Part 2

Question 1

As implantation progresses, the inner cell mass organizes into this.

Answer 1

Bilayer Embryonic Disc

Question 2

The superficial layer of the bilayer embryonic disc consisting of high columnar cells related to the amniotic cavity.

Answer 2

Epiblast

Question 3

The deep layer of the bilayer embryonic disc consisting of small cuboidal cells facing the blastocyst cavity.

Answer 3

Hypoblast

Question 4

Formed during the first two to three weeks of development; lie outside the blastodisc and provide protection and nourishment for the embryo/fetus.

Answer 4

Extraembryonic Membranes

Question 5

The first extraembryonic membrane to appear; participates in the formation of the gut and is the source of the earliest blood cells and blood vessels.

Answer 5

Yolk Sac

Question 6

The “water bag”; formed when cells in the epiblast portion of the blastodisc migrate to line the inner surface of the amniotic cavity.

Answer 6

Amnion

Question 7

The epiblast forms the floor of this.

Answer 7

Amniotic Cavity

Question 8

By week 10, the amnion has mushroomed and envelops the embryo in a protective environment of this.

Answer 8

Amniotic Fluid

Question 9

Cells from the yolk sac endoderm form a layer of connective tissue.

Answer 9

Extraembryonic Mesoderm

Question 10

The outer extraembryonic membrane; formed by the cellular trophoblast and extraembryonic mesoderm.

Answer 10

Chorion

Question 11

The extraembryonic coelom is called this when the chorion forms.

Answer 11

Chorionic Cavity

Question 12

Extends from the chorion into the endometrial lacunae to establish the structural framework for the development of the placenta.

Answer 12

Chorionic Villi

Question 13

Villi that grow more strongly on the former implantation pole.

Answer 13

Chorion Frondosum

Question 14

Villi in other areas that decrease in number.

Answer 14

Chorion Laeve

Question 15

Trophoblastic channels that allow maternal blood to percolate through.

Answer 15

Lacunae

Question 16

Forms as a small out-pocketing of embryonic tissues at the caudal end of the yolk sac. Contributes the the structural base for the umbilical cord that links the embryo to the placenta and ultimately becomes part of the urinary bladder.

Answer 16

Allantois

Question 17

The embryo is connected to the placenta by this.

Answer 17

Body Stalk

Question 18

Where the yolk sac attaches to the endoderm of the embryo

Answer 18

Yolk Stalk

Question 19

The yolk stalk and the body stalk together.

Answer 19

Umbilical Cord

Question 20

Transport deoxygenated blood to the placenta

Answer 20

Umbilical Arteries

Question 21

Return oxygenated blood to the embryo.

Answer 21

Umbilical Vein

Question 22

Composed of inner epithelial endometrium and outer muscular myometrium.

Answer 22

Uterine Cavity

Question 23

Area of the endometrium where the placenta is in contact.

Answer 23

Decidua Basalis

Question 24

The rest of the endometrium where villi are absent; isolates the embryo from the uterine cavity.

Answer 24

Decidua Capsularis

Question 25

The endometrium on the wall opposite to the embryo.

Answer 25

Decidua Parietalis

Question 26

During week 3, cells begin to migrate. The bilaminar embryonic disc is converted into a trilaminar embryonic disc.

Answer 26

Gastrulation

Question 27

The embryo during gastrulation.

Answer 27

Gastrula

Question 28

Through the process of gastrulation, cells of the epiblast give rise to all three of these.

Answer 28

Germ Layers

Question 29

The cells remaining in the epiblast form this.

Answer 29

Ectoderm

Question 30

Some mesenchyme forms this.

Answer 30

Mesoderm

Question 31

Cells from the epiblast further displace the hypoblast, forming this in the roof of the yolk sac.

Answer 31

Endoderm

Question 32

Cells of the epiblast move toward the median place of the dorsal aspect of the blastodisc to this region.

Answer 32

Primitive Streak

Question 33

A tissue consisting of loosely arranges cells suspended in a gelatinous matrix. Forms supporting tissues of the embryo.

Answer 33

Mesenchyme

Question 34

The fourth to eighth weeks of the development constitute most of the embryonic period when all major external and internal structures are established.

Answer 34

Organogenesis

Question 35

The three layers of the embryo folds form an internal cavity, which becomes the epithelial lining of the GI and respiratory tracts.

Answer 35

Primitive Gut

Question 36

Segments of the primitive gut.

Answer 36

Foregut, Midgut, Hindgut

Question 37

The foregut develops into 5 folds.

Answer 37

Pharyngeal Arches

Question 38

The differentiation of ectoderm into brain and spinal cord.

Answer 38

Neurulation

Question 39

The ectoderm at the cephalic end thickens and forms a neural plate that invaginates and pinches off, forming this.

Answer 39

Neural Tube

Question 40

Parts of the neural tube.

Answer 40

Primary Vesicles

Question 41

The three primary vesicles

Answer 41

Forebrain, Midbrain, Hindbrain

Question 42

Two lateral outgrowths on each side of the forebrain. The primordia of the retinae and optic nerves.

Answer 42

Optic vesicle

Question 43

Mesodermal cells beneath the early primitive streak aggregate, forming a rod of mesodermal cells. The first axial support of the embryo; is eventually replaced by the vertebral column.

Answer 43

Notochord

Question 44

Paired cuboidal bodies that first appear in the future occipital region of the embryo, then soon develop craniocaudally to form sclerotomes, myotomes, and dermatomes, and give rise to most of the axial skeleton and associated musculature as well as the dermis of the skin.

Answer 44

Somite

Question 45

Paired, longitudinal channels developed during the third week fuse to form this.

Answer 45

Heart Tube

Question 46

Surrounds the heart tube.

Answer 46

Pericardium

Question 47

Three vascular structures most important in the transitional circulation.

Answer 47

Ductus Arteriosus, Foramen Ovale, Ductus Venosus.

Question 48

The right umbilical branch passes to the right side of the liver and is joined by this.

Answer 48

Portal Vein

Question 49

Highly oxygenated, nutrient rich blood returns from the placenta via this.

Answer 49

Umbilical Vein

Question 50

Returns blood to the placenta.

Answer 50

Umbilical Arteries

Question 51

The left umbilical branch passes directly into the ductus venosus, which connects the umbilical vein to this.

Answer 51

Inferior Vena Cava