The Ear Flashcards
T/F:
The ear is located in the temporal bone
False
Most of it is EXCEPT the cartilagenous auditory tube which can be found in the groove along the petrosphenoidal suture
What is the eardrum also known as? what is its function?
Also known as the tympanic membrane
Role is for transmission and amplification of sound
What is the middle ear also known as? What is its function?
Tympanic cavity
Role is for transmission and amplification of sound
What consists of the inner ear and what is the role of this structure overall?
Cochlea, semicircular canals and vestibule
Purpose is to turn vibrations into neuronal impulses and transmit to the brain
T/F:
The auditory tube connects the inner ear with the nasopharynx
False
It connects the middle ear with the nasopharynx
T/F:
The lateral 1/3 of the external ear is bony and the medial 2/3 is cartilagenous
False
lateral 1/3= cartilagenous
Medial 2/3= bony
Which glands in the external ear produce wax?
Ceruminous glands
Where can you find hair in the external ear?
Lateral 1/3 cartilagenous part
T/F:
External ear is medial and slanted anteriorly
True
T/F:
Entire external acoustic meatus is lined with thick skin
False
thin skin
T/F:
Lateral surface of the tympanic membrane is concave and covered in skin
True
T/F:
The medial surface of the tympanic membrane is convex and covered in skin
False
covered in mucosa
What is the UMBO? Where is it?
Bottom of the handle of malleus attached to the convex medial surface of the tympanic membrane
It is the point of maximum medial convexity
T/F:
Semicircular canals are more anterior than the cochlea
False
They are more posterior
T/F;
The malleus and incus are found on the lateral side of the tympanic membrane/ear drum
False
Medial side
Which nerve passes across the tympanic membrane in between the malleus and incus?
Chorda tympani
T/F:
Pars flaccida is above the malleus and pars tensa is below
True
What type of joint is the joint between the incus and stapes?
Synovial
What substance is within the tympanic cavity?
Air
Which two structures does the mastoid additus connect?
Middle ear/tympanic cavity and the mastoid air cells
What makes up the lateral wall of the tympanic cavity?
Tympanic membrane
List the two main features of the anterior wall of the tympanic cavity
Auditory tube opening
Carotid canal
Which nerve runs above the auditory tube?
Tensor tympani
it then bends to run along the medial wall
Where does the epithymapnic recess lead to and which wall of the tympanic cavity can it be found in?
Found in the posterior wall
Leads to the aditus which leads to the mastoid antrum which leads to the mastoid air cells
Which nerve branches on the posterior wall of the tympanic cavity?
Facial nerve branches into chorda tympani
T/F:
Facial nerve runs medially to aditus on the posterior wall of the tympanic cavity
False
Runs inferiorly
Which tendon emerges in the posterior wall of the tympanic cavity?
Pyramid tendon of stapedius
Which bone separates the middle ear from the middle cranial fossa and where can it be found in the tympanic cavity?
Tegmun tympani
Makes up the roof of the tympanic cavity
T/F:
Tegmun tympani is posterolateral to the arcuate eminence
False
anterolateral
What makes up the floor of the tympanic cavity?
Thin bone covering the jugular fossa/foramen
The medial wall of the tympanic cavity is mostly _____
Bony
Which structure is inferolateral to the oval window on the medial wall of the tympanic cavity?
Round window
T/F:
The malleus closes the oval window
False
Base of the stapes
What closes the round window?
Membrane
Which two prominotaries can be found in the medial wall of the tympanic cavity?
Inferiomedial= over the cochlea
More superiorly= over the lateral semicircular canal
What is the tympanic plexus and which wall of the tympanic cavity can it be found on?
On the medial wall of the tympanic cavity
Tympanic branch of glossopharyngeal and sympathetic from internal carotid plexus
What type of bone are the ossicles and what are they covered in?
