Kuehn - pharyngeal arch formation

Question 1

where do the pharyngeal arches begin

Answer 1

with the gut tube - as small columns on either side of embryonic pharynx

Question 2

what 4 regions does the gut tube expand and differentiate into

Answer 2

pharynx, esophagus, stomach, and mid-gut

Question 3

as the 1st arch bends around the oral plate, what are the 2 parts it forms

Answer 3

maxillary and mandibular divisions

Question 4

how many pharyngeal arches are there

Answer 4

1, 2, 3, 4, and 6 (5 only exists in embryo growth and no structures arise from it)

Question 5

what are the aortic arch derivatives and what arises from them

Answer 5

AA 3 - carotid, AA4- left arch aorta and right subclavian, and AA6 - pulmonary AA

Question 6

what cranial nerves arise from PA1 maxillary division and PA2 mandibular division

Answer 6

maxillary of trigeminal and mandibular of trigemnial

Question 7

what cranial nerve arises from PA2

Answer 7

facial nerve

Question 8

what cranial nerve arises from PA3

Answer 8

glossopharyngeal nerve

Question 9

what cranial nerve arises from PA4/6

Answer 9

vagus nerve

Question 10

what muscle arises from PA1

Answer 10

muscles of mastication

Question 11

what muscle arises from PA2

Answer 11

muscles of facial expression

Question 12

what muscle arises from PA3

Answer 12

stylopharyngeus muscle

Question 13

what muscle arises from PA4

Answer 13

cricothyroid and muscles of pharynx

Question 14

what muscle arises from PA6

Answer 14

intrinsic muscles of larynx

Question 15

what bone arises from PA3

Answer 15

hyoid bone

Question 16

what bone/cartilage arise from PA4/6

Answer 16

cartilage of larynx (thyroid and cricoid cartilage)

Question 17

what are the proximal parts of meckels cartilage

Answer 17

malleus and incus bones by endochondrial ossification

Question 18

what is the middle part of meckels cartilage

Answer 18

sphenomandibular ligament

Question 19

what are the distal parts of meckels cartilage

Answer 19

induces intra-membranous ossification around cartilage at mandible then disappears

Question 20

what comes from Reicherts cartilage

Answer 20

stapes, styloid process, stylohyoid ligament and lesser horn of hyoid bone

Question 21

what arises from the pharyngeal pouch 1

Answer 21

middle ear and auditory tube

Question 22

what arises from the pharyngeal pouch 2

Answer 22

palatine tonsil

Question 23

what arises from the pharyngeal pouch 3

Answer 23

parathyroid and thymus

Question 24

what arises from the pharyngeal pouch 4/5

Answer 24

parathyroid, C-cells of thyroid

Question 25

what arises from the pharyngeal groove 1

Answer 25

external auditory meatus

Question 26

what do the pharyngeal grooves that fuse behind the 2nd arch form

Answer 26

cervical sinus

Question 27

what happens if the cervical sinus forms but doesn’t involute

Answer 27

branchial cleft cyst forms - benign but can become infected