Term
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Definition
• Ectoderm is the outermost layer and it gives rise to:
• the entire nervous system (PNS, CNS)
• all hair, nails and skin (epidermis)
• sensory epithelium of the eye, ear and nose
• the pharynx
• the dental enamel |
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Term
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Definition
• Mesoderm is the middle layer and it gives rise to:
• muscle
• connective tissue [primordial embryonic connective tissue] is also
called mesenchyme
• bone and cartilage
• blood vessels
Note: CL+CP results from a disturbance to mesoderm |
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Term
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Definition
• Endoderm is the innermost layer and it gives rise to:
• the linings of the digestive and respiratory tracts |
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Term
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Definition
The term
primordial means the original tissue from which something is formed,
derived.
The anterior neuropore, which is the anterior opening
of the developing neural tube. This neural tube is the primordium for
the central canal of the spinal cord. |
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Term
Branchial Apparatus:
Buccopharyngeal Membrane
(aka Orophyaryngeal membrane) |
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Definition
the oropharyngeal membrane separates the
stomodeum (the primitive mouth opening) from the primitive
pharynx; this membrane ruptures at about 4 weeks gestation,
allowing communication between the primitive gut and the
amniotic cavity |
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Term
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Definition
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Term
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Definition
The frontonasal process differentiates to form the nasolateral and
nasomedial processes. |
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Term
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Definition
The nasal placode is a thickening of the primordial ectoderm, around which the
lateral nasal and medial nasal processes develop.
[ |
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Term
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Definition
| The otic pit will migrate medially and become the external auditory meatus |
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Term
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Definition
The medial nasal (aka nasomedial) processes fuse in midline
and form the primary palate; the primary palate is also called
the intermaxillary segment, the premaxilla, or the pre-palate; it
gives rise to:
*the philtrum and mid-portion of the upper lip
*the four incisor teeth and
*associated maxillary alveolus |
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Term
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Definition
the maxillary processes form the bulk of the [lateral parts of the] upper
lip;
the upper lip is formed by the merging of the maxillary processes with
the nasomedial processes; |
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Term
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Definition
The mandibular processes differentiate to form the mandible, the anterior 2/3 of the tongue** [aka the oral tongue] and the lower lip
** the posterior part of the tongue comes from the 2nd through 4th branchial arches
structures derived from the mandibular process are innervated
by the mandibular division of CN V, the trigeminal nerve |
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Term
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Definition
| The nasal pit will migrate medially and become the nostril. The nasal pit is part of the frontonasal process |
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Term
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Definition
| The naso-optic furrow is where the maxillary and lateral nasal processes meet, and therefore the site of oblique clefting. |
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Term
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Definition
Four branchial arches can be seen on the surface of the head and neck area
in the 4 week-old embryo;they are separated from each other by branchial grooves
• branchial arches are numbered in a cephalad to caudal direction as
arches 1 through 6; the branchial arches support the lateral walls of the anterior foregut, primitive pharynx; the pharyngeal pouches evaginate from the primitive pharynx;Note: Each branchial arch differentiates and gives rise to muscles, cartilages,
bones, and blood vessels; certain cranial nerves [CNs] (V, VII, IX, X)
grow from the brain into specific branchial arches. In fact, CNs V, VII, IX and X are associated with arches 1, 2, 3, and 4, respectively. (see pg. 30 of lecture 5 for detailed photo and explanation of arches. |
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Term
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Definition
If we draw an imaginary wedge from the incisor teeth back to the incisive foramen, that segment of prolabium, incisor teeth, alveolus and palate is the primary palate.the medial nasal (aka nasomedial) processes fuse in midline and form the primary palate; the primary palate is also called the intermaxillary segment, the premaxilla, or the pre-palate. for the primary palate, the direction of closure is downward and
forward with the lip closing last; therefore, the mildest form of
primary palate clefting is a lip notch, often considered a microform of
clefting |
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Term
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Definition
secondary palate closure starts between the 7th and 8th weeks and is completed by the 12th week of gestation; it includes:
• the hard palate posterior to the incisive foramen
• the soft palate and
• the uvula
The secondary palate develops from the two (2) lateral palatine processes,
which are shelf-like outgrowths of the maxillary processes. |
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Term
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Definition
| See pg. 16-19 of module 5. Too much info for this card! |
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Term
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Definition
Lateral clefts [aka transverse clefts] occur because of lack of fusion
between maxillary and mandibular processes; they are often seen as a
component of a syndrome, especially the spectrum of “hemifacial
microsomia.” Clinically, the mouth appears large due to the
lateral/labial corner extension which can be unilateral or bilateral; and
the lateral facial cleft is, therefore, often labeled as macrostomia [note
the relationship between stomodeum and macrostomia] |
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Term
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Definition
| See other set of note cards |
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