Embryology; Development of Face/Nose/Ear Flashcards
The posterior-most portion of the seconday palate does not ossify, it extends posteriorly to form the _____ _____ and _____
soft palate
uvula
True or False
The cleft lip can only occur unilaterally
False; it can occur unilateral, bilateral, or at the midline
The perilymphatic space has 2 divisions; the _____ ____ and the _____ _____; both are filled with perilymph
scala vestbuli
scala tympani
The 1st and 2nd pharyngeal arches form the _____ _____
auditory vessicles
At the end of month 3, the 1st ____ _____ appears
ossification center (in the skull)
The prominences from due to proliferation of _____ _____, mainly from the 1st pharyngeal arches and from _____ _____ at level of midbrain and rostral hindbrain
neural crest
The external ear developes from _____ ______: mesenchymal proliferations surrounding the 1st pharyngeal groove (as the mandible develops, these shift towards eye level)
auricular hillocks
All of the sinuses except for the _______ develop ______ birth
maxillary
after
The intermaxillary segment consits of the _____ of upper lip (labial component), the _______ part of the maxilla (upper jaw component), and the _______ ______
philtrum
premaxillary
primary palate
The saccular regions consists of the ______ and _____ ______
saccule
cochlear ducts
The nasallacrimal groove is lost when the _____ nasal prominences fuse with the _______ prominences so that the sides of the nose are continuous with the upper cheeks
lateral
maxillary
The _____ ______ growns out as an extension from saccular region and coils to from the membraneous ______
cochlear duct
cochlea
During the fetal period, the cranium expands to accompany growing brain, which causes eyes to shift ______ and _______
anteriorly and medially
The ectoderm of the otic placodes invaginates in each placode, forming an ____ ___, the edges of which pinch off to form an _____ ____ that separates surface ectoderm; it will become the _____ _______ for each ear
otic pit
otic vesicle
membranous labrynith
The 1st pharyngeal pouch expands as the _____ ______ and gives rise to the ________ tube, _____ cavity, _______ antrum, and the ______ of tympanic membrane
tubotympanic recess
Eustachian (pharyngotympaic)
tympanic
mastoid
ectoderm
Both nasal pits deepen and expand _____ into _____ ____, which will form the right and left nasal cavities
dorsally
nasal sacs
At first, a cleft exists vetween the lateral nasal prominences and the maxillary prominences; this is the __________ ________
nasolacrimal groove
The _____ ______ _____ marks where lateral palatine processes fused together
median palatine rahpe
Nasal cavities are separated from oral cavity by ______ _____ membrane, which ruptures at week___; the oral and nasal cavities now in communication through ______ ________
oronsal membrane
6
primordial choanae
Ectoderm proliferates (in the nasolacrimal groove) into underlying mesenchyme and forms a solid rod that separetes the surface and calalizes to become the ______ ______
nasolacrimal duct
In week __, two plates of mesenchyme the ____ ______ processes, extend medially to from the maxillary prominences
lateral palatine
True or False
As the maxillary prominences grow in size and move medially, they compress the medial nasal cavity away from the midline
False; they compress the medial nasal prominences TOWARD midline
The primary palate and anterior portion of the secondary palate will ossift forming the _____ _____
hard palate
During month 3 the facial features become even more ______, the eyes move ______, the ears move _______, the _______ reaching proportional size to the rest of the body
pronounced
medially
superiorly
limbs
A ____ ____ is a posterior palatal defect caused by failure of lateral palatine processes to fuse
cleft palate
The otic vesicle can be divided into two regions; the ______ region (dorsal) and the ________ region (ventral)
utricular
saccular
The ________ prominences (2) extend lateral to stomodeum
maxillary
Cell bodies of CN ____ migrate along coils of cochlear duct and form the ____ ____
VIII
spiral ganglion
The _________ extends from otic vesicle to form the ___________ duct and sac
diverticulum
endolymphatic
The epithelium of nasal placodes sinks down into underlying ________ to form depressions called _____ ______, the also appear to sink in due to the surrounding elevations (medial/lateral nasal prominences)
mesenchyme
nasal pits (the future nostrils)
True or False
There are cleft lips which can extend to the nose, cleft jaws which split the maxilla between the lateral incisor and canine, and clefts between the primary and secondary palatss
True
The 5 facial primordia form during week ___?
