Cleavage and blastocyst formation — Flashcards

Flashcard 1: What is the embryonic origin of the parathyroid gland and parafollicular C cells? _____

Answer: Parathyroids: Endoderm (3rd & 4th pharyngeal pouches) Parafollicular C cells: Neural crest

Flashcard 2: What day of fetal development is characterized by amnion formation?_____

Answer: Day 8 (thus twins that split after day 8 are monoamniotic)

Flashcard 3: On which days following fertilization is the morula formed?_____

Answer: 3-4

Flashcard 4: What is the embryonic origin of the ovaries/testis? _____

Answer: Mesoderm

Flashcard 5: Abnormal prenatal development of the acetabulum is caused by excessive _____

Answer: uterine packing (uterine constraint)

Flashcard 6: mastoid air cells

Answer: 1st pouch

Flashcard 7: Endoderm lined structures of the ear (1st pharyngeal pouch)

Answer: 1st pouch

Flashcard 8: Embryological origin of the thymus

Answer: 3rd pharyngeal pouch (ventral wing)

Extra: The 3rd pharyngeal pouch gives rise to the Thymus (ventral wing) and the Inferior Parathyroid glands (dorsal wing). Compare with the 4th pharyngeal pouch, which gives rise to the Superior Parathyroid glands.

Flashcard 9: inferior parathyroids

Answer: 3rd pouch

Flashcard 10: superior parathyroids

Answer: 4th pouch