EX1; Formation of Face and Oral Cavity Flashcards
What is the order in which the face, oral cavity/palate, and tongue develop
face
tongue
oral cavity
This is an organization level involved in the growth and development of an organ and an organism
formation
This is an increase in weight and spatial dimensions (shape) that an organ or organism undergoes
growth
This is the growth of an organ or organism through various formative stages on its way to maturity
development
During which embryonic weeks does the face develop
three to five
What is the crown-rump measurement during the 3rd week
3mm
The stomodeum appears during which embryonic week
three
What does the stomedeum become between the 6th and 8th week
nasal and oral cavity
What are the boundaries of the stomodeum
frontal prominence (superior) cardiac plate (inferior) buccopharyngeal membrane (posterior)
What type of epithelium lines the stomodeum
ectoderm
What type of epithelium makes up the buccopharyngeal membrane
2 layers; endoderm and ectoderm
During the fourth week what appears
4 pairs branchial (pharyngeal, visceral) arches
branchial clefts or grooves
When do the branchial arches disappear
in the 4th week (of when they appear also)
*What does branchial Arch 1 become
right and left maxillary facial processes
right and left mandibular facial processes
What does the groove (cleft 1) between the mandibular process and arch II become
external auditory meatus
What is the place where the maxillary and mandibular processes meet at either side of the stomodeum
commissure laborium oris (corner of lips)
This replaces the cardiac plate as the lower boundary of the stomodeum during the 4th week
2 mandibular facial processes
This becomes the posteriolateral boundary of the stomodeum during the 4th week
2 maxillary facial processes
These appear within the frontal prominence during the 4th week
nasal pits
*After the appearance of the nasal pits, the frontal prominence becomes what
three processes;
median nasal facial process
right lateral nasal facial process
left lateral nasal facial process
The nasal pits deepen and become what
nasal ducts that open into the stomodeum, then to nostrils that open to nasal cavities during the formation of oral and nasal cavities
What does the median nasal process become
midline of nose
philtrum of upper lip
What do the lateral nasal processes become
lateral sides and ala (wings) of nose
infraorbital part of face
What does the maxillary process become
upper part of cheeks
lateral parts of upper lip
What does the mandibular process become
lower part of cheeks
lower lip
chin
What do the maxillary processes merge with
median nasal process
Failure of the maxillary processes to merge by the end of the 5th week will result in what
clefting (unilateral or bilateral) of the upper lip
What does branchial arch II become
operculum (cover)
What is the operculum
an embryonic fold of tissue that covers arch III and IV and clefts II, III, and IV
What does the operculum become
sides of neck below the external auditory meatus
This takes place between the facial processes during facial formation
merging
When would clefting in the mandible appear
by the 5th week, if merging does not occur
What makes up the upper lip
right maxillary facial process
medial nasal facial process
left maxillary facial process
What makes up the lower lip
right and left mandibular process
What happens to the buccopharyngeal membrane
it ruptures allowing opening to the foregut that becomes the oral and nasal pharynx
site of the anterior pillar of fauces
What appears during the 4th becoming the tongue
four lingual swellings along the ventral inside surface of mandibular processes of branchial arch I, II, and III; the merge to form the tongue
These lingual swellings become the anterior 2/3 of the tongue
tuberculum impar (middle) 2 lateral lingual
This becomes the posterior 1/3 or root of the tongue
copula
After what week will the stomodeum portioned into the oral and nasal cavities
6th week
This arises from the inner surface of median nasal facial process during the 5th week
primary palate
This arises from the primary palate during the 5th week
nasal septum
This arises from the inner surface of maxillary facial process during the 5th week
palatine folds
What type of epithelium covers the palatine folds
lining epithelium connects to an underlying mesenchymal tissue
The palatine folds move from a vertical position to where
a horizontal position above the tongue
The edges of the palatine folds with the primary palate form what kind of shape
“Y”
When does the palate epithelium begin to fuse
begins in the 6th week
How does palate fusion progress
posterior;
the palate folds fuse with each other, then the nasal septum
Where does meschenchyme remain after palatal merging
in the confines walled off by epithelium of palatine folds and nasal septum
it intermingles within these structures
Upon the formation of the secondary palate (an the epithelium gone and mesenchyme union complete) what officially forms
the oral and nasal cavities
When does epithelial fusion and mesenchymal union occur
between 6th and 8th weeks
