Unit 3: Mandible, TMJs, and Sinuses Anatomy (RAD PRO 3)
when does the mandible ossify
1st year of life
the posterior ethmoid air cells range from ______ to ______ and drain into the ______ _______ _______
2-6 superior nasal meatus
the anterior and middle ethmoid air cells range from _____ to _____ and opens into the _______ ______ _______
2-8 middle nasal meatus
at what age are the frontal and sphenoid sinuses distinguishable from the ethmoids
6-7 years old
what is a sound conducting canal
EAM
at the center of the posterior apsect of the petrous portion is the
IAM
what transmits vestibulocochlear and facial nerves
IAM
where do the sphenoid sinuses lie
In the body of the sphenoid bone directly below the sella turcica
concave area at top of ramus between coronoid and condylar processes
Mandibular notch
functions of paranasal sinuses
Serve as resonating chamber for the voice Decrease weight of skull Aid in warming and moisturizing inhaled air Act as shock absorbers in trauma Possibly control the immune system
superior attachment of the auricle
TEA
the top of the petrous ridge lies approximately at the level of the
TEA
the superior border of the body of the mandible consists of a spongy bone called ______ ____________, supports the roof of the teeth
alveolar portion
what are the air cells in the ethmoid sinus
anterior, middle, posterior
What are the semicircular canals?
anterior, posterior, and lateral
what is a rounded eminence located on the inferior border of the zygomatic process- it forms the anterior boundary of the mandibular fossa
articular tubercle
what delicate bones are articulated to permit vibratory motion they bridge the middle ear cavity for the transmission of sound vibrations from the tympanic membrane to the internal ear
auditory ossicles
what is a passage by which air pressure in the middle ear is equalized with the pressure in the outside air passages
auditory tube
what is the oval shaped, fibrocartilaginous, sound collecting organ situated on the side of the head
auricle
parts of the external ear
auricle and EAM
where is the temporal bone situated
base of the cranium (between the greater wings of the sphenoid and the occipital bone)
what is the curved horizontal portion on the mandible
body
the internal ear is composed of an irregular shaped bony chamber called
bony labyrinth
when opens into the foramen lacerum
carotid canal
the outer 1/3 of the canal wall is
cartilaginous
what is used for hearing
cochlea
the maxillary sinus is occasionally divided into 2 sinuses by what
complete septum
the auricle has a deep central depression, which is the lower part and leads into the EAM
concha
posterior process on top of ramus; articulates with mandibular fossa of temporal bone to form temporomandibular joint (TMJ)
condylar process
anterior process on top of ramus
coronoid process
what is the organ of hearing and balance
ear
what sinuses are located within lateral masses of labyrinths
ethmoid sinuses
which sinuses develop during puberty and are not completely developed until 17-18
ethmoid sinuses
t/f: frontal sinuses are always symmetric
false
t/f: the mandible is completely formed at birth
false
near the petrous apex, is a ragged foramen called
foramen lacerum
what sinuses are the 2nd largest and are paired and are normally located between the tables of the vertical plate of the frontal bone
frontal sinuses
the body and the rami unite where
gonion (angle of mandible)
Where is the TMJ situated?
immediately in front of the EAM
wha tis the anvil
incus
what does the carotid canal contain
internal carotid artery
what deviates from the midline and makes the frontal sinuses rarely symmetric
intersinus septum
the temporal bones form a ________ (large/small) part of the middle fossa
large
is the mastoid process larger in males or females
males
what is the hammer
malleus
what are the auditory ossicles
malleus, stapes, and incus
what is the largest and densest bone of the face
mandible
what receives condyle of mandible to form temporomandibular joint (TMJ)
mandibular fossa
the first mastoid air cells to develop is situated at the upper anterior part of the process and is termed
mastoid antrum
what is the large air cavity situated in the temporal bone above the mastoid air cells and immediately behind the posterior wall of the middle ear
mastoid antrum
what does the middle ear communicate with
mastoid antrum and audittory eustachian tube
what is a conical process projecting from mastoid portion
mastoid process
what sinuses a re usually sufficiently well developed and aerated at birth to be shown on a radiograph
maxillary sinuses
which sinus is the largest and most symmetric (they're paired)
maxillary sinuses
which way does the EAM project
medially anteriorly slightly superiorly
the internal ear is housed within the bony chamber and is an intercommunicating system of ducts and sacs known as
membranous labyrinth
small openings on each side below the second premolar; transmit nerves and blood vessels
mental foramen
At the site of ossification is a slight ridge that ends below in a triangular prominence
mental protuberance
The rami project superiorly at an _______ angle to the body of the mandible, and their broad surface forms an angle of approximately...
obtuse, 110-120 degrees
the inner 2/3 of the canal wall is
osseous
the air-filled cavities located in the frontal, ethmoid, and sphenoid bones of the cranium, as well as the maxillae of the face
paranasal sinuses
the maxillary sinus is often divided into sub-compartments by what
partial septa
what forms the inferior posterior part of the temporal bone
petromastoid portion
what contains the organs of hearing and balance
petrous portion
what is the thickest and densest portion of cranium
petrous portion
what projects medially and anteriorly between greater wing of sphenoid and occipital bone... conical or pyramidal in shape
petrous portion
where are the essential parts of the ear housed in
petrous portion of temporal bone
another name for petrous portion
petrous pyramid
what is the upper border of the petrous portion called
petrous ridge
the TMJ slants how
posteriorly 15 degrees inferiorly and medially 15 degrees
what are the 2 vertical portions of the mandible called
rami
the maxillary sinus flood presents several elevations that corresponds to what
roots of subjacent teeth
the temporal bones form a _________ (small/large) part of the posterior fossa
small
what sinuses are normally paired and occupy the body of the sphenoid bone
sphenoid sinuses
what is the thin upper portion of the temporal bone that forms the side wall of the cranium
squamous portion
what does the temporal bone consist of
squamous portion tympanic portion styloid process zygomatic process petromastoid portion (mastoid and petrous portions)
what is the stirrup
stapes
what is a slender, pointed bone projecting inferiorly, anteriorly, and slightly medially from inferior surface of tympanic portion
styloid process
what is the most central and anterior part of the mandible this is where the right and left halves of the mandible have fused
symphysis
auricle has a prominent cartilaginous lip which projects posteriorly over the entrance of the meatus
tragus
what is the function of tympanic membrane
transmission of sound vibrations
t/f: often only 1 sphenoid sinus is present and they are usually asymmetric
true
t/f: the coronoid process is higher that the mandibular condyle
true
t/f: the petromastoid portion usually contains air cells
true
t/f: the sinuses begin to develop early in fetal life, at first appearing as small sacculations of the mucosa of the nasal meatus and recesses
true
t/f: the tympanic cavity communicates with the nasopharynx through the auditory tube
true
the mastoid antrum is large, and communicates with what
tympanic cavity
what is a narrow irregularly shaped chamber that lies just posterior and medial to the mandibular fossa
tympanic cavity
the EAM ends at the __________ __________ of the middle ear
tympanic membrane
what is a thin concavoconvex, membranous disk wit an elliptic shape
tympanic membrane
what does the middle ear consist of
tympanic membrane (ear drum) tympanic cavity auditory ossicles
what is located below squama and in front of petromastoid portion -Forms anterior wall, inferior wall, and part of posterior walls of the EAM
tympanic portion
what are involved with equilibrium
vestibule and semicircular canals
What does the bony labyrinth consist of?
vestibule, semicircular canals, cochlea
the squamous portion contains a prominent arched process which projects anteriorly to articulate with the zygomatic bone of the face and completes the zygomatic arch
zygomatic process
