Stephens Embryo lecture

Question 1

CN of Arch 1

Answer 1

trigeminal

Question 2

Skeletal of Arch 1

Answer 2

malleus, incus, maxilla, mandible, meckels

Question 3

Muscle of Arch 1

Answer 3

muscles of mastication

Question 4

CN of Arch 2

Answer 4

Facial nerve

Question 5

Skeletal of Arch 2

Answer 5

reichert’s cartilage, stapes, upper hyoid bone, lesser cornu

Question 6

Muscle of Arch 2

Answer 6

facial expression

Question 7

CN of Arch 3

Answer 7

Glossopharyngeal

Question 8

Skeletal of Arch 3

Answer 8

greater cornu, lower hyoid

Question 9

Muscle of Arch 3

Answer 9

stylopharyngeus

Question 10

CN of Arch 4

Answer 10

Vagus

Question 11

Skeletal of Arch 4

Answer 11

laryngeal and thyroid cartilage

Question 12

Muscle of Arch 4

Answer 12

pharyngeal and laryngeal mm.

Question 13

Pharyngeal pouch 1

Answer 13

eustation tube, tympanic membrane, and external acoustic meatus

Question 14

Pharyngeal pouch 2

Answer 14

tonsils, root of tongue

Question 15

Pharyngeal pouch 3

Answer 15

inferior parathyroid, thyroid

Question 16

Pharyngeal pouch 4

Answer 16

superior thyroid

Question 17

Cranioschisis

Answer 17

failure of occipital and parietal bones to form or close

Question 18

Microcephaly

Answer 18

small cranium due to early fusion of cranial sutures

Question 19

Macrocephaly

Answer 19

enlarged cranium secondary to hydrocephaly from early fusion of superior cranial sutures

Question 20

Apert Syndrome

Answer 20

premature fusion of coronal sutures
“tower skull”
associated with fetal alcohol syndrome

Question 21

Cleft chin

Answer 21

mandibular prominences partially or completely fail to fuse

Question 22

Anterior cleft deformity

Answer 22

failure of medial nasal and maxillary swelling to fuse

Question 23

Posterior cleft deformity

Answer 23

failure of palatine shelves to fuse

Question 24

Cleft lip

Answer 24

anterior deformity, more common in males

Question 25

Cleft palate

Answer 25

posterior deformity, more common in females

Question 26

Oblique facial cleft

Answer 26

failure of maxillary swelling to fuse with lateral nasal swelling (palatine shelves)

Question 27

What is exposed with an oblique facial cleft

Answer 27

nasolacrimal duct

Question 28

Median cleft lip and bifid nose

Answer 28

failure of medial nasal prominences to fuse

Question 29

Macrostomia and microstomia

Answer 29

dysfunction of maxillary and mandibular swelling

Question 30

Agathnia

Answer 30

dysgenesis of mandibular swelling

Question 31

Neurocranium

Answer 31

first 10 weeks | cradles the skull

Question 32

Viscerocranium- cartilaginous

Answer 32

forms brachial arches

Question 33

Viscerocranium- membranous

Answer 33

forms maxillary and mandibular processes of arch #1

Question 34

Stomodeum origin

Answer 34

ectoderm

Question 35

Stomodeum function

Answer 35

demarkation of anterior 2/3 of oral cavity vs posterior 1/3 of oral cavity

Question 36

Facial Swellings

Answer 36

frontal prominence, maxillary prominence, and mandibular prominence

Question 37

Frontal prominence

Answer 37

forms forhead, dorsum and apex of nose | forms nasal placodes

Question 38

Nasal placodes form..

Answer 38

form medial and lateral nasal prominence

Question 39

Medial nasal prominence

Answer 39

forms medial nose, upper lip, and philtrum

Question 40

Lateral nasal prominence

Answer 40

alae of nose

Question 41

Maxillary prominence

Answer 41

forms lateral part of upper lip, lateral jaw, and secondary palate

Question 42

Nasolacrimal groove

Answer 42

oblique furrow formed between lateral nasal prominence and maxillary prominence

Question 43

Mandibular prominence

Answer 43

forms lower jaw and lower lip

Question 44

Mimetic muscles

Answer 44

muscles of facial expression from arch 2 that invade arch 1 swellings

Question 45

Nose formation

Answer 45

nasal palcodes --> nasal pits --> nasal sac

Question 46

Nasal sac

Answer 46

primitive nasal cavity

Question 47

Oronasal membrane

Answer 47

separates primitive nasal cavity from primitive oral cavity

Question 48

What does oronasal membrane breakdown into

Answer 48

primitive choanae

Question 49

Intermaxillary process

Answer 49

forms nasal septum and primary palate

Question 50

How is intermaxillary process formed

Answer 50

fusion of medial and nasal prominences

Question 51

Primary palate

Answer 51

forms upper lip

Question 52

How is primary palate formed

Answer 52

from deep portions of intermaxillary process

Question 53

Incisive foramen

Answer 53

boundary between primary and secondary palate and distinguishes between anterior and posterior cleft deformities

Question 54

How is secondary palate formed

Answer 54

formed by palatine shelves (lateral palatine processes) | Shelves fuse with each other and form secondary palate