4
The inner ear develops as a bilateral thickening in surface ectoderm at the level of the caudal hindbrain called the _____ ______ (2)
otic placodes
True or False
The maxillary prominences fuse before the mandibular prominences
False; the mandibular priminences fuse at the midline before the maxillary
At day 28 the _________ prominences fuse together
mandibular
True or False
Cleft palate can arise due to lateral palatine processes fail to grow, failure of them to fuse, or by micrognathia (insufficient room in oral cavity for tongue to drop, therefore disrutping palate fusion)
True
Palatine processes project___________, then swing upwards to assume the horizontal position, and fuse with each other, the primary palate, and nasal septum
inferomedially
The proportions of the facial skeletal become more normal once the _____ and ______ grow
maxilla and mandible
The cartilage surrounding the cochlear duct ossifies to form the _____ _____ encasing the inner ear structures
bony labyrinth
The remainder of the hard palate and the soft palate + uvula make up the _______ _____
secondary palate
An anterior palatal defect caused by failure of medial nasal promiences to fuse with maxillary prominences on one or both sides; can result is ______ _____
cleft lip/upper jaw
At the end of week 4, two ectodermal thickenings devlop within frontonasal prominence; the _____ _____
nasal placodes
True or False
A cleft palate is more common in males
False; it is more common in women
Cells in the walls of the coiled choclear duct form the _____ _____ of _____
spiral organ of Corti
Nasal ______ develop from lateral walls of the nasal cavity
conchae
With development of secondary palate, we have definite _____ separating nasal cavities from nasopharynx
choanae
Most of the facial structures develop during weeks ____-____
4-8
These develop as bulging prominences around the stomodeum
5 facial primordia
The __________ prominence (1) extends from rostral to stomoedum
frontonasal
During the fetal priod, the ears begin to move _____
superiorly
A thickening of _______ develops in the floor of the lasolacrimal groove
ectoderm
Roof of nasal cavity is invaded by specialied cells that frown out of _______ (________) to form _______ epithelium
forebrain (neuroectoderm)
olfactory
The formation of the palate takes place in weeks ____-____
6-12
During the fetal period, the nose becomes more ______
prominent
The 1st pharyngeal groove forms the _____ _____ _____
external acoutsic meatus
The primary palate froms from a fusion of the _____ _____ prominences an the secondary palate forms from the fusion of the ______ _____ processe
medial nasal
lateral palatine
When the medial nasal prominences fuse (early in week __) they from the ______ ______
6
intermaxillary segment
The 1st pharyngeal arches extend to form the _______ and ________ prominences
maxillary and mandibular
The _______ ______ marks where secondary palate fuses with primary palate; it is used to indicate anterior and posterior palatal defects
incisive canal
The stomodeum is the precursor to the _______
mouth
Surface ectoderm invaginates with 1st pharyngeal groove and meets endoderm extension of 1st pharyngeal pouch to form 1st pharyngeal membrane = ______ _______
tympanic membrane
The _____ ear in the first to develop in week ___
inner
4
_________ surrounding the nasal placodes proliferates, froming elevations
mesenchyme
The __________ prominences (2) extend caudual to stomodeum
mandibular
The rostral hindbrain extends to from the ________ prominence
frontonasal
The primary palate consits of the most ______ portion of the ______ palate
anterior
hard
Vacuoles develop in cartilage surrounding the cochlear duct and unite to from the ______ ______
perilymphatic space
There are _____ medial and _____ lateral nasal promienences
two for each
The utricular region consists of the _____ and _____ _____
utricle
semicircular ducts
True or False
A cleft in the soft palate is more severe than a cleft in the hard and soft palate
False: a cleft in the hard and soft palate is more severe
The superior end of the nasolacrimal duct dilates to form the _______ _____, and the inferior end opens up into _____ _____ of nasal cavity
nasolacrimal sac
inferior meatus