Brachial Cleft derivatives

Question 1

Brachial clefts are derived from what layer?

Answer 1

Ectoderm

Question 2

1st brachial cleft derivative

Answer 2

external auditory meatus

Question 3

2nd through 4th cleft

Answer 3

temporary cervical sinuses

obliterated by proliferation of 2nd arch mesenchyme

Question 4

Branchial cleft cyst

and what differentiates it from a thyroglossal duct cyst

Answer 4

Persistent cervical sinus —> branchial cleft cyst within lateral neck.

Key features differentiating it from a thyroglossal duct cyst :

1. lateral neck
2. does not move when you ask the patient to swallow