Embryology Student Quiz

Which of the following embryonic structures are not involved in the formation of the face?

• Fifth pharyngeal arch

• Frontonasal prominence

• Mandibular prominence

• Maxillary prominence

• Nasal prominence

Answer explanation

The face is developed from the frontonasal prominence with the medial and lateral nasal prominences on its lateral margins, the maxillary and mandibular prominences. All these are derived from the pharyngeal arches and neural crest cells.

The 5th pharyngeal arch does not form any structures.

Identify the structure marked by an arrow in the following diagram of a 5 weeks embryo.

• Frontonasal prominence

• lateral nasal prominence

• Mandibular prominence

• Maxillary prominence

• Medial nasal prominence

What embryonic structure gives rise to the primary palate?

• Frontonasal prominence

• Fused mandibular prominences

• Fused maxillary prominences

• Fused medial nasal prominences

• C and D

Which week of gestation does the formation of the upper lip begin?

• 2nd

• 4th

• 6th

• 8th

• 10th

Fusion of which structures form the secondary palate?

• Both palatine shelves

• Maxillary processes on the two sides

• Palatine shelves with each other and nasal septum

• Palatine shelves with each other and with primary palate and nasal septum

• Palatine shelves with primary palate

What gestation age does the formation of the secondary palate begin?

• 3rd week

• 4th week

• 5th week

• 6th week

• 7th week

What structures form the philtrum?

• Fusion of the frontonasal with maxillary prominences

• Fusion of the lateral nasal and maxillary prominence

• Fusion of the maxillary prominences

• Fusion of the maxillary with the mandibular prominences

• Fusion of the medial nasal and maxillary prominence

What structure forms the sides of the nose?

• Frontonasal prominence

• Lateral nasal prominence

• Mandibular prominence

• Maxillary prominence

• Medial nasal prominence

What approximate gestation age is lip formation completed?

• 6th week

• 7th week

• 8th week

• 9th week

• 10th week

What approximate gestation age is palate formation completed?

• 8th week

• 9th week

• 10th week

• 11th week

• 12th week