Pharyngeal Apparatus

Question 1

Embryonic origin of skeleton of face

Answer 1

Neural crest in mesodermal mesenchyme

Question 2

Arterial component of the 3rd arch (and thus 3rd aortic arch) will become

Answer 2

part of the internal carotid artery

Question 3

Muscular derivatives of arches 4 through 6

Answer 3

cricothyroid, levator palatini, constrictors of pharynx, intrinsics of larynx

Question 4

Nerves for arches 4 through 6

Answer 4

Vagus nerve: 4- superior laryngeal, 6- recurrent laryngeal

Question 5

Derivitive of 1st Pouch AND Cleft

Answer 5

Auditory (eustacian) tube including external auditory meatus and middle ear cavity, tympanic membrane which has contributions from ALL THREE germ layers.

Question 6

Origin of tonsilar fossa and palatine tonsils

Answer 6

From 2nd pouch. Fossa is from pouch itself. Tonsils have contribution from endodermal epithelium and lymph tissue

Question 7

Dorsal aspect of 3rd pouch

Answer 7

Inferior parathyroid, hitches ride on thyMUS

Question 8

ventral aspect of 3rd pouch

Answer 8

thymus

Question 9

dorsal aspect of 4th pouch

Answer 9

superior parathyroid, hitches ride on thyROID

Question 10

ventral aspect of 4th pouch

Answer 10

ultimobranchial bodies

Question 11

fate of 1st pharyngeal cleft

Answer 11

external auditory meatus

Question 12

fate of clefts 2-4

Answer 12

Covered by 2nd arch mesenchyme

Question 13

Branchial Sinus

Answer 13

blind ended cavity with drainage to external environment

Question 14

Branchial Fistula

Answer 14

A continuous connection between what were originally a pouch and cleft

Question 15

Pierre Robin Sequence

Answer 15

Hypoplasia of mandible aka micrognathia. Cleft palate due to posterior displacement of tongue aka Glossoptosis

Question 16

DiGeorge Syndrome

Answer 16

Thymic and parathyroid insufficiency can lead to immune defficiency. Micrognathia, lowset prominent ears, cardiovascular defects.

Question 17

Embryonic structure of each arch

Answer 17

Core with mesenchyme from paraxial and lateral plate mesoderm. Outside surface with epithelial ectoderm. Inside surface with endodermal epithelium.

Question 18

Arterial component from 1st arch (thus 1st aortic arch) becomes

Answer 18

Maxillary artery

Question 19

Arterial component from 2nd arch (thus 2nd aortic arch) becomes

Answer 19

Stapedial artery

Question 20

Arterial component from 4th arch (thus 4th aortic arch) becomes

Answer 20

Subclavian artery

Question 21

Nerve for 1st arch

Answer 21

Trigeminal, maxillary and mandibular

Question 22

Nerve for 2nd arch

Answer 22

Facial

Question 23

Nerve for 3rd arch

Answer 23

Glossopharyngeal

Question 24

Muscular derivatives of arch 1

Answer 24

muscles of mastication, anterior belly of digastric

Question 25

muscular derivatives of arch 2

Answer 25

muscles of facial expression, posterior belly of digastric

Question 26

Cartilage derivatives of arch 1

Answer 26

Maxillary, Mandibular from Meckel’s cartilage which includes Incus and Malleus

Question 27

Cartilage derivatives of arch 2

Answer 27

Lesser horn, upper body of hyoid, Stapes

Question 28

Cartilage derivatives of arch 3

Answer 28

lower part of hyoid bone and greater horn