Embryology Review Flashcards
Which of the pharyngeal arch regresses?
5th Arch
What tissue are clefts related to?
Ectoderm
What tissue are pouches related to?
Endoderm
What tissue are arches related to?
Mesoderm
What are the muscles and nerves of the 1st pharyngeal arch?
CN V
Muscles of Mastication
What are the muscles and nerves of the 2nd pharyngeal arch?
CN VII
Muscles of Facial Expression
What are the muscles and nerves of the 3rd pharyngeal arch?
CN IX
Stylopharyngeus
What are the muscles and nerves of the 4th pharyngeal arch?
CN X - External Laryngeal
Cricothyroid
What are the muscles and nerves of the 6th pharyngeal arch?
CN X - Recurrent Laryngeal
Intrinsic Muscles of Larynx
What structures come from the 1st pouch?
Tympanic Membrane
“Ears”
What structures come from the 2nd pouch?
Palatine Tonsils
“Tonsils”
What structures come from the 3rd pouch?
Inferior Parathyroid
“Bottom To”
What structures come from the 4th pouch?
Superior Parathyroid
“Top”
Where are branchial cysts found?
At the anterior border of the sternocleidomastoid
Where are thyroglossal cysts found?
It draws down the thyroid gland and its at the midline of the neck
What aortic arches are regressed?
1st, 2nd and 5th
What does the 3rd aortic arch become?
Common Carotid
What does the right 4th arch become?
Right Subclavian
What does the left 4th arch become?
Arch of the Aorta
What does the right 6th arch become?
Right Pulmonary
What does the left 6th arch become?
Left Pulmonary and Ductus Arteriosus
What is the fate of the ventral mesentery?
It becomes the lesser omentum and the falciform ligament
What is the fate of the dorsal mesentery?
It becomes the greater omentum
Where does the stomach rotate and why?
Space cannot accommodate the rapidly growing organs and as a result, they must rotate 90 degrees to the right
