Embryology

Question 1

five facial swellings

Answer 1

1) frontonasal process
2/3) paired maxillary processes
4/5) paired mandibular processes

Question 2

medial nasal processes develop into

Answer 2

intermaxillary prominence

Question 3

cleft lip results from ________

Answer 3

cleft lip results from FAILURE OF INTERMAXILLARY PROMINENCE (fusion of medial nasal proceses) TO FUSE WITH MAXILLARY SWELLING

Question 4

primary palate formed by _______

Answer 4

primary palate formed by INTERMAXILLARY SEGMENT OF NASAL PROCESS

Question 5

secondary palate formed by ___________

Answer 5

secondary palate formed by:

PALATINE SHELVES from maxillae grow inward to fuse in midline

Question 6

flat bones of the skull form from

Answer 6

condensation of mesenchymal tissue (INTRAMEMBRANOUS OSSIFICATION) which originally derives from the neural crest

Question 7

each arch contains

Answer 7

• cartilagenous component
• muscular component
• an aortic arch
• a nerve

Question 8

arch 1 innervation

Answer 8

CN V

Question 9

arch 2 innervation

Answer 9

CN VII

Question 10

arch 3 innervation

Answer 10

CN IX

Question 11

arch 4 innervation

Answer 11

CN X

Question 12

arch 6 innervation

Answer 12

CN X

Question 13

arch 1 : artery, skeletal, muscles, CN

Answer 13

• Maxillary artery
• incus, malleus, maxilla, zygomatic, squamous temporal, mandible
• m. of mastication, accessory m of mastication
• CN V (maxillary and mandibular div)

Question 14

arch 2: artery, skeletal, muscles, CN

Answer 14

• stapedial artery, corticotympanic a
• stapes, styloid process, stylohyoid ligament, upper part of hyoid bone
• muscles of facial expression, posterior digastric, tyolohyoid, stapedius
• CN VII

Question 15

arch 3: artery, skeletal, muscles, CN

Answer 15

• common carotid a
• lower part of hyoid
• stylopharyngeus
• CN IX

Question 16

arch 4: artery, skeletal, muscles, CN

Answer 16

• arch of aorta, R subclavian a
• laryngeal cartilages
• constrictors of pharynx, cricothyroid, levator veli palatini
• CN X (superior laryngeal br)

Question 17

first cleft

Answer 17

external acoustic meatus

Question 18

cervical cysts/sinuses can arise from ________

Answer 18

cervical cysts/sinuses can arise from incomplete obliteration of remaining clefts

Question 19

first pouch

Answer 19

middle ear cavity

Question 20

second pouch

Answer 20

palatine tonsillar bed

Question 21

third pouch

Answer 21

inferior parathyroid gland and thymus

Question 22

fourth pouch

Answer 22

superior parathyroids

parafollicular cells of thyroid

Question 23

branchial cleft cyst: failure of obliteration of _________

Answer 23

branchial cleft cyst: failure of obliteration of SECOND branchial cleft in emryonic development

Question 24

inferior parathyroid gland is dragged down with _________ from _________ pouch

Answer 24

inferior parathyroid gland is dragged down with THYMUS from THIRD pouch

Question 25

derivatives of neural crest

Answer 25

• components of eye
• dermal bones of skull
• pharyngeal arch cartilages
• dermis/hypodermis of face and neck
• odontoblasts
• some cranial nerve ganglia
• adrenal medulla
• melanocytes
• dorsal root and chain ganglia

Question 26

sensory to mucosa of anterior 2/3 tongue

Answer 26

arch 1

-lingual n (CN V3)

Question 27

taste buds in anterior 2/3 of tongue

Answer 27

arch 2

-chorda tympani (CN VII)

Question 28

taste/general sensation in posterior 1/3 of tongue

Answer 28

arch 3

-glossopharyngeal n (CN IX)

Question 29

taste/sensation from epiglottis

Answer 29

arch 4/6

-vagus n (CN X)

Question 30

muscles of tongue formed from _______

Answer 30

muscles of tongue formed from OCCIPITAL SOMITES

NOT pharyngeal arches

Question 31

arch 6: artery, skeletal, muscles, CN

Answer 31

• ductus arteriosus, roots of pulmonary arteries
• laryngeal cartilages
• instrinsic muscles of the larynx
• recurrent laryngeal branch of vagus (CN X)