Lecture 9 - Anatomy + Ear Conditions Flashcards
What are the 3 parts of the ear?
External ear
Middle ear
Inner ear
What are some signs and symptoms of ear diseases in general?
Hearing loss
Otalgia
Otorrhoea
Tinnitus
Vertigo
Facial nerve lesions/palsy
What is otalgia?
Ear pain
What is otorrhoea?
Ear discharge
What is tinnitus?
When sound is perceived but is not actually coming from an external source
Like ringing, humming and whistling…
What situation does facial nerve lesion/palsy occur as a result of ear disease and why?
Disease of the middle ear
Since the facial nerve (VII) runs through the canal of the Petrous bone
What makes up the external ear?
Pinna
External auditory meatus
External auditory canal
Lateral surface of tympanic membrane
What is the pinna/auricle?
The outside cartilaginous bit of the ear which most people refer to as the ear
What type of cells line the external auditory canal?
Keratinised squamous epithelium
What is the tympanic membrane?
What everyone refers to as the ear drum
What type of cavity is the middle ear?
Air filled cavity
What is found in the air filled cavity of the middle ear?
Ossicles
What structures does the middle ear connect to?
Nasopharynx via Eustachian tube/pharyngotympanic tube (PT)
Mastoid process
Sigmoid dural venous sinus
What fills the ducts/tubes of the inner ear?
Fluid
What are the structures of the inner ear?
Vestibulocochlear nerve (VIII)
Semicircular canals
Vestibule = utricle + saccule
Cochlea
What are the ossicles in the ear from attached to the tympanic membrane to deep?
Malleus
Incus
Stapes
Go to the last slide and label the ear:
1 = Pinna
2 = External auditory canal/meatus
3 = Tympanic membrane
4 = Malleus
5 = incus
6 = stapes
7 = Eustachian tube/pharyngotympanic tube
8 = cochlea
9 = semicircular Canals
10 = cochlear nerve
11 = vestibular nerve
12 = external ear
13 = middle ear
14 = internal ear
What cells line the inner ear?
Sterocilia
What is the important bone relevant to the ear?
Temporal bone (Petrous part in particular)
What are the 2 membranous sacs making up the vestibule portion of the inner ear?
Utricle
Saccule
Which of the 2 membranous sacs of the inner ear (vestibule) receive the 3 semicircular canals?
Utricle
What does the saccule connect to?
Cochlea
What are the nerves supplying the external ear with general sensation?
Cervical nerves C2 and C3
Trigeminal nerve
Vagus
CN VII
What nerve supplies the middle ear cavity and medial surface of tympanic membrane with sensation?
Glossopharyngeal (IX)
What are some causes of refered pain to the ear (non ontological causes of otalgia)?
TMJ dysfunction
Oropharyngeal disease like pharyngitis
Laryngeal and pharyngeal cancers
Why can TMJ dysfunction lead to otalgia?
TMJ supplied by the Mandibular division of the Trigeminal nerve (Vc)
The auriculotemporal nerve supplying the ear is a branch of the mandibular division of the Trigeminal nerve (Vc)