Gen. Embryology

Question 1

Pharyngeal Arch / Branchial Arch

Answer 1

1- V- Meckels cartilage; muscle of mastication
2- VII- reicherts cartilage; muslce of facial expression
3- IX- Greater cornu & body of hyoid
4- X- Pharyngeal & Laryngeal muscles & cartilage
6- X- Laryngeal muscles

Question 2

Pharyngeal Pouch

Answer 2

1- MAT : Middle Ear, Auditory tube , Tympanic Membrane
2- Palatine tonsil & Lymphatic nodule
3.- Thymus & Inferior Parathyroid Gland
4- Superior Parathyroid & Ultimobranchial body

Question 3

Pharyngeal Cleft

Answer 3

1- EAM

2,3,4- Cervical sinus

Question 4

Tongue Development

Ant. 2/3

Answer 4

1st Pharyngeal Arch

Lateral Lingual Swelling & Tuberculum Impar

Question 5

Post. 1/3 tongue development

Answer 5

2nd & 3rd Pharyngeal Arch + Copula

Question 6

1st Pharyngeal Arch divides into

Answer 6

Mandibular Process

Maxillary Process

Question 7

Bilaminar germ disc (primitive streak)

Answer 7

Trilaminar Germ Disc

Question 8

ECTODERM

Answer 8

Enamel
Skin
Nervous System

Question 9

Mesoderm

Answer 9

Dentin
Pulp
Muscle
Skeleta
Genitourinary

Question 10

Endoderm

Answer 10

Gastrointestinal

Respiratory

Question 11

Fetus Ductus Arteriosus

Answer 11

Ligamentem arteriosum

Question 12

Ductus venosus

Answer 12

Ligamentum venosum

Question 13

Foramen Ovale

Answer 13

Fossa Ovalis

Question 14

Umbilical vein & Arteries

Answer 14

Ligametum teres of the liver & Medial umbilical ligaments

Question 15

defects anodontia & supernumerary

Formation of Dental Lamina

Answer 15

Initiation (6th week)

Question 16

proliferation of both ectodermal & ectomesenchymal cells

Answer 16

Bud stage (8th wk)

Question 17

of cusp tips

Answer 17

Enamel knot

Question 18

betweem OEE & IEE

Answer 18

Stellate Reticulum

Question 19

defects : DEntinogenesis Imperfecta, amelogenesis imperfecta , macro/microdontisa

Answer 19

Morpho & Histodifferentiation

Question 20

Appositional Stage (14th week)

Answer 20

Chronological Order

1. Diff. ameloblast
2. Diff. odontoblast
3. Deposition of dentin matrix by odontoblasts
4. Depositipm of enamel matrix by ameloblasts

Question 21

• last product / final product of ameloblasts

- first protectiv ecovering

Answer 21

Primary Enamel Cuticle

Nasymyth’s Membrane

Question 22

fusion of IEE, OEE,, SR & SI
secondary enamel cuticle
forms JE
defects: enamel dysplasia, concrescensce, enamel pearls

Answer 22

REE
Appositional Stage (14th week)

Question 23

forms apical foramen

determines # of roots

Answer 23

Epithelial Diaphragm

Question 24

basic structural unit

Answer 24

Enamel rods / Enamel prism

Question 25

intertwining pathways of enamel rods

Answer 25

Gnarled enamel rod

Question 26

covers enamel rods
slightly more mineralized than enamel rod
fish scale appearance

Answer 26

Enamel rod sheath

Question 27

cements rods together

Answer 27

Interrod

Question 28

• appositional/ incremental growth of enamel

- marks primary calcification of enamel

Answer 28

Incremental Lines of Retzius

Question 29

lines of retries as they meet at the surface of enamel

Answer 29

Perikymata/ Imbrication Lines of Pickerill

Question 30

more pronounced incremental line

Answer 30

Neonatal Line

Question 31

crosses bands of retizius

appositional growth of enamel of 4um/day

Answer 31

Tranverse Striations

Question 32

alternate dark & light bands

Answer 32

Hunter shcreger bands

Question 33

originate from DEJ

lateral spread of caries

Answer 33

Enamel Tufts

Question 34

‼️‼️‼️BE‼️‼️‼️

cracks on surface of enamel
pathway for bacteria to penetrate the enamel

Answer 34

Enamel Lamellae

Question 35

extensionsof dentinal tubules that penetrate DEJ

DEJ hypersensitivity

Answer 35

Enamel Spindle

Question 36

scalloped for attachment

Answer 36

DEJ