facial nerve
what is the course of the glossopharyngeal nerve?
leaves CNS at the upper medulla oblongata
passes through jugular foramen
enters the parapharyngeal space and lays on the stylopharyngeus muscle
which nerve gives somatic motor supply to the stylopharyngeus?
glosspharyngeal
what is the parasympathetic pathway of the glossopharyngeal nerve?
preganglionic axon-passes through the middle ear and middle cranial fossa to exit the foramen ovale
then goes to the otic ganglion (just inferior to the foramen ovale)
then to the post ganglionic axon- joins auricotemporal nerve (CN V3) which courses close the parotid gland
which nerve supplies the posterior 1/3 of the tongue?
glossopharyngeal
what is the function of the larynx?
respiratory- Facilitate passage of air
between the atmosphere
and lungs
protective- Reduce the potential from
aspiration of items into
the airway
phonation- Generate vibrations in air
to aid communication
what does contraction of the posterior cricoarytenoid cause?
lateral rotation at cricoarytenoid joint
(Widens rima glottidis)
how is the protective function of the larynx achieved?
through glottic closure and cough reflex
the lateral cricoarytenoid muscle firmly closes the rima glottidis
what is needed for phonatory function of the larynx?
inspiration
controlled expiration
phonation
what are the features of controlled expiration?
Contraction inspiratory muscles
Helps build pressure in respiratory tree inferior to
larynx (subglottal pressure).
Pressure required depends on vocal task (whisper,
normal speech, shouting)
what are the features of phonation?
Once subglottal pressure threshold is reached
then air crosses vocal cords causing vibration
Length/tension of vocal cords dictates pitch of
sound produced by vibration of the cords
Degree of opening and the shape of the rima
glottidis also important
which type of muscle are intrinsic laryngeal?
skeletal (voluntary)
what is the impact of vocal cord movements?
Tension (Increase pitch)
Relaxation (Decrease pitch)
Adduction (Quieter)
Abduction (Louder)
which nerve innervates all intrinsic muscles of the larynx?
inferior laryngeal branch of CN X
what muscles relax vocal ligament?
thyroarytenoid muscle
what muscles tense vocal ligaments?
cricothyroid muscles
what are the vocal features of thryoarytenoid muscles?
decreases pitch (lowering voice)
what are the attachments of the thyroarytenoid muscle?
posterior thyroid to anterior arytenoid cartilage
what are the vocal features of the cricothyroid muscles?
increases pitch (raises voice)
what are the attachments for the cricothyroid muscles?
anterolateral cricoid cartilage to the inferior horn of thyroid cartilage
which muscles control changes to the rima glottidis?
laryngeal muscles (relaxed)
posterior crico-arytenoids (contracts-forced respiration)
lateral crico-arytenoids (contract-whispering)
arytenoids contract (assist lateral crico-arytenoids- phonation)
what is the innervation of the larynx?
mucosa above the vocal folds- internal laryngeal nerve
mucosa below the vocal folds- inferior laryngeal nerve
all intrinsic muscles apart from cricothyroid are supplied by inferior laryngeal nerve
what is the cough reflex?
involuntary protective mechanism
sensory stimuli in the supraglottis is conveyed to the brain stem via the vagus nerve
what are the features of glottic closure?
done by the lateral cricoarytenoid and arytenoid
how does a cough happen?
build up of high air pressure due to contraction of the diaphragm muscles
how is the innervation of the pharynx tested?
ask patient to swallow water
watch the larynx move up and down
do they splutter?
how is innervation of the larynx tested?
hoarse voice?
what is dysphonia?
inability to produce an appropriate level of phonation
what are some causes of dysphonia?
neoplastic
neuromuscular
inflammatory
and more
where do supraglottic tumours drain to?
superior deep cervical nodes
where do glottic tumours occur and drain to?
present on the cords
95% stay on the cords
present with voice changes/airway obstruction
where do subglottic tumours drain to?
spread to pratracheal nodes
present with voice/airway obstruction
how do oral sounds occur?
soft palate tenses (CN v3) and elevates (CN X) to close off entrance to nasal pharynx
direct stream of air through oral cavity
sound interupted by tongue (CN XII) and the teeth/lips (CN VII) to produce vowels and and consonants
how do nasal sounds occur?
soft palate tenses (CN v3) and descends (CN X) to close off entrance to oral pharynx
direct stream of air through nasal cavity
produces one of 3 sounds (“ m “ “n” or “ing” ) depending on position of tongue (CN XII), teeth and lips (CN VII)
what are the 3 phases of swallowing?
