Embryology

Question 1

Blastocyte

Answer 1

Hollow ball with 2 layers - trophoblast on the outside and Embryoblast on the inside

Question 2

Cytodifferentiation

Answer 2

Development of different cell types

Question 3

Ectoderm

Answer 3

Layer in trilaminar embyonic disc derived from epiblast layer and lining stomodeum (outer)

Question 4

Endoderm

Answer 4

Layer in trilaminar embryonic disc derived from hypoblast layer (inner)

Question 5

Epiblast Layer

Answer 5

Superior layer in bilaminar disc (high columnar cells)

Question 6

Histodifferentiation

Answer 6

Development of different tissue types

Question 7

Hypoblast Layer

Answer 7

Inferior layer in bilaminar disc (cuboidal cells)

Question 8

Meiosis

Answer 8

Process of reproductive cell production that ensures correct number of chromosomes

Question 9

Mitosis

Answer 9

Cell division that occurs in phases and creates 2 daughter cells

Question 10

Mesoderm

Answer 10

Embryonic layer located between endoderm and ectoderm (middle)

Question 11

Morphodifferentiation

Answer 11

Development of the differing structure or shape

Question 12

Morula

Answer 12

Ball of cells

Question 13

Neural crest cells

Answer 13

Specialized group of cells developed from the neuroectoderm that migrate from the crests of the neural folds and disperse to specific sites within the mesenchyme

Question 14

Neuroectoderm

Answer 14

Specialized group of cells that differentiates from the ectoderm

Question 15

Primitive Streak

Answer 15

Furrowed, rod-shaped thickening in middle of embryonic disc. Causes the disc to have bilateral symmetry

Question 16

Somites

Answer 16

Paired cuboidal aggregates of cells that develop along the midline of the neural tube

Question 17

Zygote

Answer 17

Fertilized Egg

Question 18

Branchial Arches

Answer 18

Six stacked bilateral swellings of tissue that appear inferior to stomodeum, including mandibular arch

Question 19

Branchial grooves

Answer 19

Grooves between neighboring branchial arches on each side of embryo

Question 20

Buccopharyngeal membrane (Oropharangeal membrane)

Answer 20

Membrane at cephalic end of embryo

Question 21

Globular process

Answer 21

Intermaxillary segment (philthrum); below the lateral nasal process

Question 22

Lateral nasal process

Answer 22

Tissue on outer part of nasal pits that forms nasal alae

Question 23

Mandibular arch

Answer 23

Lowest dental arch with mandibular teeth OR 1st branchial arch in embryo

Question 24

Mandibular symphysis

Answer 24

Midline area of mandible formed by fusing two mandibular processes

Question 25

Maxillary process

Answer 25

Prominence from mandibular arch that grows superiorly and anteriorly on each side of stomodeum

Question 26

Meckel's cartilage

Answer 26

Cartilage that forms within each side of mandibular arch and that dissapears as bony mandible forms

Question 27

Median nasal process

Answer 27

Middle part of the tissue growing around nasal placodes located between nasal pit

Question 28

Nasal pit

Answer 28

Depressions in center of each nasal placode that evolve into the nasal cavities

Question 29

Pharyngeal pouches

Answer 29

Four pairs of evaginations lining the pharynx between branchial arches

Question 30

Philthrum

Answer 30

Vertical groove on midline of upper lip

Question 31

Placodes

Answer 31

Areas of ectoderm found at location of developing special sense organs on the embryo

Question 32

Richert's cartilage

Answer 32

Forming within the 2nd branchial arch or hyoid arch and similar to that of the mandibular arch

Question 33

Stomodeum

Answer 33

Primitive mouth in embryo

Question 34

Copula

Answer 34

Formed from the fusion of mesenchyme of mainly the third and parts of the fourth branchial arch. Copula gradually overgrows the second branchial arch or hyoid arch to form the base of the tongue or posterior one third.

Question 35

Foramen cecum

Answer 35

Small pitlike depression located where sulcus terminalis points backward toward pharynx; beginning of thyroglossal duct

Question 36

Lateral lingual swellings

Answer 36

parts of developing tongue that form on each side of tuberculum impar

Question 37

Lateral palatine processes

Answer 37

Farther from the midline of the palatine process

Question 38

Median lingual sulcus

Answer 38

Midline depression on dorsal surface of the tongue

Question 39

Premaxila

Answer 39

Incisive bone - bone that bears the upper incisive teeth

Question 40

Primary palate

Answer 40

Anterior part of final palate derived from intermaxillary segment during prenatal development

Question 41

Secondary palate

Answer 41

Posterior part of final palate formed by fusion of two palatal shelves

Question 42

Sulcus terminalis

Answer 42

Groove located posteriorly on dorsal tongue surface

Question 43

Thyroglossal duct

Answer 43

Temporary tube that connects thyroid with tongue base during prenatal development

Question 44

Tuberculum impar

Answer 44

Initial part of developing tongue located in midline.