Dense compact bone
covered in mucosa
T/F:
The head of the malleus is in the epitympanic recess
True
Which part of the malleus is attached to the tympanic membrane and which nerve crosses it?
Handle
Chorda tympani crosses it
T/F;
Body of the incus articulates with the handle of the malleus
False
articulates with the head of the malleus
T/F:
The short limb of the incus articulates with the head of the stapes
False
the long limb does
What attaches to the short crus of the incus?
Ligamentous attachment
Which part of the stapes attaches to the oval window?
The stapes
What is the function of the two muscles in the tympanic cavity?
Contract in response to high intensity sounds to protect the inner ear
T/F:
The muscular part of stapedius lies in a canal in the medial wall of the tympanic cavity
False
Posterior wall
Stapedius attaches to which part of the stapes?
Tendon emerges from the pyramid and attaches to the neck of the stapes
T/F:
Cranial nerve 5/3 supplies stapedius
False
facial nerve does
T/F:
Tensor tympani muscle runs within a bony canal posterolateral to the cartilagenous auditory tube
False
Runs ABOVE the cartilagenous auditory tube
T/F:
Tendon of tensory tympani makes a 90 degree turn as it emerges from its bony canal and runs across the middle ear to the handle of the malleus. It is supplied by cranial nerve 5/3 (medial pterygoid branch)
True
Which artery supplies the majority of the ossicles?
Anterior tympanic artery
branch of the maxillary artery
Name two other blood supplies of the ossciles other than the anterior tympanic artery
Deep auricular
Posterior auricular plexus
Where does the auditory tube extend from?
Middle ear to the lateral wall of the nasopharynx
T/F:
The auditory tube is bone anteromedially and cartilagenous posterolaterally
False
Bone posterolaterally
Cartilagenous anteromedially
Which groove does the auditory tube sit in?
Petrosphenoidal suture
T/F:
The auditory tube is normally open and closes during swallowing, coughing and positive pressure
FALSE
normally closed and opens during swallowing, coughing and positive pressure
List the four muscles attached to the auditory tube
Levator palate (medial) Tensor palate (lateral) Salpingopharyngeus (superior border at the pharyngeal end) Tensor tympani (superior)
Does the bony or membranous labrynth contain perilymph?
Bony
high sodium and low potassium contents, like CSF
Which liquid is contained within the membranous labrynth?
Endolymph
T/F:
The cochlea sits medially to the vestibule of the inner ear
False
Anterior
What structure is posterior to the cochlea?
Vestibule of the inner ear
T/F:
The apex of the cochlea is directed laterally
True
T/F:
The first turn of the cochlea produces the promontory in the posterior wall of the tympanic cavity
False
Medial wall
What is contained within the modioulus of the cochlea?
Spiral ganglion
Transmit fibres to the sensory cells in the cochleal duct
T/F:
The three semicircular canals are superoposterior to the vestibule
True
T/F:
The posterior canal is horizontal to the edge of the middle cranial fossa
False
It is parallel
(the lateral canal is horizontal)
T/F:
The anterior canal is at a 45 degree angle to the edge of the middle cranial fossa and produces the arcuate eminence
False
90 degree angle
Which wall of the tympanic cavity does the lateral canal produce a bump?
Medial wall
The cochleal duct is a _______ duct
Blindly ending
T/F:
The scala vestibule leads to the round window
False
it comes from the vestibule
(The scala tympani leads to the round window)
Which nerve is found between the facial and vestibular nerve when they emerge from the inferior border of the pons?
Nervus intermedius
T/F:
The facial nerve separates from the vestibular nerve in the medial part of the internal acoustic meatus and passes into a separate facial canal
True
Where do the cochlea and vestibular nerve separate?
In the lateral end of the internal acoustic meatus
After it separates from the cochlea nerve, where does the vestibular nerve travel to?
Vestibular sensory ganglion in the lateral part of the inner ear and then forms five branches
T/F:
The cochlea nerve goes to the spiral ganglion in the modiolis
True