oral phase (voluntary)
pharyngeal phase (involuntary)
oesophageal phase (involuntary)
what is involved in the oral phase?
masticatory muscles (Cn v3) breakdown food and allow it to mix with saliva
facial muscles (CN VII) creates
- a labial seal (orbicularis otis)
- tightens cheek (buccinator)
intrinsic and extrinsic tongue muscles (CN VII) manipulate bolus and align it between dentition and push it against hard palate
soft palate (CN X) depresses to create oropharyngeal seal and tongue ripples bolus posteriorly
what type of epithelium is the palatal rugae?
keratinised stratified squamous epithelium
what type of nerve is hypoglossal?
somatic motor
what muscles of the tongue does hypoglossal supply?
all muscles of the tongue that end in -glossus
except palatoglossus
what is the route of the hypoglossus nerve?
extends down from the medulla
passes through the hypoglossal canal
descends close to the carotid sheath
and then courses lateral to hyoglossus into the floor of the mouth
what is involved in the pharyngeal phase?
delivery of bolus to oropharynx initiates the involuntary pharyngeal phase
critical phase that lasts <1 second (switch from air channel to food channel)
what is the pharyngeal phase facilitated by?
elevation of soft palate
- seals off nasal pharynx from oropharynx
posterior pressure from tongue
- seals off laryngeal aditus with help from epiglottis
hyolaryngeal elevation
-protects airway
-opens upper oesophageal sphincter
pharyngeal constrictor contraction
how does hyolaryngeal elevation occur?
hyoid bone is dragged superiorly and anteriorly by the suprahyoid and longitudinal pharyngeal muscles.
this, coupled with posterior tongue pressure from the stylohyoid and hyoglossus forces the epiglottis inferior to the tongue and covers the laryngeal aditus
how long does the oesophageal phase last?
8-20 seconds
what are the features of the pharyngeal plexus?
innervates the muscles of the soft palate and pharynx (except tensor veli palatini)
formed by CN IX and CN X
what is the gag reflex?
a protective reflex which prevents unwanted material from entering the GI or resp tracts
what are the features of the sensory component of the gag reflex?
activated when stimuli are presented to the posterior 1/3 of tongue, palatine tonsils or wall of oropharynx
all innervated by CN IX
afferent
what are the features of the motor component of the gag reflex?
close off nasopharynx and contraction of the pharyngeal muscles
these muscles include
- constrictors of pharynx (CN X)
-longitudinal muscles of pharynx (CN IX and X)
-tongue (CN XII) and soft palate (CN X and CN v3)
efferent
what are the features of the motor component of the gag reflex?
close off nasopharynx and contraction of the pharyngeal muscles
these muscles include
- constrictors of pharynx (CN X)
-longitudinal muscles of pharynx (CN IX and X)
-tongue (CN XII) and soft palate (CN X and CN v3)
efferent
which structure provides a pathway for infection to spread to the tympanic cavity
pharyngotympanic tube (eustachian tube)
what is the largest sinus in the face
maxillary sinus
which nerve supplies the internal tympanic membrane?
glossopharyngeal nerve
which nerve passes through the internal acoustic meatus?
facial nerve
which laryngeal muscle is involved in increasing pitch of voice?
cricothyroid muscles
which nerve controls general sensation at the anterior 2/3 of the tongue?
lingual nerve (CN V3) (mandibular division)
what does chorda tympani supply?
parasympathetics to salivary glands and taste to anterior 2/3 of the tongue
which nerve is responsible for referred otalgia from the orogpharynx
glossopharyngeal
which part of the ear does the stapes footplate sit on
oval window
which skull bone is the internal acoustic meatus located in?
temporal bone
which nerve innervates chorda tympani
trigeminal nerve
(mandibular branch)
where does the nasolacriminal duct drain?
inferior meatus
which nerve moves the tongue?
hypoglossal nerve
how many branches in the neck does the internal carotid have?
0
which nerve supplies taste to the anterior 2/3 of the tongue?
facial nerve
name one of the bones that makes up the hard palate?
maxilla
which nerve passes through foramen ovale?
CN v3
which is the largest nasal concha?
inferior
which ossicle is attached to the tympanic membrane?
malleus
which nerve supplies the nose and throat?
glossopharyngeal
which muscle abducts the vocal cords?
posterior cricoarytenoid muscle
