Orofacial Exam 2
No ____ and no ___opening in the beginning
oral; anal
stomodeum
The external depression which finally breaks through to establish the oral opening into the foregut
the topographical center of the developing facial structures
oral plate
two layered membrane where the stomodeal depression is deepened, and the ectodermal (outside)
floor comes to lie against the entodermal (inside) lining of the foregut
head of a young embryo is pressed against its __________
thorax
frontal prominence
a rounded elevation in the midline, above the stomodeum
nasal (olfactory) placodes
local thickenings of the ectoderm on either side of the frontal prominence, near the lateral margins of
the overhanging frontal prominence
destined to form the lining of the nasal pits
horse shoe shaped
pg. 1
, Orofacial Exam 2
During the _____ week all the major structures involved in the formation of the face and jaws become
clearly distinguishable
fifth
The upper jaw is of ______ origin (maxillary process)
composite (multiple pieces)
the nasal pits
bordered by the nasal placodes
Later become nares
They appear to have sunk below the general surface
nasomedial processes
The medial limbs of the nasal placode around the nasal pits
nasolateral processes
lateral limbs of the nasal placode around the nasal pits
pg. 2
, Orofacial Exam 2
_______ become center part of your upper lip, important feature in the coming together of the upper
jaw
Nasomedial processes
_________ becomes alar cartilage at the side of your nose, looks like gull wing (ala means wing)
Nasolateral processes
The nasomedial processes play an important part in the formation of the medial portion of the
________, ______, and ________.
upper jaw, lip, and palate (Philtrum, Premaxilla, Columella)
maxillary processes
Grow toward the midline from the upper lateral angles of the oral cavity
destined to form the lateral parts of the upper jaw
Eventually comes together with nasomedial process
nasal fin
Juncture between nasomedial process and maxillary process
intermaxillary segment
all of the upper oral arch, which is of nasomedial origin
pg. 3
, Orofacial Exam 2
three components of the intermaxillary segment:
1) the labial component- the medial portion of the upper lip or prolabium (philtrum)
2) the gnathogingival (jaw-gum) component within which will develop the portion of the upper jaw
carrying the incisor teeth (alveolar process of the premaxilla)
3) the hard palate component or primary medial palatal triangle (process) (the rest of the premaxilla).
prolabium
philtrum
gnathogingival (jaw-gum) component
alveolar process of the premaxilla
medial palatal triangle (process)
the rest of the premaxilla
medial palatal primordium is continuous with the most anterior portion of the ________
nasal septum
nostrils (external nares) and posterior nares (nasal choanae)
the downward extension of the original pits themselves which, during the sixth week, break through
into the upper part of the oral cavity
the external openings of the nasal pits
the formation of the palate elongates the _______ backward
nasal chambers
_________ as it comes from above, comes from frontal prominence downward and fuses with
intermaxillary segment (premaxilla) and also the rest of the hard palate
pg. 4
No ____ and no ___opening in the beginning
oral; anal
stomodeum
The external depression which finally breaks through to establish the oral opening into the foregut
the topographical center of the developing facial structures
oral plate
two layered membrane where the stomodeal depression is deepened, and the ectodermal (outside)
floor comes to lie against the entodermal (inside) lining of the foregut
head of a young embryo is pressed against its __________
thorax
frontal prominence
a rounded elevation in the midline, above the stomodeum
nasal (olfactory) placodes
local thickenings of the ectoderm on either side of the frontal prominence, near the lateral margins of
the overhanging frontal prominence
destined to form the lining of the nasal pits
horse shoe shaped
pg. 1
, Orofacial Exam 2
During the _____ week all the major structures involved in the formation of the face and jaws become
clearly distinguishable
fifth
The upper jaw is of ______ origin (maxillary process)
composite (multiple pieces)
the nasal pits
bordered by the nasal placodes
Later become nares
They appear to have sunk below the general surface
nasomedial processes
The medial limbs of the nasal placode around the nasal pits
nasolateral processes
lateral limbs of the nasal placode around the nasal pits
pg. 2
, Orofacial Exam 2
_______ become center part of your upper lip, important feature in the coming together of the upper
jaw
Nasomedial processes
_________ becomes alar cartilage at the side of your nose, looks like gull wing (ala means wing)
Nasolateral processes
The nasomedial processes play an important part in the formation of the medial portion of the
________, ______, and ________.
upper jaw, lip, and palate (Philtrum, Premaxilla, Columella)
maxillary processes
Grow toward the midline from the upper lateral angles of the oral cavity
destined to form the lateral parts of the upper jaw
Eventually comes together with nasomedial process
nasal fin
Juncture between nasomedial process and maxillary process
intermaxillary segment
all of the upper oral arch, which is of nasomedial origin
pg. 3
, Orofacial Exam 2
three components of the intermaxillary segment:
1) the labial component- the medial portion of the upper lip or prolabium (philtrum)
2) the gnathogingival (jaw-gum) component within which will develop the portion of the upper jaw
carrying the incisor teeth (alveolar process of the premaxilla)
3) the hard palate component or primary medial palatal triangle (process) (the rest of the premaxilla).
prolabium
philtrum
gnathogingival (jaw-gum) component
alveolar process of the premaxilla
medial palatal triangle (process)
the rest of the premaxilla
medial palatal primordium is continuous with the most anterior portion of the ________
nasal septum
nostrils (external nares) and posterior nares (nasal choanae)
the downward extension of the original pits themselves which, during the sixth week, break through
into the upper part of the oral cavity
the external openings of the nasal pits
the formation of the palate elongates the _______ backward
nasal chambers
_________ as it comes from above, comes from frontal prominence downward and fuses with
intermaxillary segment (premaxilla) and also the rest of the hard palate
pg. 4
