Embryology

Question 1

Pharyngeal arches form from _________

Answer 1

the migration and proliferation of neural crest cells

Question 2

Pharyngeal arches are separated by ________ and _________

Answer 2

pharyngeal grooves and clefts

Question 3

Outside covering of pharyngeal arches

Answer 3

ectoderm

Question 4

Inside lining of pharyngeal arches (one exception)

Answer 4

endoderm

-Arch 1 has oral ectoderm on inside

Question 5

what makes up the core of each arch?

Answer 5

mesenchyme

Question 6

Pharyngeal pouch

Answer 6

separates pharyngeal arches from the endoderm lined insides

Question 7

pharyngeal membrane

Answer 7

where ectoderm and endoderm come together at clefts/grooves

Question 8

1st pharyngeal arch, neural crest derivative

Answer 8

• Mandibular prominence (Meckel’s cartilage, mandible, malleus, incus, anterior ligament of malleus)
• Maxillary prominence?

Question 9

Mandibular prominence (5), neural crest derivative

Answer 9

• Meckel’s cartilage
• mandible
• malleus
• incus
• anterior ligament of malleus

Question 10

2nd pharyngeal arch (4), neural crest derivative

Answer 10

• lesser cornu of hyoid (superior hyoid)
• stylohyoid
• styloid process
• stapes

Question 11

3rd pharyngeal arch (2), neural crest derivative

Answer 11

body and greater cornu of hyoid (inferior hyoid)

Question 12

4th pharyngeal arch (1), neural crest derivative

Answer 12

laryngeal carliages

Question 13

1st pharyngeal arch = ?

Answer 13

mandibular

Question 14

2nd pharyngeal arch = ?

Answer 14

hyoid

Question 15

1st pharyngeal arch (2) (mesoderm derivatives)

Answer 15

• All muscles of mastication

- anterior belly of digastric

Question 16

2nd pharyngeal arch (2) (mesoderm derivatives)

Answer 16

• Muscles of facial expression

- posterior belly of digastric

Question 17

3rd pharyngeal arch (1) (mesoderm derivatives)

Answer 17

stylopharngeus

Question 18

4th/6th mesodermal arch (mesoderm derivatives) (3)

Answer 18

• pharyngeal constrictors
• soft palate muscles
• laryngeal muscles

Question 19

1st pharyngeal arch (innervation)

Answer 19

trigeminal nerve (V)

Question 20

2nd pharyngeal arch (innervation)

Answer 20

Facial nerve (VII)

Question 21

3rd pharyngeal arch (innervation)

Answer 21

Glossopharyngeal (IX)

Question 22

4th/6th pharyngeal arch (innervation)

Answer 22

vagus (X)

Question 23

1st pharyngeal pouch (endoderm) (2)

Answer 23

middle ear cavity

auditory tube

Question 24

2nd pharyngeal pouch (endoderm) (1)

Answer 24

palatine tonsil

Question 25

3rd pharyngeal pouch (endoderm) (2)

Answer 25

Inferior parathyroid glands | Thymus

Question 26

4th pharyngeal pouch (endoderm) (2)

Answer 26

superior parathyroid glands | ultimobranchial bodies

Question 27

Pharyngeal groove 1

Answer 27

external acoustic meatus

Question 28

Pharyngeal groove 2-4

Answer 28

cervical sinus --> cervical vesicle

Question 29

Thyroid develops from...

Answer 29

endoderm between pharyngeal arch 1 and 2

Question 30

Median lingual swelling derived from...

Answer 30

1st arch

Question 31

Lateral lingual swellings (anterior 2/3 of tongue) derived from...

Answer 31

1st arch

Question 32

Copula derived from...

Answer 32

2nd arch

Question 33

Hypopharnygeal eminence (posterior 1/3 of tongue) derived from...

Answer 33

3rd and 4th arches

Question 34

The tongue is well formed by week ________

Answer 34

10

Question 35

Skeletal muscles of the tongue derived from ___________

Answer 35

occipital somites

Question 36

________ nerve pulled with occipital somites to innervate (motor) skeletal muscles of the tongue

Answer 36

hypoglossal

Question 37

Anterior 2/3 of the tongue: - Somatosensory? - Special Sensory?

Answer 37

somatosensory = V2 | special sensory = VII

Question 38

Posterior 1/3 of tongue - Somatosensory? - Special sensory?

Answer 38

somatosensory = IX and X | special sensory = IX

Question 39

Motor innervation of the tongue

Answer 39

XII

Question 40

Papillae of tongue form by week ________

Answer 40

8

Question 41

4 types of tastebuds

Answer 41

1) filiform 2) fungiform* 3) folliate* 4) circumvallate* * = contain tastebuds

Question 42

Face formation begins in week ______

Answer 42

4

Question 43

Median nasal prominences fuse between week ____ - ____

Answer 43

6-10

Question 44

Median nasal prominence (derived from maxillary prominence) gives rise to

Answer 44

- Bridge of the nose | - Intermaxillary segment (philtrum, upper jaw with 4 incisors, primary palate)

Question 45

philtrum derived from...

Answer 45

intermaxillary segment (MxP)

Question 46

upper jaw and 4 incisors derived from...

Answer 46

intermaxillary segment (MxP)

Question 47

Primary palate derived from...

Answer 47

intermaxillary segment (MxP)

Question 48

Fusion of maxillary prominence with the intermaxillary segment results in...

Answer 48

- smooth upper lip | - fusion of primary and secondary palate

Question 49

Alae derived from

Answer 49

Lateral nasal prominence (MxP)

Question 50

Failure of the lateral nasal prominence to fuse with the maxillary prominence results in...

Answer 50

facial cleft

Question 51

Secondary palate derived from...

Answer 51

fusion of palatine shelves that grow from the maxillary prominence

Question 52

Secondary palate gives rise to...

Answer 52

majority of hard palate, all of soft palate

Question 53

Primary palate gives rise to...

Answer 53

anterior hard palate

Question 54

Palatine shelves fuse around week ______ when ________

Answer 54

9 | the mandible "drops" tongue

Question 55

Palatine shelves fuse with eachother and with _______

Answer 55

primary palate anteriorly

Question 56

Secondary palate formation complete at week ______

Answer 56

12

Question 57

Cleft lip results when...

Answer 57

intermaxillary segment and maxillary prominence fail to fuse (can be unilateral or bilateral)

Question 58

Cleft palate results when...

Answer 58

palatal shelves fail to fuse

Question 59

Oblique cleft results when...

Answer 59

lateral nasal prominence fails to fuse with the maxillary prominence