Basic Embryology Flashcards
Buccopharyngeal (oropharyngeal) membrane
A membrane in an early embryo separating the head end of the gut from the stomodeum
Stomodeum
Primitive mouth The anterior or oral portion of the alimentary canal of an embryo
Frontonasal prominence
Embryonic facial swelling of tissues that cover the surface of the forebrain
Maxillary prominence
The dorsal prominence formed by bifurcation of the mandibular (first pharyngeal) arch in the embryo which joins with the medial nasal prominence in the formation of portions of the upper lip, palatal shelves & upper jaw
Mandibular prominence
The ventral prominence formed by bifurcation of the mandibular (first pharyngeal) arch in the embryo, which unites ventrally with its fellow to form the lower jaw
Nasal placodes
Two thickenings that appear on the frontonasal process. They are precursors to the lateral and medial prominences and eventually the nose
Nasal pits
A pair of depressions formed in the developing face giving rise to the nostrils
Medial nasal prominence
An embryological structure that forms the nasal bridge
Lateral nasal prominence
An embryological structure that gives rise to the ala of the nose
Intermaxillary (globular) segment
The lower extension of the merged medial processes which will become the philtrum of the upper lip
Philtrum
A long dimple or indentation that courses from the columella down to the upper lip and is bordered by the philtral ridges on each side
Alveolar ridge
The portion of the maxilla and mandible that forms the base and the bony support for the teeth; also called the alveolus or simply the gum ridge
Palatal shelves (palatine processes)
Outgrowths of the maxillary process that grow into the oronasal cavity, eventually fusing with the primary palate, each other and the nasal septum to form the embryo’s hard palate
When does a child’s cleft lip happen?
4th-8th week of pregnancy
When does a child’s cleft palate happen?
6th-12 week of pregnancy
If the maxillary prominence does not fuse with the lateral nasal prominence what do you get?
Oblique facial cleft
What do you get if the medial nasal processes do not fuse?
Median cleft
What do you get if the intermaxillary globular segment and the maxillary prominence do not fuse?
Cleft lip
What do you get if the palatal shelves don’t fuse?
Cleft Palate
Which five primordia form the origin of the face and mouth in the 4th week?
frontonasal prominence, two maxillary prominences and the two mandibular prominences
What do you get if the mandible does not grow forward?
Pierre Robin Sequence
