Embryology

Question 1

PA 1 - neural crest cells

Answer 1

midbrain rhombomeres 1 and 2

Question 2

PA 2 - neural crest cells

Answer 2

rhombomere 4

Question 3

PA 3 - neural crest cells

Answer 3

rhombomere 6

Question 4

PA 4 - neural crest cells

Answer 4

rhombomere 8

Question 5

PA 1 - nerve

Answer 5

V trigeminal Branches: - Ophthalmic - Mx - Md

Question 6

PA 1 - muscles

Answer 6

Mastication - temporal, masseter, medial/lateral pterygoids Mylohyoid Anterior digastric Tensor tympani Tensor veli palatini

Question 7

PA 1 - skeleton

Answer 7

Meckel’s cartilage Malleus Incus

Question 8

PA 2 - nerve

Answer 8

VII facial - chorda tympani - taste

Question 9

PA 2 - muscles

Answer 9

Facial Expression - buccinator, auricularis, frontalis, platysma, orbicularis oculi, orbicularis ori Posterior digastric Stylohyoid Stapedius

Question 10

PA 2 - skeleton

Answer 10

Reichert’s cartilage - stapes - styloid - lesser hyoid

Question 11

PA 3 - Nerve

Answer 11

IX glossopharyngeal - sensation: pharynx, mid ear, root of tongue - Taste root of tongue

Question 12

PA 3 - muscles

Answer 12

stylopharyngeus

Question 13

PA 3 - skeleton

Answer 13

greater hyoid

Question 14

PA 4-6 - nerve

Answer 14

X vagus - parasympathetic innervation

Question 15

PA 4-6 - muscles

Answer 15

Cricothyroid Levator veli palatini Contrictors of pharynx Larynx muscles

Question 16

PA 4-6 - skeleton

Answer 16

laryngeal cartilages

Question 17

pharyngeal pouches are where?

Answer 17

between arches, interior

Question 18

pharyngeal grooves/clefts are where?

Answer 18

between arches, exterior

Question 19

Fate of 1st pouch

Answer 19

external auditory meatus/tympanic cavity eustachian tube

Question 20

Fate of 2nd pouch

Answer 20

obliterated by tonsil

Question 21

fate of 3rd pouch

Answer 21

inferior parathyroid thymus

Question 22

fate of 4-5 pouches

Answer 22

superior parathyroid ultimobranchial body (C cells thyroid)

Question 23

Fate of 1st groove/cleft

Answer 23

external auditory meatus/tympanic cavity eustachian tube

Question 24

Fate of clefts/grooves 2-6

Answer 24

dissapear

Question 25

What do the neural crest cells differentiate into (general)?

Answer 25

Nerves Bones and CT of head Cells Endocrine Eyes Heart

Question 26

What nerve tissue is derived from neural crest cells?

Answer 26

ganglia of CNS Craniospinal sensory and parasympathetic ganglia GI nerves Glial cells - Schwann cells Carotid body

Question 27

What bones and CT of the head are derived from neural crest cells?

Answer 27

meninges skull mx md larynx hyoid auditory ossicles Teeth - dentin, cementum, pulp, PDL PHARYNGEAL ARCHES

Question 28

Which specific cell types are derived from neural crest cells?

Answer 28

melanocytes C (calcitonin) cells of thyroid adipocytes

Question 29

Which parts of the endocrine system are derived from neural crest cells?

Answer 29

C (calcitonin) cells of thyroid Adrenal medulla

Question 30

Which parts of the eye are derived from neural crest cells?

Answer 30

pigmented retina cells smooth muscle cornea

Question 31

Which parts of the heart are derived from neural crest cells?

Answer 31

carotid body Middle portion cardiac outflow tract

Question 32

Which germ cell layers form the pharyngeal arches?

Answer 32

Lateral plate mesoderm paraxial mesoderm neural crest cells

Question 33

Fates of neuroectoderm

Answer 33

posterior pituitary pineal body retina CNS

Question 34

Fates of intermediate plate mesoderm

Answer 34

urogenital system

Question 35

Fates of lateral plate mesoderm

Answer 35

Heart Hematopoetic system lymphoid system Connective tissue spleen adrenal cortex pharyngeal arches Serous membranes (pleura, pericardium, peritoneum)

Question 36

Fates of paraxial mesoderm

Answer 36

muscles of entire body Bones of most of body (except head) dermis pharyngeal arches connective tissue

Question 37

Fates of ectoderm

Answer 37

Epidermis hair nails mammary glands anterior pituitary lens of eye inner ear tooth enamel

Question 38

Fates of endoderm

Answer 38

GI lining lungs liver pancreas gallbladder bladder thyroid follicular cells tympanic cavity tonsils parathyroid

Question 39

What happens during the embryonic period phase 1? timeline?

Answer 39

weeks 0-3 - cellular proliferation and migration Wk 1: morula to blastocyst Wk 2: formation of bilaminar disk Day 14-16: Gastrulation - form trilaminar disk

Question 40

What happens during embryonic period phase 2? timeline?

Answer 40

Weeks 4-8 - differentiation Formation of neural tube Differentiation of mesoderm Folding PA formation Development of head, face, OC

Question 41

What happens during embryonic phase 3? timeline?

Answer 41

Growth and maturation Weeks 8-40 (delivery)

Question 42

role of PA 1 in tongue development

Answer 42

lingual swellings - mucosa of body N: V trigeminal

Question 43

Role of PA 2 in tongue development

Answer 43

copula - overgrown

Question 44

Role of PA3 in tongue development

Answer 44

Large ventral part of hypopharyngeal eminence - mucosa of most of root N: IX glossopharyngeal

Question 45

Role of PA4 in tongue development

Answer 45

Small dorsal part of hypopharyngeal eminence - mucosa of tiny part of root N: X vagus

Question 46

Role of somites in tongue development

Answer 46

myoblasts - muscles of tongue N: XII hypoglossal